Endangered Species Act Section 7(a)(2) Biological Opinion and Magnuson–Stevens Fishery Conservation and Management Act Essential Fish Habitat Response San Clemente Shoreline Protection Project
NMFS Consultation Number: WCRO-2022-02052
Action Agency: U.S. Army Corps of Engineers
Affected Species and NMFS’ Determinations:
ESA-Listed Species Status
Is Action
Likely to
Adversely
Affect
Species?
Is Action
Likely to
Jeopardize
the Species?
Is Action
Likely to
Adversely
Affect
Critical
Habitat?
Is Action Likely
to Destroy or
Adversely
Modify Critical
Habitat?
Green sea turtle;
East Pacific Distinct
Population Segment
(Chelonia mydas)
Threatened Yes No N/A N/A
Consultation Conducted By: National Marine Fisheries Service, West Coast Region Issued By: Chris Yates
Assistant Regional Administrator for Protected Resources West Coast Region
National Marine Fisheries Service
Date: May 8, 2023
ATTACHMENT 8
1 TABLE OF CONTENTS
1. Introduction 2
1. Background 2
2. Consultation History 2
3. Proposed Federal Action 5
2. Endangered Species Act: Biological Opinion And Incidental Take Statement 11
1. Analytical Approach 12
2. Rangewide Status of the Species 13
3. Action Area 18
4. Environmental Baseline 18
5. Effects of the Action 22
6. Cumulative Effects 31
7. Integration and Synthesis 31
8. Conclusion 32
9. Incidental Take Statement 33
1. Amount or Extent of Take 33
2. Effect of the Take 34
3. Reasonable and Prudent Measures 34
4. Terms and Conditions 35
10. Conservation Recommendations 40
11. Reinitiation of Consultation 41
3. Data Quality Act Documentation and Pre-Dissemination Review 42
1. Utility 42
2. Integrity 42
3. Objectivity 42
4. References 43
2 1. INTRODUCTION
This Introduction section provides information relevant to the other sections of this document and is incorporated by reference into Sections 2 and 3, below.
1. Background
The National Marine Fisheries Service (NMFS) prepared the biological opinion (opinion) and incidental take statement (ITS) portions of this document in accordance with section 7(b) of the Endangered Species Act (ESA) of 1973 (16 U.S.C. 1531 et seq.), as amended, and implementing regulations at 50 CFR part 402.
We previously completed an essential fish habitat (EFH) consultation on the proposed action in September 2010, in accordance with section 305(b)(2) of the Magnuson–Stevens Fishery Conservation and Management Act (MSA) (16 U.S.C. 1801 et seq.) and implementing regulations at 50 CFR part 600.
We completed pre-dissemination review of this document using standards for utility, integrity, and objectivity in compliance with applicable guidelines issued under the Data Quality Act (DQA) (section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001, Public Law 106-554). The document will be available within 2 weeks at the NOAA Library Institutional Repository [https://repository.library.noaa.gov/welcome]. A complete record of this consultation is on file at the Long Beach, California office.
2. Consultation History
NMFS previously reviewed the U.S. Army Corps of Engineers (USACE) Draft Environmental Impact Statement / Environmental Impact Report (EIS/EIR) for the San Clemente Shoreline Protection Project (Project), and provided comments to the USACE on September 20, 2010, pursuant to our responsibilities under the National Environmental Policy Act, Magnuson-Stevens Fishery Conservation and Management Act, Endangered Species Act (ESA), Marine Mammal Protection Act, and the Fish and Wildlife Coordination Act. In addition, NMFS Headquarters responded to the USACE’s Final EIS/EIR via letter dated September 30, 2011, which summarized a number of concerns regarding the Project. In particular, NMFS noted that the USACE’s response was inconsistent with key aspects of the essential fish habitat (EFH) recommendations we had provided in September 2010.
The USACE responded to our September 2011 letter on March 23, 2012 and addressed some of our concerns regarding the rocky reef monitoring and mitigation approach. The USACE indicated that a reasonable worst-case scenario of one acre of reef burial was used to estimate their contingency costs for mitigation. The USACE committed to implementing the rocky reef/surfgrass monitoring, mitigation, and reporting plan described in Appendix B of the 3 EIS/EIR, and indicated that it may be revised during the Preconstruction, Engineering and Design (PED) Phase. The USACE confirmed that the monitoring and analytical methods used would be adequate to identify and accurately measure impacts from the beach nourishment effort. If a more comprehensive biological survey of the project area would be required to accomplish the above, it would be accomplished during the PED phase. The final monitoring and mitigation reporting plan would ensure that appropriate mitigation sites are available to address potential impacts, and that the success criteria and analytical methods used are adequate to demonstrate a difference between impact/mitigation sites and control sites. To continue to work cooperatively throughout the final project planning and construction phases, the USACE indicated they would provide a copy of the final PED phase surveys and the monitoring plans to NMFS and other agencies for review.
USACE staff provided an electronic mail update on April 27, 2020, indicating they were in the PED phase, and shared a preliminary nearshore bottom habitat and submerged aquatic vegetation assessment (Nearshore Wetland Surveys 2018) and a monitoring report for the first year of preconstruction surfgrass monitoring (Ecomarine Consulting LLC and Anghera Environmental, 2019). NMFS staff noted during an interagency teleconference in June 2020 that the preconstruction surfgrass monitoring that had been conducted had not been coordinated for agency review as the USACE had committed to. In addition, we noted that Nearshore Wetland Surveys (2018) observed more rocky reef habitat within the project impact footprint than the estimate provided in the Final EIS/EIR. Moreover, we indicated that the surfgrass transects were not representative of the project impact site. Two of the three transects were not in the anticipated project impact footprint, and one transect was placed in the outermost portion of the anticipated project impact footprint. USACE staff followed up on June 4, 2020, indicating that the USACE would be revising the monitoring, mitigation, and reporting plan (MMRP), and would provide NMFS and other agencies an opportunity to review. On October 28, 2021, USACE staff provided the monitoring report for the two-year pre-construction surfgrass monitoring (Ecomarine Consulting LLC and Anghera Environmental, 2020).
NMFS received a letter on August 16, 2022, from the USACE requesting initiation of informal consultation under Section 7(a)(2) of the ESA regarding the effects of the Project on the federally ESA threatened East Pacific Distinct Population Segment (DPS) of green sea turtles (Chelonia mydas). The letter requested concurrence that the Project is not likely to adversely affect the federally threatened East Pacific DPS of green sea turtles under the ESA.
In response to the USACE’s August 2022 letter, NMFS staff requested additional information on August 30, 2022, to support the consultation request, and USACE staff responded on September 15 and 25, 2022. These responses clarified the avoidance and minimization measures proposed in the August 2022 letter, and status of the rocky reef monitoring and mitigation approach. To supplement the pre-construction monitoring dataset generated in 2018 to 2020, the USACE proposed to conduct additional monitoring in the pre-construction phase, but did not provide an updated MMRP. Based upon the information provided and available at the time, NMFS staff responded on September 30, 2022, indicating that adverse effects to nearshore rocky reef 4 resources may make it difficult to conclude that effects to ESA-listed green sea turtles would be insignificant and/or discountable. In order to better understand the extent of green sea turtle foraging habitat that may be exposed to Project effects, NMFS staff requested that the USACE quantify the amount of rocky reef habitat in the sediment equilibrium footprint, which is the predicted area of potential sedimentation effects. Specifically, we requested quantification of the rocky reef area as observed in a 2018 memorandum regarding pre-construction monitoring for rocky reef and surfgrass habitat (Nearshore and Wetland Surveys, 2018). We also posed additional questions to help inform our effects analysis. USACE staff responded by email on November 3, 2022, with the rocky reef spatial data associated with the 2018 survey.
After considering the information in the August 16, 2022, letter, and additional information exchanges that had occurred through the interagency coordination process, we responded to the USACE in a January 6, 2023, letter that we were not able to concur with the USACE’s effect determination for green sea turtles, and that we would prepare a biological opinion on the Project, in accordance with the standards and procedures for formal consultation under section 7 of the ESA as described in 50 CFR §402 et seq. For the purposes of initiating and completing formal ESA consultation on the Project, we evaluated the information provided by USACE through informal consultation and indicated that USACE had satisfied the requirements for initiating formal consultation under 50 CFR §402.14(c), and we considered formal consultation to have been initiated as an outcome of the conference call between NMFS and USACE staff on December 9, 2022.
On April 5, 2023, the USACE provided new information that indicated several artificial reef structures occur within the borrow site offshore Oceanside. After interagency staff discussion and additional email correspondence, the USACE indicated on April 18, 2023, that the USACE would establish a 300 foot operational buffer between the artificial reef modules and along the reef depth contour.
On July 5, 2022, the U.S. District Court for the Northern District of California issued an order vacating the 2019 regulations that were revised or added to 50 CFR part 402 in 2019 (“2019 Regulations,” see 84 FR 44976, August 27, 2019) without making a finding on the merits. On September 21, 2022, the U.S. Court of Appeals for the Ninth Circuit granted a temporary stay of the district court’s July 5 order. On November 14, 2022, the Northern District of California issued an order granting the government’s request for voluntary remand without vacating the 2019 regulations. The District Court issued a slightly amended order two days later on November 16, 2022. As a result, the 2019 regulations remain in effect, and we are applying the 2019 regulations here. For purposes of this consultation and in an abundance of caution, we considered whether the substantive analysis and conclusions articulated in the biological opinion and incidental take statement would be any different under the pre-2019 regulations. We have determined that our analysis and conclusions would not be any different. 5 3. Proposed Federal Action
Under the ESA, “action” means all activities or programs of any kind authorized, funded, or carried out, in whole or in part, by Federal agencies (see 50 CFR 402.02). Under the MSA, “Federal action” means any action authorized, funded, or undertaken, or proposed to be authorized, funded, or undertaken by a Federal agency (see 50 CFR 600.910).] The Project purpose is to provide shoreline protection through nourishment of the beach near the San Clemente Pier. The USACE has determined that developing and maintaining the beach is needed to prevent beach erosion that results from winter storms and prevent damage to adjacent beachfront structures, including the heavily used rail line that runs along the beach through the City of San Clemente (City). In addition to the above, the USACE has determined that the loss of sand at the beach would have an impact on beach recreation, which contributes to the local economy, and would reduce the ecological functioning of the sand beach/littoral zone.
The Project involves dredging sediment from a borrow site offshore Oceanside Harbor, transporting the dredged material by barge offshore the nourishment site, and placing it at San Clemente Beach. Estimates based on regional monitoring suggest the beach nourishment fill will last about 6 years on average. Therefore, additional maintenance nourishment efforts will occur approximately every 6 years when the shoreline reaches the base beach width over the 50 year project life. Figure 1 shows the general location of the sediment placement in San Clemente and borrow site offshore of Oceanside. Figure 2 shows a map of the borrow site offshore Oceanside Harbor. The borrow site (Borrow Area 2) is approximately 940 acres, with a 128 acre area inside the borrow site (Borrow Area 2A) that contains the more desirable material. The USACE proposes to use Area 2A as the sediment source for the first nourishment event. Figure 3 indicates the proposed dredging offset used by the USACE to avoid the artificial reefs that occur within the borrow area.
6 Figure 1. Project location map illustrating sediment placement location in San Clemente and borrow site offshore of Oceanside.
7 Figure 2. Oceanside Borrow Site. Dredging will be conducted in Area 2A. 8 Figure 3: Oceanside Borrow Area 2A – Artificial Reef Dredging Project.
The Project will nourish approximately 3,412 feet (1,040m) of shoreline within the City. The nourishment area is approximately centered about the San Clemente Pier and extends from TStreet to Linda Lane. The design beach berm elevation is +17 feet mean lower low water (MLLW), and the design beach width is 50 ft (15m). The first dredge and beach placement event will involve 250,000 cubic yards (cy) of beach compatible sand, with re-nourishment intervals projected every 5 to 6 years at approximately the same volumes. The ensuing intervals and quantities will largely be dependent on rate of beach erosion and funding availability. Beach design would be optimized based on lessons learned and resulting beach morphology following post-placement of the initial fill stage. As a result, future sediment volumes may change.
The Project will be constructed with hopper dredging equipment with pump ashore capability and conventional earthmoving equipment. The hopper dredge will be filled at the designated borrow site approximately one mile offshore of Oceanside and hauled approximately 21 miles (35 km) to San Clemente. The specific hopper dredge vessel and its hold capacity is unknown at this time. Based upon a project clarification provided by email, the USACE anticipates that the hopper dredge will take 75-80 round trips between the sediment borrow site offshore Carlsbad and placement site in San Clemente. Anticipated vessel speed of the unloaded hopper transiting to the Oceanside borrow area would be approximately 11-13 knots, and 8-10 knots when loaded 9 with sediment and transiting to San Clemente. No support vessels are anticipated to be needed during transit. At the receiver beach, the dredge will be attached to a moored floating section of pipeline extending 1,500 ft (457 m) to the shoreline. The material would be resuspended and discharged through the on-board pumping system to the receiver site. During construction, onshore sediment placement will utilize berms to minimize nearshore impacts and retain sediments on the beach.
The hopper dredge requires a monobuoy to discharge its sand onto the beach. A monobuoy is a floating pipeline connection platform that is moored to the seafloor and interconnects with a steel sinker pipeline that carries the slurry along the seafloor to the beach. For this Project, the monobuoy would be anchored in at least 25 ft (7.6 m) of water, between 2,500 and 5,000 ft (762 to 1,524 m) from shore, in the appropriate location in relation to sensitive resources and engineering considerations. From one monobuoy location, sand can be pumped directly onshore and up to approximately 2,000 ft (610 m) alongshore in either direction. One to two support tugs will be utilized to assist the hopper dredge hook up to the monobuoy. One to three derrick barges will be used at the beginning and end of construction to install and remove the pipeline. These support vessels will limit their speed to inside wake zone speeds.
Dredging would be performed 24 hours a day, 7 days a week. Shore equipment would work 12 hours a day, 7 days a week. The Project duration is estimated at 46 working days over the course of 4 months. The first dredging and fill event is scheduled to occur in late Fall/Winter 2023, with subsequent fill events planned to occur at intervals dictated by funding availability and need over a 50-year time horizon. Prior to each subsequent dredge and fill event, the USACE will evaluate whether any changed conditions have occurred to the environmental baseline or project effects that would trigger the need for a new consultation.
The following measures will be implemented by USACE to avoid or minimize impacts to the federally threatened East Pacific DPS of green sea turtles.
1. During dredging, transit to and from the Oceanside Borrow Site, and placement of dredged material at the Placement Area, a qualified biologist or qualified monitor with experience monitoring green sea turtles will be onboard the hopper dredge to monitor for the presence of green sea turtles. The green sea turtle monitor will identify and communicate if there is a need to cease or alter operations to avoid impacts to green sea turtles.
2. During dredging, the biological monitor will periodically check in the hopper for the presence of green sea turtles. The biological monitor will also be equipped with a VHF radio to communicate with bridge officers, whose elevated vantage point is the best place on the hopper dredge to observe the hopper. If any evidence of turtles is detected, the bridge crew will immediately communicate with the biological monitor. 10 3. Nighttime lighting will illuminate an approximately 50 to 100 foot perimeter during dredging and placement operations. During nighttime operations, the biological monitor will visually observe the lighted perimeter for turtle presence.
4. The biologist or monitor will clear the dredging area and confirm no green sea turtles are present 30 minutes prior to the startup of dredging operations.
5. If a green sea turtle is observed within the vicinity of the project site during project operations, all appropriate precautions shall be implemented to avoid or minimize unintended impacts. These precautions include, but are not limited to:
• Cessation of operations within 100 feet of an observed green sea turtle; • Operations may not resume until the green sea turtle has departed the monitoring zone by its own accord or has not been observed for a 15-minute period of time; and
• Maneuver the hopper dredge to avoid any free-swimming green sea turtles observed during transit.
6. Biological monitors will maintain a written log of all green sea turtle observations during project operations. This observation log will be provided to the USACE and NMFS as an attachment to the post-construction report for the project. Each observation log will contain the following information:
• Observer name and title;
• Type of construction activity (maintenance dredging, etc.); • Date and time animal first observed (for each observation); • Date and time observation ended (for each observation). A green sea turtle observation will terminate if (1) an animal is observed exiting the monitoring zone or (2) after a 15-minute period of no observation (assumption is that animal has exited, but was not observed to do so);
• Location of monitor (latitude/longitude), direction of green sea turtle in relation to the monitor, and estimated distance (in meters) of green sea turtle to the monitor; and
• Nature and duration of equipment shutdown.
7. Any observations involving the potential “take” of green sea turtles will be reported to the USACE within 10 minutes of the incident and to the NMFS stranding coordinator immediately thereafter.
8. The Contractor will implement an Environmental Protection Plan that will include a green sea turtle Monitoring and Avoidance Plan and an employee training program on green sea turtle observation protocols, avoidance, and minimization measures. The program will be conducted by the Biological Monitor and a record kept of dates of training, names and positions of attending employees, and an outline of the training presentation.
11 The USACE would also implement the rocky reef/surfgrass monitoring, mitigation, and reporting plan (MMRP) described in Appendix B of the EIS/EIR. The USACE confirmed that the monitoring and analytical methods used would be adequate to identify and accurately measure impacts from the beach nourishment effort. The final MMRP would ensure that appropriate mitigation sites are available to address potential impacts and that the success criteria and analytical methods used are adequate to demonstrate a difference between impact/mitigation sites and control sites. In order to supplement the pre-construction survey and monitoring efforts conducted between 2018 and 2020, the USACE has proposed to conduct additional monitoring in the pre-construction phase to address identified nearshore data gaps. However, the USACE has not provided any written details regarding the proposed additional monitoring.
Based upon the monitoring and mitigation plan described in the EIS/EIR, shallow subtidal surfgrass beds and rocky reefs in the vicinity of San Clemente Beach sediment placement site shall be monitored to determine whether the Project adversely affects shallow subtidal reefs and surfgrass. Underwater transects shall be established offshore and downcoast from the proposed receiver beach. Control transects also shall be established upcoast of the project area. The transects shall be monitored by qualified biologists before and after the proposed action to determine whether the beach fill results in a long-term loss of surfgrass and/or reef habitat. If adverse significant impacts to surfgrass and/or reef habitat compared to controls and baseline conditions are observed from the monitoring, subsequent nourishment activities will be modified to avoid or minimize these impacts as part of adaptive management. If adverse significant impacts still are observed after all reasonable attempts to avoid or minimize impacts have been exhausted, additional renourishment would not occur until impacted surfgrass has recovered or compensatory mitigation is completed. Compensatory mitigation will consist of the creation of shallow rocky habitat in the Project area at a site to be determined in consultation with NMFS and CDFW. Rocky reef habitat will be created in the Project area at a ratio of 1 acre of rocky reef habitat created for 1 acre of rocky reef habitat buried. If the monitoring determines that surfgrass has been affected by the Project, an experimental surfgrass restoration will be implemented.
We considered, under the ESA, whether or not the proposed action would cause any other activities and determined that it would not.
2. ENDANGERED SPECIES ACT:
BIOLOGICAL OPINION AND INCIDENTAL TAKE STATEMENT
The ESA establishes a national program for conserving threatened and endangered species of fish, wildlife, plants, and the habitat upon which they depend. As required by section 7(a)(2) of the ESA, each Federal agency must ensure that its actions are not likely to jeopardize the continued existence of endangered or threatened species or to adversely modify or destroy their designated critical habitat. Per the requirements of the ESA, Federal action agencies consult with NMFS, and section 7(b)(3) requires that, at the conclusion of consultation, NMFS provide an 12 opinion stating how the agency’s actions would affect listed species and their critical habitats. If incidental take is reasonably certain to occur, section 7(b)(4) requires NMFS to provide an ITS that specifies the impact of any incidental taking and includes reasonable and prudent measures (RPMs) and terms and conditions to minimize such impacts.
1. Analytical Approach
This biological opinion includes a jeopardy analysis, but no adverse modification analysis. The jeopardy analysis relies upon the regulatory definition of “jeopardize the continued existence of” a listed species, which is “to engage in an action that reasonably would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species” (50 CFR 402.02). Therefore, the jeopardy analysis considers both survival and recovery of the species. No critical habitat has been designated for Eastern Pacific DPS green sea turtles, therefore critical habitat and the “adverse modification” standard are not considered in this biological opinion
The ESA Section 7 implementing regulations define effects of the action using the term “consequences” (50 CFR 402.02). As explained in the preamble to the final rule revising the definition and adding this term (84 FR 44976, 44977; August 27, 2019), that revision does not change the scope of our analysis, and in this opinion we use the terms “effects” and “consequences” interchangeably.
We use the following approach to determine whether a proposed action is likely to jeopardize listed species:
Evaluate the range wide status of the species expected to be adversely affected by the proposed action.
Evaluate the environmental baseline of the species.
Evaluate the effects of the proposed action on species using an exposure–response approach.
Evaluate cumulative effects.
In the integration and synthesis, add the effects of the action and cumulative effects to the environmental baseline, and, in light of the status of the species, analyze whether the proposed action is likely to directly or indirectly reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species. If necessary, suggest a reasonable and prudent alternative to the proposed action.
In this biological opinion, we specifically evaluate the risks of direct contact injuries for ESAlisted green sea turtles, as well as potential impacts of disturbance, associated with the proposed action. In addition, we consider the adverse effects of harassment of ESA-listed green sea turtles as a result of the proposed action. Consistent with the "Interim Guidance on the Endangered 13 Species Act Term 'Harass’” (NMFS 2016a), we interpret harass in a manner similar to the USFWS regulatory definition for non-captive wildlife:
"Create the likelihood of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns which include, but are not limited to, breeding, feeding, or sheltering."
Under this “Interim Guidance” we interpret the phrase "significantly disrupt normal behavioral patterns" to mean a change in the animal's behavior (breeding, feeding, sheltering, resting, migrating, etc.) that could reasonably be expected, alone or in concert with other factors, to create or increase the risk of injury to an ESA-listed animal when added to the condition of the exposed animal before the disruption occurred. An injury in the context of analyzing behavioral responses could be a physical injury or a physiological or other impact that would reasonably be expected to negatively affect the animal's growth, health, reproductive success, and/or ability to survive (i.e., an effect that results from a more than inconsequential behavioral response).
Harassment does not require that an injury actually result or is proven; only that the behavioral response creates or increases the likelihood of injury.
2. Rangewide Status of the Species
This biological opinion examines the status of the East Pacific Distinct Population Segment of green sea turtle that is likely to be adversely affected by the proposed action. The status is determined by the level of extinction risk that the listed species face, based on parameters considered in documents such as recovery plans, status reviews, and listing decisions. This informs the description of the species’ likelihood of both survival and recovery. The species status section also helps to inform the description of the species’ “reproduction, numbers, or distribution” for the jeopardy analysis.
In 2016, NMFS finalized new listings for 11 green sea turtle DPSs, including listing the East Pacific DPS as threatened (81 FR 20057). The East Pacific DPS includes turtles that nest on the coast of Mexico which were historically listed under the ESA as endangered. All of the green turtles DPSs were listed as threatened, with the exception of the Central South Pacific DPS, Central West Pacific DPS, and the Mediterranean DPS which were listed as endangered Seminoff et al. 2015).1 Recently the IUCN assessed the East Pacific “regional management unit of green sea turtles as “vulnerable,” which was downlisted from a previous “endangered” status (IUCN 2021). Currently, NMFS and USWFS are considering designating critical habitat for the East Pacific green sea turtle DPS as well as several other (five) DPSs within U.S. jurisdiction.
Based on a settlement agreement with several non-profit organizations, the agencies shall propose a determination concerning the designation of critical habitat on or before June 30, 2023.
1 The 2015 biological status report that was used to support the recent listing activities (Seminoff et al. 2015) can be found at: http://www.nmfs.noaa.gov/pr/species/Status%20Reviews/green_turtle_sr_2015.pdf 14 Green turtles are found throughout the world, occurring primarily in tropical, and to a lesser extent, subtropical and temperate waters. The species occurs in five major regions: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Caribbean Sea, and Mediterranean Sea. Molecular genetic techniques have helped researchers gain insight into the distribution and ecology of migrating and nesting green turtles. Throughout the Pacific, nesting assemblages group into two distinct regional areas: 1) western Pacific and South Pacific islands, and 2) eastern Pacific and central Pacific, including the rookery at French Frigate Shoals, Hawaii. In the eastern Pacific, greens forage coastally from the U.S. West Coast (42°N) in the north, offshore in waters up to 1,000 miles from the coast and south to central Chile (40°S). The northern and southern boundaries of this DPS extend from the aforementioned locations in the U.S. and Chile to 143°W and 96°W, respectively (Seminoff et al. 2015). Green turtles found in the Gulf of California originate primarily from the Michoacán nesting stock. Green turtles foraging in southern California and along the Pacific coast of Baja California originate primarily from rookeries of the Islas Revillagigedos (Dutton 2003) and within the state of Michoacán (Dutton et al. 2019). Green sea turtles in the east Pacific are migratory as adults, conducting reproductive migrations every three years on average between their natal nesting sites and foraging areas. Individuals show fidelity to foraging areas, often returning to the same areas after successive nesting seasons. In neritic foraging areas, green turtles in the eastern Pacific are omnivorous, consuming marine algae, seagrass, mangrove parts and invertebrates. Green turtles in the wild are estimated to attain maturity at 15-50 years (Avens and Snover 2013), with East Pacific green turtles averaging 30 years to maturity.
Population Status and Trends: NMFS and USFWS (2007) provided population estimates and trend status for 46 green turtle nesting beaches around the world. Of these, twelve sites had increasing populations (based upon an increase in the number of nests over 20 or more years ago), four sites had decreasing populations, and ten sites were considered stable. For twenty sites there are insufficient data to make a trend determination or the most recently available information is too old (15 years or older). A complete review of the most current information on green sea turtles is available in the 2015 Status Review (Seminoff et al. 2015). The most recent IUCN assessment of the east Pacific population of green turtles was conducted in 2021 (Seminoff and Glass 2020).
Green turtles that may be found within the action area likely originate from the eastern Pacific Ocean area, and based on genetic analyses and satellite tracking of sea turtles foraging in San Diego Bay, likely originate from nesting sites in the Revillagigedo Archipelago and the coast of Michoacán, Mexico (Dutton et al. 2019). Green turtles in the eastern Pacific were historically considered one of the most depleted populations of green turtles in the world. The primary green turtle nesting grounds in the eastern Pacific are located in Michoacán, Mexico (Colola Beach (~74.4 percent of nesting in the state) and Maruata (24.1 percent of nesting in the state), and the Galapagos Islands, Ecuador (NMFS and USFWS 1998) which comprise approximately 71 percent of all nesting females, and linkages between these nesting sites and foraging areas from northwestern Mexico to Peru have been established via flipper tag recoveries and satellite 15 telemetry (Seminoff and Glass 2020). Here, green turtles were widespread and abundant prior to commercial exploitation and uncontrolled subsistence harvest of nesters and eggs. Sporadic nesting occurs on the Pacific coast of Costa Rica. While shallow genetic substructure has been observed in East Pacific green turtles, manifesting as slight morphological differences, Dutton et al. (2014) suggest that green turtles from the Revillagigedos Archipelago are rooted in the broad eastern Pacific genetic clade.
Information has been suggesting steady increasing in nesting at the primary nesting sites in Michoacan, Mexico (Colola Beach), and in the Galapagos Islands since the 1990s (Delgado and Nichols 2005; Senko et al. 2011), although at some of these sites, they are still lower than past annual number of deposited clutches. Colola Beach is the most important green turtle nesting area in the eastern Pacific; it accounts for 75 percent of total nesting in Michoacán and has the longest time series of monitoring data since 1981. Nesting trends at Colola (25,008 clutches/year based on data from 2015-2018) is 52 percent less than the past three generations ago (early 1980s; 51,781 clutches per year), while at Galapagos, albeit a smaller population, the mean annual number of deposited clutches increased by 70 percent (from 3,082 to 5,233 clutches per year) since the late 1970s to early 1980s (Seminoff and Glass 2020).
As mentioned above, most green turtles found off the U.S. West Coast and in the action area likely originate from the Revillagigedos Archipelago and the coast of Michoacán, Mexico. The most recent survey (2008) from Revillagigedos estimated that as many as 500 nests were laid over a 4-week period, which the most recent status review (Seminoff et al. 2015) used to estimate nester abundance at 500 females.
Green sea turtle nesting in the eastern Pacific has increased steadily since the early 1980s, which is likely due to increased protection at nesting beaches, minimized threats to sea turtles in foraging areas, and advances in sea turtle fisheries bycatch reduction throughout the region.
Seminoff et al. (2015) estimated the total abundance of mature females in the East Pacific DPS to be at least 20,062 females.
Three resident foraging populations of green turtles have been observed in nearshore waters adjacent to the proposed action area. South San Diego Bay serves as important habitat for a resident population of approximately 60 juvenile and adult green turtles (Eguchi et al. 2010).
There is also an aggregation of green sea turtles that is persistent in the San Gabriel River and surrounding coastal areas in the vicinity of Long Beach, California as well as in Seal Beach, California (Lawson et al. 2011; Crear et al.2016; Crear et al. 2017). Seasonal shifts in movement and distribution of green turtles in the Long Beach/Seal Beach area show that green turtles in the San Gabriel River use warm effluent from two power plants as a thermal refuge, although the river sustains juveniles and adults year-round (Crear et al. 2016). More recently, Hanna et al. (2021) have documented a small resident foraging population at La Jolla Shores.
A stable isotope study on 718 green turtles foraging at 16 areas (including off the coast of California) indicate that turtles of this DPS are omnivorous (Seminoff et al. 2021). Another 16 stable isotope study indicates that East Pacific green turtles in San Diego Bay forage on invertebrates (50 percent), seagrass (26 percent), and to a lesser extent red and green algae (Lemons et al. 2011). These data are consistent with studies of East Pacific green turtles outside of U.S. jurisdiction (e.g., waters of Mexico, Colombia, and Galapagos Islands) that also demonstrate omnivorous diets (Seminoff et al. 2002; López-Mendilaharsu et al. 2005; Amorocho and Reina 2007; Carrión-Cortez et al. 2010). A study of green sea turtle diet to the south along the Pacific Coast of Baja California, Mexico, indicate that surfgrass was the most prevalent source of forage for green sea turtles in those coastal waters (Lopez-Mendilaharsu et al. 2005). Green turtles in the San Gabriel River forage on algae and invertebrates that attach to rocky bottoms and hard man-made structures (Crear et al. 2017). The main prey item consumed by turtles at the La Jolla Shores location was a filamentous species of Rhodophyta, red algae (Hanna et al. 2021).
Threats: A thorough discussion of threats to green turtles worldwide can be found in the most recent status review (Seminoff et al. 2015). Major threats include: coastal development and loss of nesting and foraging habitat; incidental capture by fisheries; and the harvest of eggs, subadults and adults. Climate change is also emerging as a critical issue. Destruction, alteration, and/or degradation of nesting and near shore foraging habitat is occurring throughout the range of green turtles. These problems are particularly acute in areas with substantial or growing coastal development, beach armoring, beachfront lighting, and recreational use of beaches. In addition to damage to the nesting beaches, pollution and impacts to foraging habitat is a concern.
Pollution run-off can degrade sea grass beds that are the primary forage of green turtles. The majority of turtles in coastal areas spend their time at depths less than 5 m below the surface (Schofield et al. 2007; Hazel et al. 2009), and hence are vulnerable to being struck by vessels.
Collisions with boats are known to cause significant numbers of mortality every year (NMFS and USFWS 2007; Seminoff et al. 2015). Marine debris is also a source of concern for green sea turtles especially given their presence in nearshore coastal and estuarine habitats. In southern California, green turtles forage in urbanized environments and therefore are more exposed to anthropogenic contaminants and pollutants. Sea turtles captured in Seal Beach and San Diego Bay in southern California were found to have higher trace metal concentrations (e.g., selenium and cadmium) than green turtles that inhabit non-urbanized areas (Barraza et al. 2019). A related study found that green sea turtles foraging in San Diego Bay had significantly higher total polychlorinated biphenyls (PCBs) than turtles in Seal Beach, and that these non-dioxin-like PCB congeners may be associated with neurotoxicity (Barraza et al. 2020).
The bycatch of green sea turtles, especially in coastal fisheries, is a serious problem in the Pacific because many of the small-scale artisanal gillnet, setnet, and longline coastal fisheries throughout the Pacific are not well regulated. These are the fisheries that are active in areas with the highest densities of green turtles (NMFS and USFWS 2007). In the northern portions of the East Pacific DPS, bycatch in fisheries has been less well-documented. However, along the Baja California Peninsula (Mexico), hundreds of green turtles were reported stranded (suspected bycatch) in Bahia Magdalena (Koch et al. 2006). In Baja California Sur, Mexico, from 2006-2009, smallscale gillnet fisheries caused massive green sea turtle mortality at Laguna San Ignacio, where an 17 estimated 1,000 turtle were captured each year in a fishery targeting guitar fish (Mancini et al. 2012). Bycatch of green turtles has also been reported in Peru and Chile. While the problem persists, innovated bycatch reduction techniques and monitoring approaches have likely reduced bycatch of all sea turtle species. The meat and eggs of green turtles has long been favored throughout much of the world that has interacted with this species. As late as the mid-1970s, upwards of 80,000 eggs were harvested every night during nesting season in Michoacán (Clifton et al. 1982). Even though Mexico has implemented bans on the harvest of all turtle species in its waters and on the beaches, poaching of eggs, females on the beach, and animals in coastal water continues to happen. In some places throughout Mexico and the whole of the eastern Pacific, consumption of green sea turtles remain a part of the cultural fabric and tradition (NMFS and USFWS 2007; Seminoff and Glass 2020).
Like other sea turtle species, increasing temperatures have the potential to skew sex ratios of hatchling and many rookeries are already showing a strong female bias as warmer temperatures in the nest chamber leads to more female hatchlings (Kaska et al. 2006; Chan and Liew 1995).
Increased temperatures also lead to higher levels of embryonic mortality (Matsuzawa et al. 2002). An increase in typhoon frequency and severity, a predicted consequence of climate change (Webster el al. 2005), can cause erosion which leads to high nest failure (Van Houtan and Bass 2007). Rising sea levels can cause repeated inundation of nests and abrupt disruption of ocean currents used for natural dispersion during the green turtle life cycle. Green sea turtles feeding may also be affected by climate change. Seagrasses are a major food source for green sea turtles and may be affected by changing water temperature and salinity (Short and Neckles 1999; Duarte 2002).
Conservation: There have been important conservation initiatives and advances that have benefited East Pacific DPS green turtles. There are indications that wildlife enforcement branches of local and national governments are stepping up their efforts to enforce existing laws, although successes in stemming sea turtle exploitation through legal channels are infrequent. In addition, there are a multitude of non-profit organizations and conservation networks whose efforts are raising awareness about sea turtle conservation. When assessing conservation efforts, we assumed that all conservation efforts would remain in place at their current levels or improve.
Among the notable regional and/or multinational conservation groups and initiatives are the Central American Regional Network for the Conservation of Sea Turtles, Grupo Tortuguero de las Californias (GTC), Permanent Commission of the South Pacific (CPPS), and the InterAmerican Convention for the Protection and Conservation of Sea Turtles (IAC). The Central American Regional Network resulted in the creation of a national sea turtle network in each country of the Central American region, as well as the development of firsthand tools, such as a regional diagnosis, a 10-year strategic plan, a manual of best practices, and regional training and information workshops for people in the region (e.g., Chacon and Arauz 2001). The GTC is a regional network in Mexico that brings together scientists, conservation practitioners, fishers, and local peoples to address sea turtle conservation issues. Perhaps the greatest achievement of this group was the large decrease in green turtle hunting and local consumption throughout 18 northwestern Mexico. The IAC is the world’s only binding international treaty on sea turtle conservation. Signatory nations in the Eastern Pacific include Chile, Peru, Ecuador, Panama, Costa Rica, Honduras, Guatemala, Mexico, and the United States. This treaty endeavors to reduce fisheries bycatch and habitat destruction through a series of binding conservation agreements across these nations. All three of these initiatives work under the principle that benefits and achievements from working in alliance are much higher than those from working alone.
In southern California, NMFS has increased its outreach and education efforts to improve public awareness of the presence of green turtles and to reduce threats to foraging populations, particularly in San Diego Bay, the San Gabriel River and adjacent watershed, as well as estuaries such as Agua Hedionda and Mission Bay. Local threats to green turtles primarily include recreational fishing and vessel strikes, and NMFS has worked with partners to develop educational materials and signs to specifically address those threats.
NMFS and U.S. Fish and Wildlife Service (FWS) developed a recovery plan for U.S. Pacific populations of the East Pacific Green Sea Turtle that describes reasonable actions which are believed to be required to recover and/or protect the species (NMFS and USFWS 1998). One of the six major actions described in the Recovery Plan is to identify and protect primary foraging areas in U.S. jurisdiction. In addition, the Recovery Plan specifically recommends the prevention of degradation or destruction of marine habitats caused by dredging or disposal activities.
Dredging causes mechanical destruction of benthic habitats, increases sedimentation that may damage algae and seagrasses, and disposal of dredged materials smothers existing flora and fauna. Some types of dredging also directly kills turtles.
3. Action Area
“Action area” means all areas to be affected directly or indirectly by the Federal action and not merely the immediate area involved in the action (50 CFR 402.02). The action area for this project includes Oceanside Harbor, the sediment borrow site offshore Oceanside Harbor, the sediment placement and associated equilibrium footprint at the San Clemente disposal site, and the vessel route between the Oceanside Harbor, sediment borrow and disposal sites. Figures 1-3 above illustrate the action area. Figure 4, below also helps illustrate the potential extent of project effects. The sediment equilibrium footprint is where sand that has been placed onto the beach is predicted to ultimately end up and result in some degree of rocky reef sedimentation and/or burial.
4. Environmental Baseline
The “environmental baseline” refers to the condition of the listed species or its designated critical habitat in the action area, without the consequences to the listed species or designated critical habitat caused by the proposed action. The environmental baseline includes the past and present impacts of all Federal, State, or private actions and other human activities in the action area, the 19 anticipated impacts of all proposed Federal projects in the action area that have already undergone formal or early section 7 consultations, and the impact of State or private actions which are contemporaneous with the consultation in process. The consequences to listed species or designated critical habitat from ongoing agency activities or existing agency facilities that are not within the agency’s discretion to modify are part of the environmental baseline (50 CFR 402.02).
Status in the Action Area
As described in the Rangewide Status section, there are at least three known resident green sea turtle populations in Southern California. Foraging resident populations are found in San Diego Bay, La Jolla Cove, and the San Gabriel River/Anaheim Bay wetland complex. The proposed project lies geographically between these three areas of known green sea turtle residence. Green sea turtle adults and benthic-foraging juveniles generally occupy small home ranges that include foraging resources and underwater refugia. However, some individuals move long distances between foraging areas, including one individual tracked from San Diego Bay to a foraging area near Long Beach, California (SWFSC unpublished data 2016). In 2006, a green sea turtle outfitted with a satellite transmitter was tracked and traveled from Long Beach to the San Onofre nuclear power plant. Hanna et al. (2020) documented two green sea turtles leaving the Anaheim Bay area into nearby offshore waters as far south as Dana Point, which is in relative close proximity to the San Clemente sediment placement location.
Green turtle strandings are documented each year along the U.S. West Coast, with most of these strandings occurring in Southern California. Numerous strandings have occurred along the northern San Diego County and Orange County coastlines in the project vicinity. Causes of green turtle strandings in Southern California include power plant entrainment, vessel collisions, fishing interactions, illness, gunshot wounds, and cold stunning. Because not all dead stranded sea turtles are necropsied and causes of death can be difficult to ascertain in many circumstances during the limited evaluations conducted, the causes of the majority of strandings are unspecified or unknown. In the general vicinity of the action area (i.e., Dana Point to Carlsbad), there were a total of 67 green sea turtle strandings (17 dead and 50 alive) reported to NMFS between 1975 and 2021 (NMFS, unpublished stranding data). The largest concentration of stranding observations occurred at the San Onofre Nuclear Generating Station (SONGS) where 43 green sea turtles were entrained over multiple years. Some of these other strandings are from unknown origins, although boat collisions and interactions with recreational fishermen are likely the cause of many of these strandings. Two live green sea turtles were incidentally caught by recreational fishermen off the San Clemente Pier recently; one in 2018, the other in 2020.
In addition to stranding data, NMFS Southwest Fisheries Science Center developed a hotline email address in 2015 for the public to report opportunistic sightings of sea turtles along the West Coast. Forty five green sea turtle sightings have been reported within the general vicinity of the action area. A few sightings have occurred to the south at surfing beaches. In addition, multiple sightings have occurred just to the north at Doheny State Beach and Dana Point. Most 20 of the strandings and sightings occurred during the relatively warm water months, but some also occurred during the winter and spring months. In addition, most occurrences appear to be juveniles or sub-adults.
The action area has not been a subject of directed green sea turtle study as have some other estuarine/nearshore areas in southern California. Given the relatively high number of strandings and sightings in the action area, green sea turtles are, at a minimum, occasionally using the action area to support seasonal foraging forays and resting behavior. It is also possible that a small resident populations may be present in the general vicinity similar to the recently described La Jolla Cove resident population (Hanna et al. 2021). For example, the high number of live strandings at SONGS suggests that green sea turtles were consistently using the area for foraging and/or resting. As observed in San Diego Bay and the San Gabriel River, it is possible the warm water discharge from the power plant previously provided thermal refuge. In addition, there are a variety of rocky reef habitats that support productive algal, seagrass, and invertebrate communities that may serve as high quality foraging resources. Rocky reefs with crevices and/or overhangs may also support resting behavior.
The nearshore marine habitat in the sediment equilibrium footprint at the San Clemente disposal site contains a number of features that may support green sea turtle foraging and/or resting behaviors. The action area contains a variety of rocky habitats that support foraging resources, such as surfgrass, turf algae, macroalgae, and invertebrate communities, and may provide crevices and hard substrate to support resting behavior. Figure 4 is a summary figure provided by the USACE that demonstrates the extent of natural rocky reef habitat in the project vicinity. The light brown areas comprise rocky reef areas within the sediment equilibrium footprint, and the light blue areas are outside the estimated impact footprint. Of the bedrock and cobble substrates,
57.78 acres of those bottom types are within the sediment equilibrium footprint (Howo, personal communication).
The borrow site offshore Oceanside is predominantly soft bottom habitat with limited utility for foraging and resting purposes. However, a relatively small portion of the borrow pit also contains habitat features that may support green sea turtle foraging and/or resting behaviors. Specifically, the borrow site contains artificial reef modules that are part of a larger artificial reef complex established offshore Oceanside. Each reef module was constructed of 10,000 tons of quarry rock arranged over 128 acres in twenty four-modules. Four pairs of modules were constructed along each of three depth contours: shallow (42 ft), mid-depth (57 ft), and deep (72 ft) (Bedford 1993).
The borrow site contains two and a half module pairs along the reef complex’s shallow contour.
A variety of fish, invertebrates, turf algae, and macroalgae were observed on these reef modules.
The relatively high productivity of these reef features and the crevices provided by the threedimensional structure may attract green sea turtles to use this area for foraging and/or resting.
Adjacent to the borrow site is Oceanside Harbor and the Del Mar Boat Basin, which also contains potential foraging and resting habitat. Eelgrass habitat occurs in both of these harbors (Merkel & Associates, Inc. 2023). In addition, the artificial reef structure provided by the jetties 21 and breakwater may support algae and invertebrate foraging resources, and underwater refugia for resting. For example, elsewhere in the U.S., Renaud et al. (1994) found that juvenile green turtles were closely associated with jetty habitat in south Texas and were likely to forage along extensive algal mats that occur there.
Figure 4: Rocky reef and hard bottom benthic habitat offshore San Clemente.
The small foraging population of green sea turtles at La Jolla Cove have been observed foraging and resting in habitat similar to that provided at the San Clemente site. The main prey item consumed by the small resident foraging population at La Jolla Shores was a filamentous species of Rhodophyta, red algae (Hanna et al. 2021), which is also found at the San Clemente site. The action area contains a variety of habitat features that support the foraging resources described above. We would expect that any green sea turtle found in the vicinity of rocky reef habitat supporting surfgrass, algae, and invertebrates would likely take advantage of the foraging opportunity, if available, and it is possible that these habitat features along the stretch of coastline where the Project is proposed to occur may attract green sea turtles to the area or increase the likelihood that turtles remain in the area longer than if simply transiting through.
After consideration of the available stranding and sighting data, as well as the high quality habitat features at the San Clemente site, NMFS believes the likelihood of frequent occurrence by a number of sea turtles in the action area during significant portions of every year throughout the duration of the project is moderately high.
Coastal Development
22 In addition to the threats described above associated with turtle strandings, the following additional threats to green sea turtles and their foraging and resting habitat are known to occur in the action area. The USACE conducts maintenance dredging in Oceanside Harbor to support safe commercial, recreational, and military navigation operations. Construction occurs annually each spring, and involves dredging up to approximately 500,000 cubic yards. Dredging and disposal operations have the potential to result in direct interactions with turtles and/or modify green sea turtle foraging and/or resting behavior. City of San Clemente was previously issued a regional general permit for opportunistic beach nourishment activities at the Project sediment disposal location, but it was used only twice. In June 2005, approximately 5,000 cy of sediment was placed in the Project vicinity; and in November 2016, approximately 12,000 cy of sediment was placed in the Project vicinity. Sedimentation associated with beach nourishment has the potential to modify green sea turtle foraging and/or resting behaviors associated with adjacent rocky reef habitat. Military operations in the offshore environment between Oceanside and San Clemente have the potential to result in direct turtle interactions due to the various vessel operations associated with military exercises. In addition, immediately adjacent to Oceanside Harbor, various marina and dock related projects have occurred at the Del Mar Boat Basin. Some projects have resulted in adverse impacts to eelgrass habitat necessitating eelgrass mitigation in the area. These activities have the potential to modify green sea turtle foraging and/or resting behaviors. In addition, a significant artificial reef associated with SONGS’s mitigation obligations occurs immediately offshore the action area. Phase 3 of the SONGS project was completed in 2020, which increased the artificial reef to 373 acres of low relief reef with ~45% cover of rock (UCSB 2023). The SONGS artificial reef contains moderately high quality foraging and resting features similar to natural rocky reef habitat.
Climate Change
Increased storm intensity and frequency may increase the rate of disturbance to surfgrass, algae, and invertebrate communities that typically inhabit shallow nearshore rocky reef habitat, which may reduce the quality of foraging resources for green sea turtles throughout their range, including in and around the action area. In addition, increasing ocean temperatures may increase the frequency and duration of green sea turtles in the action area. Green sea turtles are dependent on the ambient ocean temperature to support physiological processes such as digestion and growth (Avery et al., 1993). As sea temperatures increase, we anticipate the thermal properties of the action area to allow for greater foraging access and use, and may allow for higher growth rates, as observed elsewhere in thermal refuges found in southern California (e.g., Eguchi et al., 2012). Increased use of the area may increase the risk of exposure to harmful interactions with dredging operations.
5. Effects of the Action
Under the ESA, “effects of the action” are all consequences to listed species or critical habitat that are caused by the proposed action, including the consequences of other activities that are caused by the proposed action (see 50 CFR 402.02). A consequence is caused by the proposed 23 action if it would not occur but for the proposed action and it is reasonably certain to occur.
Effects of the action may occur later in time and may include consequences occurring outside the immediate area involved in the action (see 50 CFR 402.17). In our analysis, which describes the effects of the proposed action, we considered the factors set forth in 50 CFR 402.17(a) and (b).
Approach to the Effects Analysis
NMFS determines the effects of the action using a sequence of steps. In this analysis, the first step identifies stressors (or benefits) associated with the proposed action with regard to listed species. The second step identities the magnitude of stressors (e.g., duration, extent, and frequency of the stressor and how many individuals of a listed species will be exposed to the stressors; exposure analysis). The third step describes how the exposed individuals are likely to respond to these stressors (e.g., behavioral changes or the injury or mortality rate of exposed individuals; response analysis). The final step in determining the effect of the action is establishing the risks those responses pose to listed species (risk analysis). In this step of our analysis, we will relate information on the number and age (or life stage), if applicable, of the individuals likely to be exposed to the proposed action's effects, along with the likely responses of those individuals to the proposed action, to an expected impact on the populations or subpopulations those individuals represent.
5.5.1. Exposure and Response
The information presented above in Section 2.4 Environmental Baseline: Status in the Action Area suggests that green sea turtle occurrence in the action area is likely. Given the limited amount of scientific study of green sea turtle abundance and distribution in the area, we do not have a specific estimate for the number of turtles that may reside within or occasionally visit the action area. Although occurrence may be relatively less likely or frequent during the early spring and winter months when water temperatures are coldest, NMFS has reasonable certainty that green sea turtles could occur within the action area at any time during the year, and the likelihood of frequent occurrence by a number of sea turtles in the action area during significant portions of every year throughout the duration of the project is moderately high. As a result, the effects analysis herein considers the significance of the action area for green sea turtles throughout the entire year, and assumes that presence will occur in varying degrees throughout the year, and during all of the proposed project activities.
Potential effects to green sea turtles from the proposed project would include: (1) direct contact injury associated with dredging, in-water construction, and vessel support operations; (2) general construction disturbance; and (3) impacts to foraging and resting habitat resulting from alteration or disturbance of benthic habitats from sediment disposal activities. Below we describe the exposure of green sea turtles to general construction activity disturbances, direct contact with construction activities, and changes to foraging habitats and the resulting responses of exposed sea turtles to those consequences of the proposed action. 24 Direct Contact Injury
Dredges, particularly hopper dredges, have the potential to exert significant injuries to sea turtles if they interact during dredging operations. Green sea turtles can become entrained in hopper dredges as the draghead moves along the bottom. Entrainment occurs when turtles cannot escape from the suction of the dredge and they are sucked into the dredge draghead, pumped through the intake pipe, and then killed as they cycle through the centrifugal pump and into the hopper (NMFS 2020). Because entrainment is believed to occur primarily while the draghead is operating on the bottom, it is likely that only those species feeding or resting on or near the bottom would be vulnerable to entrainment. They can also be entrained if suction is created in the draghead by current flow while the device is being placed or removed, or if the dredge is operating on an uneven or rocky substrate and rises off the bottom. Hopper dredge encounters with sea turtles are known to occur in the Southeastern U.S. and have been formally consulted upon numerous times by USACE and NMFS (NMFS 2020). Trailing suction hopper dredge operations in the Atlantic and Gulf of Mexico regions have resulted in more than 112 green sea turtle incidental take occurrences between 1995 and 2017 (Ramirez et al. 2017). In 2012, a dead green sea turtle was found near Encinitas in northern San Diego County with injuries consistent with contact from a hopper dredge (Harris 2014). NMFS understands that dredging activities coincident with the Regional Beach Sand Project Phase 2 permitted by the USACE were occurring in the vicinity of Encinitas during that time period, although that project was much larger in geographic scope.
The borrow site offshore Oceanside is predominantly soft bottom habitat with limited habitat value to support foraging and resting behaviors. Thus, NMFS green sea turtle use of that area may not be as frequent as other more preferred habitats in this region. However, a relatively small portion of the borrow pit also contains a few small artificial reef mounds that may support green sea turtle foraging and/or resting behaviors. Although there has been no directed study of green sea turtle distribution and movements within the action area, NMFS believes it is unlikely that green sea turtles routinely utilize the artificial reef modules within the sediment borrow pit given that they are relatively isolated from other significant areas of rocky reef habitat that likely provide more attractive and higher quality foraging and resting support. However, it is possible that occasional visits associated with coastal foraging and/or migratory turtles could occur. If turtles were to utilize the artificial reef modules for occasional foraging and/or resting purposes, the USACE’s proposed avoidance of the immediate area by establishing an operational 300 foot buffer zone should help minimize the risk of entrainment or direct contact injury.
The Project includes monitoring and avoidance measures, which should reduce the likelihood of a harmful dredging interaction. However, visual monitoring methods may be limited during nighttime operations and/or heightened sea state. Green turtle dive duration may exceed 60 minutes, and green turtles only require two to three seconds to empty and refill their lungs.
During winter months and/or cold water periods, the dive duration typically increases (Madrak et al. 2022). Given the potential brief time period at the surface, prolonged submergence time underwater, and the relatively small visual target provided by a surfacing turtle head, visual 25 monitoring methods may fail to detect green sea turtles in the action area during dredging operations.
Although we do not have an extensive record of mortality and/or injury associated with hopper dredges in southern California, we cannot discount the possibility of such an occurrence given the known presence of turtles in the action area, a previously documented stranding described as consistent with a harmful dredging interaction that was coincident with a similar project in northern San Diego County, and the 50 year time horizon of the Project. Each nourishment event involves dredging approximately 250,000 cy of sediment with 42 days of construction. Thus, green sea turtles in the action area would only be exposed to the risks of dredging interaction during a relatively brief period of time within the year. Therefore, NMFS does not believe the Project would necessarily result in multiple mortalities or injuries associated with the dredging operations. Based upon green sea turtle incidental take information associated with hopper dredging in the Southeast from 2014 through 2018, approximately one turtle was entrained for approximately every 2.7 million cys of dredged sediment (NMFS 2020). The Project anticipates dredging approximately 2.75 million cys over the course of 50 years. Although the data from the Southeast is not directly applicable to southern California given significantly more turtles in the Atlantic and Gulf of Mexico region, it provides some context to estimate entrainment risk to green sea turtles during dredging over the entire 50-year life of this proposed action. Given the available information, we conclude that one harmful green sea turtle interaction that could lead to a significant injury or mortality may occur during the course of this proposed action.
The Project also has the potential to result in direct contact injuries associated with vessel collisions. As described in the Environmental Baseline (section 2.4), vessel collisions are one of the most common sources of injury to sea turtles in southern California. However, the risks of direct contact injury for green sea turtles as a result of Project vessel operations is low given that most project vessels will limit their speed to inside wake zone speeds. The hopper dredge will move at more moderate speeds, up to 13 knots when unloaded. Given the benthic behavioral tendency of green sea turtles and the relatively deep water over which the hopper dredge will be transiting, we do not anticipate a high risk of collision. In addition, a green sea turtle monitor will be onboard the hopper during transit to and from the Oceanside Borrow Site to communicate if there is a need to cease or alter operations to avoid a collision with an observed turtle. The only additional in-water construction equipment associated with beach nourishment is the monobuoy and associated floating section of pipeline extending 1,500 feet to the shoreline at the San Clemente sediment disposal location. As this equipment will be stationary and floating, it is extremely unlikely that any measurable direct contact injury could result from these Project components.
Lastly, the Project has the potential to result in direct contact injuries associated with creation of shallow rocky reef as compensatory mitigation for any burial and/or adverse sedimentation effects. Although no detailed information was provided regarding reef construction, we assume the USACE would utilize a barge capable of transporting and placing reef construction materials (e.g., quarry rock, reef modules) and any necessary support vessels. Such vessel operations 26 typically operate as low enough speeds to avoid risk of direct contact injury. If green sea turtles were resting on the seafloor at the time of rock placement, turtles could be crushed or injured by the falling rock. However, NMFS believes such an occurrence to be extremely unlikely given the noise and disturbance associated with barge operations and anchoring. In addition, reef placement would occur in soft bottom areas that would be less likely to support resting turtles.
We anticipate that turtles would avoid the reef placement area once the construction disturbance commences.
General construction disturbance
In general, all in-water construction projects present some risk of disturbance to any green sea turtles that may be present in the action area. In particular, proposed project activities that may involve the generation of loud underwater sounds have the potential to create disturbance for any green sea turtles in the vicinity. We expect that any individual turtles in the action area will generally attempt to avoid the immediate area where in-water construction noise is occurring.
Avoidance of the immediate project area for relatively short periods of time during the 4 month construction window is not likely to be significant, given the relatively limited spatial scope of in-water construction work compared to available habitat elsewhere in the action area. Although renourishment events will introduce similar temporary disturbances in the future, they do not pose a cumulative effect of concern given the approximate 6 year time interval between events.
If reef placement were to occur as compensatory mitigation, we assume that construction window would be similar or less. Therefore, we expect avoidance of the project area due to reef placement is also not likely to be significant.
Impacts to foraging and resting habitat
Sediment from the beach fill project will be redistributed by wave and tidal energy onto nearshore areas, which may bury rocky reef habitat, surfgrass, algae, and benthic invertebrates that support green sea turtle foraging and resting behavior. Sediment is expected to persist within the equilibration footprint for 6 years. The burial impacts will decrease as the fill naturally erodes, which will begin after equilibration is reached. At the end of approximately 6 years, the beach and nearshore profiles are expected to return to existing conditions, which triggers a renourishment event that begins another cycle of burial and/or sedimentation impacts.
Based upon information provided by the USACE, anticipated impacts to nearshore rocky reef habitat cannot be quantified with high temporal or spatial certainty due to modeling constraints.
In their previous 2012 response, the USACE estimated one acre of reef burial as a reasonable worst-case scenario, and they used that impact estimate to calculate contingency costs for compensatory mitigation. However, this estimate was based on the assumption that there was only five acres of rocky reef in the sediment equilibrium footprint. Based upon acoustic surveys conducted in 2018, approximately 58 acres of rocky reef habitat (i.e., bedrock and cobble substrate) occurs within the sediment equilibrium footprint (Nearshore and Wetland Surveys 2018; Howo, personal communication). An updated quantitative impact assessment was not 27 provided by the USACE and the previous environmental documentation did not clearly explain how the USACE determined one acre of reef burial was the worst case estimate. The USACE’s original worst case burial estimate is equivalent to 20% of the reef area previously assumed to occur within the sediment equilibrium footprint. In the absence of a more sophisticated sediment transport modeling analysis, NMFS assumes the worst case burial estimate is proportional to the area of reef subject to sedimentation within the equilibrium footprint. Thus, NMFS assumes that up to 11.6 acres (20% of 58 acres) of rocky reef may be adversely affected through sedimentation and burial effects. Sediment may eventually be redistributed by waves and currents outside the sediment equilibrium footprint allowing for some level of recovery, but the renourishment events may subsequently result in similar levels of burial resulting in a persistent cycle of habitat degradation over the course of the proposed action.
As mentioned above, green sea turtles are known to occur and transit within the action area, and may be found in the project area at any time during the year and take advantage of the available foraging and resting habitat in the project area, although NMFS anticipates reduced activity and/or presence during cold water periods. Rocky reef sedimentation and burial would likely reduce the quantity and quality of algae, invertebrates, and surfgrass, which would decrease the availability of foraging resources in the impact footprint. Sedimentation may also reduce the size and/or availability of reef crevices and overhangs that could support resting behavior. This reduction in the quantity and/or quality of rocky reef and associated biological communities would likely disrupt foraging and/or resting behaviors. Although the duration of sedimentation effects is uncertain, the project has a 50 year life span with multiple renourishment events. Based upon the above, NMFS concludes there will be persistent rocky reef habitat degradation and loss of potential green sea turtle foraging habitat as a result of the proposed project. Therefore, NMFS assumes the effects to foraging and resting behaviors would persist throughout the life of the project.
Although disruption of normal behaviors and movements for green turtles in and around the vicinity of the project area is relatively straightforward to anticipate based on the project description and our general understanding of green turtle behavior, it is very difficult to quantify the impacts of this disruption on the health of individual green turtles. A search of the scientific literature suggests that virtually no directed studies of sea turtle health effects resulting from behavior disruption have been conducted, so we do not have available scientific information to directly point to for this analysis. Instead, we must rely upon general biological and ecological principles to understand what the results of these impacts could be. Conceptually, we recognize that disruptions of important functions and behavior such as regular foraging and resting patterns can have adverse effects on the health of individual sea turtles. Possible adverse effects could include increased energy expenditures, reduced nutritional intake, temporary disorientation, or temporary abandonment of preferred habitat. It is possible that disruption could influence behavior patterns such that some individuals may discover or develop new areas of preferred habitat in other locations. Unfortunately, we also do not have any direct scientific information available to inform establishment of any thresholds for exactly how long or intense the disruptions have to be in order to produce some measurable reduction in overall health or fitness. 28 Currently, general characterizations of the health of individual sea turtles are not understood beyond obvious physical appearance without sophisticated veterinary examinations or laboratory analysis, typically conducted only on deceased individuals. The scale of possible impacts occasional, sustained, or multiple disruptions of normal behavior and life functions over extensive periods could have on the near-term health or fitness of a green turtle is expected to be highly variable and unique to each individual. In other analyses of potential impacts from coastal development projects, disruptions of behavioral patterns in those instances generally would have occurred in areas away from where NMFS expects green turtles typically spend significant portions of their time. Therefore, potential disruptions of behaviors for any period of time in those areas was not likely to significantly impact or disrupt their regular foraging movement and behavior patterns. This expectation supported conclusions that any regular or sustained disruptions of behavior in those areas was unlikely to have any detectable effect on health.
However, for this proposed action we cannot reach the same conclusions. The proposed project occurs in an area where multiple individuals of the species are expected to spend time foraging, resting, and/or migrating. We expect potential sedimentation effects will result in persistent changes to important biological and physical features that support normal foraging and resting behaviors. Therefore, we conclude the project will likely result in adverse effects through a significant disruption of normal behavior patterns that creates the likelihood of injury to the exposed individuals.
2 The USACE has committed to implementing a rocky reef and surfgrass monitoring and mitigation plan to address sedimentation effects on nearshore reef communities. The USACE confirmed that the monitoring and analytical methods used would be adequate to identify and accurately measure impacts from the beach nourishment effort, and their final monitoring and mitigation reporting plan would ensure that appropriate mitigation sites are available to address potential impacts and that the success criteria and analytical methods used are adequate to demonstrate a difference between impact/mitigation sites and control sites. If adverse effects occur to rocky reef and/or surfgrass habitat, the USACE would create shallow rocky habitat in the Project area at a ratio of 1 acre of rocky reef habitat created for 1 acre of rocky reef habitat buried. If the monitoring determines that surfgrass has been affected by the Project, an experimental surfgrass restoration would be implemented. However, a final detailed mitigation plan and associated construction approach was not provided by the USACE. Therefore, it is uncertain to what extent the USACE’s compensatory mitigation approach would specifically benefit green sea turtles. Although the beneficial effects of the compensatory mitigation are difficult to describe given the limited information provided by the USACE, NMFS does not
2 In 2016, NMFS completed formal ESA consultation with the USACE that concluded disturbance from an eelgrass mitigation project that was proposed to be conducted in an area where high concentrations of green sea turtles were expected to occur in South San Diego Bay resulted in “take” in the form of harassment (NMFS 2016b). In 2019, NMFS completed formal ESA consultation with the U.S. Navy that concluded sustained disturbance and disruption of green sea turtle behaviors in and around Anaheim Bay could diminish the health and fitness of individuals for periods throughout the duration of a proposed action (NMFS 2019). 29 anticipate that rocky reef creation and/or surfgrass transplants would likely have any long term adverse effects to green sea turtle foraging and/or resting habitat.
Risk
As described in Section 5.5.1 Exposure and Response, we conclude that direct injury and disruption of normal behaviors resulting from the Project is likely to occur and result in adverse health effects to any individual sea turtles that reside or visit the action area where the proposed dredging and beach nourishment will occur. In particular, exposure to hopper dredging operations during multiple nourishment events over a 50 year time horizon may injure or kill green sea turtles at the sediment borrow site location. In addition, potential disruption of foraging and resting from loss and/or avoidance of rocky reef habitat at the nourishment site is anticipated to occur. The effects to turtles associated with rocky reef sedimentation impacts are uncertain, but disruption of normal foraging and resting patterns can have adverse impacts on the relative health of individuals. The definition of “take” under the ESA includes the term “harass,” but that term is not further defined in the ESA. As described in Section 2.1. Analytical Approach in this biological opinion under our Interim Guidance (NMFS 2016a), we interpret harassment under the ESA to equate to significant disruption of normal behavior patterns (e.g., foraging) that could reasonably be expected, alone or in concert with other factors, to create or increase the risk of negatively affecting an ESA-listed animal's growth, health, reproductive success, and/or ability to survive (i.e., an effect that results from a more than inconsequential behavioral response). For the purposes of this analysis, we conclude that the proposed actions are expected to create or increase the risk of adversely affecting ESA-listed green sea turtles in the action area through significant disruption of normal behaviors patterns associated repeated sedimentation effects that will last throughout the duration of the Project.
In Section 2.4 Environmental Baseline: Status in the Action Area, we reviewed the available information regarding the abundance of green sea turtles in the area. Given the limited amount of scientific study in the area, we do not have a specific estimate for the number of turtles that may reside within or occasionally visit the action area. We assume that all individuals and demographic types that may occur in the action area are equally vulnerable to exposure to the effects of the Project. Although we do not have an extensive record of mortality and/or injury associated with hopper dredges in southern California, we cannot discount the possibility of such an occurrence. As a result, we concluded that up to one green sea turtle may be killed by the proposed action. Assuming a worst case scenario that the killed turtle is a reproductive female, such a loss would only result in a 0.005% reduction (one out of more than 20,000 nesting females) in the current estimated female green sea turtle nesting population of the East Pacific DPS, at most.
We also expect green sea turtles to be disrupted by project sedimentation effects, and/or be forced to move around or away from the project area. We acknowledge that the overall impact of these behavioral disruptions on the growth, health, fitness, or reproduction of an individual sea turtle is very uncertain, and likely to vary by individual. Ultimately, we conclude that the likely 30 responses for at least some exposed individuals would be reflective of adverse effects to health and behavior as a result of harassment due to expected project activities and impacts.
The adverse effects identified are relevant to dredging operations at the sediment borrow site offshore Oceanside Harbor and the beach nourishment site at San Clemente, and may begin as early as fall 2023. Although there are risks of detectable impacts to individuals associated with nearshore rocky reef sedimentation, we do not expect any significant long-term impacts that would result in the actual death or injury of any individual green turtles. The area affected by project activities is relatively small compared to amount of rocky reef and associated biological communities elsewhere in the action area and general vicinity. Based on our general understanding of green sea turtle behavior, we expect turtles may avoid the sediment borrow site area during dredging operations and the affected nearshore reefs at San Clemente, and utilize other parts of the action area, as well as other locations closer to the known resident populations.
While physical or physiological impacts associated with increased stress levels or reduced nutritional intake as a result of disruption in normal behaviors are likely to occur to some degree, we expect these affects to be temporary. Given that the affected reef area is relatively small compared to reef available elsewhere in the general vicinity, we conclude that adequate habitat exists beyond the project area with sufficient carrying capacity to support green sea turtles without any risks of long-term reduction in their overall fitness.
Following the completion of the proposed project, we expect the green sea turtles will adjust and/or resume their normal and preferred behavior and movement patterns within the action area.
Although the short-and-long term impacts of disturbance to sea turtles are not well documented, the available evidence suggests that the anticipated level of disturbance would not trigger significant long-term changes in behavior patterns on a large scale. Regardless of the exact extent of disturbance, avoidance, disruption, or displacement that occurs for any individual turtle during the proposed project, we expect the adverse effects associated with disruptions of important foraging and resting behaviors to be confined within the relatively small action area and duration of project construction and repeated nourishment events. As a result, there should be no detectable long-term impact of the proposed project on green sea turtles beyond disruptions that may occur during the proposed action.
In this opinion, we acknowledged that climate change could influence green sea turtle occurrence and their movement patterns, and the distribution of important habitat features within the action area. NMFS believes the recovering east Pacific green turtle population will likely result in more turtles entering the action area in the future (e.g., Eguchi et al. 2020). In addition, NMFS anticipates that increasing sea surface temperature associated with climate change may increase the frequency and duration of green sea turtle use of nearshore marine areas in southern California. The increasing population and sea surface temperature trends may increase the number of green sea turtles exposed to Project impacts over the life of the proposed action. 31 6. Cumulative Effects
“Cumulative effects” are those effects of future State or private activities, not involving Federal activities, that are reasonably certain to occur within the action area of the Federal action subject to consultation [50 CFR 402.02 and 402.17(a)]. Future Federal actions that are unrelated to the proposed action are not considered in this section because they require separate consultation pursuant to section 7 of the ESA.
Most of the projects that are expected to continue over time require Federal permits (e.g., USACE) or are Federal actions which are expected to be subject to future consultation under the ESA and are therefore not Cumulative Effects. After considering the available information, we have determined that current and continuing non-Federal actions that may continue to occur in the action area and may be affecting green sea turtles in the action area are already addressed in the Environmental Baseline section.
Some continuing non-Federal activities are reasonably certain to contribute to climate effects within the action area. However, it is difficult if not impossible to distinguish between the action area’s future environmental conditions caused by global climate change that are properly part of the environmental baseline vs. cumulative effects. Therefore, all relevant future climate-related environmental conditions in the action area are described earlier in the discussion of environmental baseline (Section 2.4).
7. Integration and Synthesis
The Integration and Synthesis section is the final step in assessing the risk that the proposed action poses to species and critical habitat. In this section, we add the effects of the action (Section 2.5) to the environmental baseline (Section 2.4) and the cumulative effects (Section
2.6), taking into account the status of the species (Section 2.2), to formulate the agency’s biological opinion as to whether the proposed action is likely to: (1) reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing its numbers, reproduction, or distribution; or (2) appreciably diminish the value of designated or proposed critical habitat as a whole for the conservation of the species.
NMFS has determined green sea turtle occurrence in the action area is likely given the relatively high number of stranding and sighting observations, as well as the abundant nearshore rocky reef habitat which likely supports foraging and resting behaviors. However, we do not have a specific estimate for the number of turtles that may reside within or occasionally visit the action area given the lack of scientific study of green sea turtle distribution and abundance in the area. At a minimum, green sea turtles from adjacent resident populations are occasionally using the action area to support foraging forays and resting behavior. It is also possible that a small resident populations may be present in the general vicinity similar to the recently described La Jolla Cove resident population (Hanna et al. 2021).
32 Based on the analysis of potential effects considered in this biological opinion, we determined the Project may result in direct contact injury or death associated with hopper dredging operations. NMFS believes the recovering east Pacific green turtle population will likely result in more turtles entering the action area in the future (e.g., Eguchi et al. 2020). In addition, NMFS anticipates that increasing sea surface temperature associated with climate change may increase the frequency and duration of green sea turtle use of nearshore marine areas in southern California. Given the current understanding of exposure risk and likely increased exposure into the future, we were unable to conclude such effects are discountable, but we do not anticipate multiple occurrences of injury or death. As a result, we assume that up to one green sea turtle mortality may occur, which would be a negligible reduction to the population of East Pacific DPS green sea turtles.
We have also determined that some green sea turtles that may occur in the action area would be incidentally harassed through significant disruption of normal behavior patterns over the duration of the proposed project due to burial and/or sedimentation effects on nearshore rocky reef habitat. We have determined that affected turtles could be of any age or sex in this population.
Although we conclude that some turtles will experience adverse effects from disruption of normal behavior and movement patterns, we have also concluded that there is adequate habitat in the vicinity outside of the impact footprint to support green sea turtles during this time, and that all individual green turtles affected by sedimentation related effects will ultimately survive the disturbance and resume normal behavior and movement patterns outside the localized impact footprint and/or after the project is complete. As a result, we have concluded the effects associated with nearshore reef sedimentation and/or burial are ultimately not likely to have a detectable impact on the reproduction, numbers, or distribution of the foraging population of ESA-listed green sea turtles in the action area or Eastern Pacific DPS green turtle population structure and diversity. Given the expected lack of any significant long-term impacts on the population, we conclude that the proposed action is not likely to produce any detectable reduction in the ability of ESA-listed green sea turtles to adapt or be resilient to climate change in any way.
When considering the effects of the Project to the status, environmental baseline, and cumulative effects of other activities, and the anticipated effects of climate change over the foreseeable future, NMFS anticipates a negligible reduction in the numbers, reproduction, or distribution of green sea turtles and therefore no appreciable reduction in the likelihood of survival and recovery of the East Pacific DPS green sea turtles.
8. Conclusion
After reviewing and analyzing the current status of the listed species, the environmental baseline within the action area, the effects of the proposed action, the effects of other activities caused by the proposed action, and the cumulative effects, it is NMFS’ biological opinion that the proposed action is not likely to jeopardize the continued existence of East Pacific DPS green sea turtles. 33 No critical habitat has been designated or proposed for this species; therefore, none was analyzed.
9. Incidental Take Statement
Section 9 of the ESA and Federal regulations pursuant to section 4(d) of the ESA prohibit the take of endangered and threatened species, respectively, without a special exemption. “Take” is defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to attempt to engage in any such conduct. “Harm” is further defined by regulation to include significant habitat modification or degradation that actually kills or injures fish or wildlife by significantly impairing essential behavioral patterns, including breeding, spawning, rearing, migrating, feeding, or sheltering (50 CFR 222.102). “Harass” is further defined by interim guidance as to “create the likelihood of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns which include, but are not limited to, breeding, feeding, or sheltering.” “Incidental take” is defined by regulation as takings that result from, but are not the purpose of, carrying out an otherwise lawful activity conducted by the Federal agency or applicant (50 CFR 402.02). Section 7(b)(4) and section 7(o)(2) provide that taking that is incidental to an otherwise lawful agency action is not considered to be prohibited taking under the ESA if that action is performed in compliance with the terms and conditions of this ITS.
As described earlier, NMFS has interpreted “harass” to mean creating the likelihood of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns which include, but are not limited to, breeding, feeding, or sheltering."
1. Amount or Extent of Take
In the biological opinion, we described incidental take of green sea turtles residing and/or transiting through the action area through injury or death associated with hopper dredging operations. In addition, we described harassment as a result of disruption of normal foraging and behavior patterns due to the Project. Given the limited amount of scientific study of green sea turtle distribution and abundance in the area, we do not have a specific estimate for the number of turtles that may reside within or occasionally visit the action area. Therefore, it is difficult to quantify the number of turtles that would be exposed to Project effects. We expect that affected individuals comprise an unknown mix of male and female juveniles and adults.
Ultimately, because we were unable to discount the possibility of direct contact injury or death associated with hopper dredging operations based on the available information, we have determined that up to one green turtle is expected to be killed or injured through a harmful interaction with a hopper dredge over the course of the proposed action. If any green sea turtles are observed stranded within the vicinity of the action area at any time during the proposed construction activities, or within 60 days following conclusion of proposed construction, NMFS will evaluate the likely cause of the stranding and the overall health of the individual. Based on those results, we may determine if take will have occurred as a result of the proposed action. If 34 Project monitoring and stranding observations indicate more than one green sea turtle is determined to have received an injury or be killed through direct contact with the proposed action, then take will have occurred in excess of what has been considered in this biological opinion.
Harassment as a result of disruption of normal foraging and behavior patterns may occur through changes in turtle movement, foraging, and resting behaviors due to avoidance of the project area, and reduction in habitat usage of affected nearshore rocky reefs and biological communities. We acknowledge that the overall impact of these behavioral disruptions on the growth, health, fitness, or reproduction of an individual sea turtle is uncertain, and likely to vary by individual.
We expect all of these individuals to survive, and to eventually resume normal patterns and health after the project is completed.
Given the combined uncertainty associated with the number of exposed turtles and the biological effect of the anticipated behavioral disruptions, and because this harassment is expected to occur through the pathways of disturbed and degraded habitats or avoidance of certain areas, we will quantify anticipated incidental take through the use of surrogate indicators of habitat disturbance or avoidance. NMFS expects that up to 11.6 acres of nearshore rocky reef and associated biological communities in the sediment equilibrium footprint, would be adversely affected by sedimentation and/or burial. If the Project results in greater impacts to nearshore rocky reef habitat in the action area, then anticipated incidental take may have been exceeded. NMFS will also evaluate the results of any research conducted on green sea turtles in the area before, during, and after the proposed project that may inform our understanding of effects associated with reduced foraging and/or resting habitat in the action area to determine if take has occurred in excess of what has been considered in this biological opinion.
2. Effect of the Take
In the biological opinion, NMFS determined that the amount or extent of anticipated take, coupled with other effects of the proposed action, is not likely to result in jeopardy to the species.
3. Reasonable and Prudent Measures
“Reasonable and prudent measures” are measures that are necessary or appropriate to minimize the impact of the amount or extent of incidental take (50 CFR 402.02).
1. The USACE shall implement measures to monitor, document, and report all incidental take of green sea turtles resulting from the Project.
2. The USACE shall implement measures to minimize the risk of injury associated with dredging operations, and minimize the extent of disruption of normal foraging and behavior patterns of green sea turtles.
35 4. Terms and Conditions
In order to be exempt from the prohibitions of section 9 of the ESA, the Federal action agency must comply with the following terms and conditions. The USACE has a continuing duty to monitor the impacts of incidental take and must report the progress of the action and its impact on the species as specified in this ITS (50 CFR 402.14). If the entity to whom a term and condition is directed does not comply with the following terms and conditions, protective coverage for the proposed action would likely lapse.
1. The following terms and conditions implement reasonable and prudent measure 1:
1A. Prior to initiating the proposed project, the USACE shall provide NMFS WCR an updated schedule for the anticipated start and completion of project activities of in-water work. The updated schedule shall be provided to Dan Lawson via electronic mail ([email protected]) or the following address:
Dan Lawson, Branch Chief
NMFS West Coast Region Protected Resources Division
7600 Sand Point Way NE, Bldg 1
Seattle WA 98115
1B. The USACE shall monitor the project area as described in section 1.3 and record the presence and behavior of green sea turtles that are observed by project monitors within and around the proposed project. In addition to a monitor onboard the hopper dredge, a qualified biologist or qualified monitor with experience monitoring green sea turtles will be onboard any construction barge used for creating rocky reefs as compensatory mitigation, and will monitor for the presence and behavior of green sea turtles. To the extent possible, biological monitors shall attempt to photograph surfacing sea turtles (typically head photographs) observed in the action area and provide the images to NMFS. The USACE should also summarize all pertinent details regarding the progress and effectiveness of the monitoring and mitigation measures used during the proposed project, along with an assessment of potential impacts that may have occurred as a result of project activities based on what was observed. This information shall be reported to NMFS as outlined in 1C.
1C. Upon completion of each nourishment event and any compensatory mitigation activities, the USACE shall complete a report summarizing all data recorded during all monitoring throughout all phases of the proposed project, including all documentation and summary analysis of the presence and behavior of green sea turtles, effectiveness of the monitoring and avoidance measures, and assessment of any potential impacts that may have occurred throughout the entire proposed action. The summary observation report shall include at least the following information: number(s), estimated size/age class (if applicable), date, locations (latitude and longitude), and behaviors associated with the observations of any ESA-listed species under NMFS jurisdiction (e.g., sea turtles and ESA-listed marine mammals). The report shall be 36 provided to NMFS WCR within 120 days following completion of all project activities by email to [email protected] or the address listed above.
1D. Prior to initiating the proposed project, the USACE shall provide NMFS WCR an updated monitoring plan for minimizing and avoiding the impacts of project activities on sea turtles. This plan should specify the project activity monitoring zone and the response of project activities if protected species are observed in this zone for each type of project activity. The plan should be provided to Dan Lawson at the same email address above. 1E. The USACE shall require project monitors, key contractor and USACE project personnel to attend a project briefing prior to starting work the proposed project. The project briefing shall review the protocols for minimization and avoidance of impacts to sea turtles as described in this biological opinion, as well as review the latest scientific information regarding green sea turtle ecology in the action area.
1F. Prior to initiating the proposed project and in coordination with NMFS WCR, the USACE shall develop and provide NMFS WCR a detailed final monitoring and mitigation reporting plan regarding Project effects on nearshore rocky reef habitat and associated biological communities.
The USACE shall coordinate with Bryant Chesney ([email protected]) prior to final submission. The final plan and any updates shall be provided to Dan Lawson at the email address identified above. The monitoring and mitigation plan shall be developed to address and evaluate:
the accuracy of key assumptions and expectations regarding the anticipated environmental impacts of the proposed action in comparison to any resulting impacts that do occur;
the adequacy of the monitoring and analytical methods to identify and accurately measure impacts from the beach nourishment effort.
physical and biological monitoring of key habitat features throughout the sediment equilibrium footprint, such as the area of bedrock, boulder, cobble, and sand bottom habitat, as well as indicators of habitat quality, such as surfgrass, algae, and invertebrate cover and abundance;
appropriate mitigation sites for rocky reef creation and/or alternative mitigation activities that could enhance the quantity and/or quality of green sea turtle foraging and resting habitat; and
reporting timeline and process for documenting the extent of incidental take of green sea turtles through nearshore reef burial and/or sedimentation. At a minimum, the monitoring plan should report the extent of reef habitat within the sediment equilibrium footprint and quantify any reduction in rocky reef area. In addition, the report shall document any reductions in cover of surfgrass, macroalgae, and sessile invertebrates within the sediment equilibrium footprint. A draft report for each monitoring event shall be provided to NMFS WCR within 60 days following completion of habitat monitoring activities by email to [email protected], with a final report provided within 90 days.
37 1G. Prior to initiation of any future beach renourishment events, the USACE shall develop, in coordination with NMFS WCR, a standardized and consistent protocol for assessing impacts to nearshore rocky reef communities for future events based upon consideration of any deficiencies identified in development of the final monitoring and mitigation reporting plan described in 1F above, information collected from monitoring during the initial nourishment event, and other relevant impact assessment approaches used for similar types of projects. The protocol and any updates shall be provided to Dan Lawson at the same email address listed above. 1H. The USACE shall report any incidents or observations of injuries and/or mortalities of green sea turtles to the NMFS West Coast Region Stranding Coordinator, Justin Viezbicke, at 562-980- 3230 or [email protected], as soon as practicable. In the event an injury or mortality of a green sea turtle occurs at any time during the proposed project, the USACE shall cease any activities that may have resulted in the injury or mortality until such time as they evaluate the cause of the harm and consider application of additional protective measures to address those circumstances, in consultation with NMFS.
2. The following terms and conditions implement reasonable and prudent measure 2:
2A. Hopper dredge requirements
During all hopper dredging operations, a qualified biologist will monitor for the presence of ESA-listed green sea turtles. The dredge operator will maintain a safe working environment for the biological monitor to access and effectively monitor inflow screening, overflow screening, and dragheads for incidental take of ESA-listed green sea turtles after every load.
Draghead observation:
Upon completion of each load cycle, dragheads will be monitored as the draghead is lifted from the seafloor and placed on the saddle in order to ensure that any ESA-listed species that may be impinged within the draghead are observed and accounted for. The qualified biologist, or designated crew member under the guidance and supervision of the qualified biologist when safety is of concern, must physically inspect dragheads for evidence of any ESA-listed green sea turtle interaction after every load.
Inflow screening Observation:
Inflow screening must be designed to capture and retain material for the qualified biologist to monitor for the presence of ESA-listed species. The screened area must be accessible to the biological monitor to ensure 100% observer coverage. The biological monitor must inspect the contents of all inflow screening boxes after every load, including opening the box (where applicable and safely accessible) and looking inside at all contents for evidence of ESA-listed species entrainment. If the contents are not clearly visible and identifiable from a location 38 outside of the box, then in limited instances, the biological monitor may be required to enter the inflow box to identify contents for evidence of ESA-listed species take.
All hopper dredges are required to have 100% inflow screening unless they must be removed for safety due to clogging as outlined below.
Inflow screening size will start at 4-inch by 4-inch, but may be gradually adjusted to a larger screen size if clogging reduces the ability for the qualified biologist to monitor the inflow for the presence of ESA-listed species or if clogging reduces dredging production and thereby expands the time dredging is required. Scenarios that may result in the clogging of inflow and overflow screens are dredge and project specific. All modifications will be made in close coordination with the dredging contractor, qualified biologist, appropriate USACE project managers, and NMFS. The USACE will provide NMFS with a notification when screen sizes are increased or inflow screens are removed that will include an explanation of what attempts were made to reduce the clogging problem, how long the problem may persist, and how effective overflow screening will be achieved.
If inflow screens are increased to be larger than 4-inch by 4-inch or are removed due to clogging, the USACE will continue to re-evaluate the risk of clogging on a load by load basis and the inflow screens will be reinstated when clogging is no longer occurring. The USACE will track the number of loads that inflow screens were removed as part of the reporting requirements.
Hopper dredge operators will not open the hydraulic doors on the inflow boxes prior to inspection by the qualified biologist for evidence of ESA-listed take. If the inflow box cannot be observed due to clogging, the box contents cannot be dumped or flushed unless overflow screening that captures contents for observation by the qualified biologist is operational and monitored for evidence of take. Once overflow screening is operational, the qualified biologist shall also visually monitor box contents as they are dumped or flushed into the hopper.
39 Overflow Screening Observations:
All hopper dredges are recommended to have operational overflow screening and monitor for take after each load. Overflow screening is required to be installed and monitored after each load if the inflow screening is removed or bypassed due to clogging. Overflow screening must be designed to capture and retain material larger than the screen size for the qualified biologist to monitor for the presence of ESA-listed species. The screened area must be accessible to the qualified biologist to inspect for evidence of ESA-listed species take.
Screen size will start at 4-inch by 4-inch, but may be adjusted to a larger screen size if clogging reduces the ability for the qualified biologist to monitor the screen for the presence of ESA-listed species or if clogging reduces dredging production and thereby expands the time dredging is required. All modifications will be made in close coordination with the dredging contractor, qualified biologist, appropriate USACE project managers, and NMFS. If screen sizes are increased due to clogging, the risk of clogging will be re-evaluated weekly and the overflow screens will be reinstated using the smallest screen size that can be effectively used (preferably 4 inch by 4 inch) when clogging is no longer occurring.
2B. To prevent impingement or entrainment of ESA-listed species within the water column, dredging pumps will be disengaged by the operator when the dragheads are not actively dredging and therefore working to keep the draghead firmly on the bottom. Pumps will be disengaged when lowering dragheads to the bottom to start dredging, turning, or lifting dragheads off the bottom at the completion of dredging. Hopper dredges may utilize a bypass or other system that would allow pumps to remain engaged, but result in no suction passing through the draghead. 2C. Pumping water through the dragheads is not allowed while maneuvering or during travel to/from the disposal or pumpout area. The dredge operator will ensure the draghead is embedded in sediment when pumps are operational, to the maximum extent practicable. 2D. If green sea turtles are regularly seen by project monitors in the action area, especially within the vicinity of hopper dredging operations, the USACE shall contact NMFS to discuss implementation of any additional measures to reduce the risks of direct contact injuries or other adverse effects, along with potential modification of the green sea turtle monitoring plan to more specifically evaluate the impacts of the proposed project within this specific area. 40 2E. If the USACE’s final monitoring and mitigation plan indicates that the currently available pre-construction survey information is inadequate to assess impacts to nearshore rocky reef and associated biological communities, and additional pre-construction physical and biological monitoring is not practicable to implement prior to the first nourishment event, then the USACE should utilize acoustic survey techniques similar to that already obtained for pre-construction purposes (i.e., Nearshore and Wetland Surveys 2018) to assess change in area of rocky reef substrate after completion of sediment placement. In this circumstance, any post-construction reductions in reef area that are measured which exceed a statistically reliable estimate of natural variability within the action area should be assumed to be due to the Project, and the USACE should implement rocky reef creation consistent with the associated environmental commitment in the EIS/EIR, or a functionally equivalent mitigation alternative. In addition, in this circumstance the USACE should assume some reduction in quantity and/or quality of surfgrass habitat, and should implement the test surfgrass transplant as planned for in the EIS/EIR. 2F. During any reef construction operations, a qualified biologist will monitor for the presence of ESA-listed green sea turtles. The barge operator will maintain a safe working environment for the qualified biologist. The green sea turtle monitor will identify and communicate if there is a need to cease or alter operations to avoid impacts to green sea turtles. The biologist or monitor will clear the construction area and confirm no green sea turtles are present 30 minutes prior to the startup of reef placement operations. If a green sea turtle is observed within the vicinity of the project site during project operations, all appropriate precautions shall be implemented to avoid or minimize unintended impacts. These precautions include, but are not limited to:
Cessation of operations within 100 feet of an observed green sea turtle; Operations may not resume until the green sea turtle has departed the monitoring zone by its own accord or has not been observed for a 15-minute period of time; and Maneuver the barge to avoid any free-swimming green sea turtles observed during transit.
10. Conservation Recommendations
Section 7(a)(1) of the ESA directs Federal agencies to use their authorities to further the purposes of the ESA by carrying out conservation programs for the benefit of the threatened and endangered species. Specifically, “conservation recommendations” are suggestions regarding discretionary measures to minimize or avoid adverse effects of a proposed action on listed species or critical habitat or regarding the development of information (50 CFR 402.02).
1. Given the current information that suggests green sea turtle movements within and through the action area are more likely to occur during the summer and fall when coastal water temperatures are warmest, the USACE should consider incorporating the anticipated seasonality of green sea turtle presence in the final project execution whenever feasible. Specifically, conducting in-water project activities during the winter/early spring should help lower the risk and/or extent of adverse effects. We also suggest incorporating monitoring and research information gathered 41 during the proposed project to help further inform how project activities could be scheduled and/or generally conducted to minimize the risk and/or extent of adverse effects.
2. The USACE should evaluate the feasibility of using a rigid sea turtle deflector draghead and/or similar turtle exclusion technology to further minimize the risk of hopper dredging entrainment during dredging activities on the U.S. West Coast. Such mitigation measures have been shown to effectively decrease incidental take for green sea turtles in other parts of the U.S.
The USACE should provide a summary of their evaluation and any recommendations to Dan Lawson at the email address listed above. If USACE and NMFS agree that utilizing turtle exclusion mitigation measures are feasible, then they should be implemented in future hopper dredging operations. If any injury or mortality is documented during the course of the proposed project, the USACE should consider implementing the most practicable exclusion technology available to avoid or minimize the risk of take exceedance.
3. During the proposed project and future nourishment events, the USACE should use the information gathered during the proposed project to facilitate outreach to the local community (e.g., fishing/boating communities) regarding the presence of green sea turtles and measures to help avoid harmful interactions with them. The USACE should also use outreach efforts to help enhance the available information during the proposed project by soliciting the City of San Clemente as the non-federal project sponsor to help collect information by reporting sightings of sea turtles to the USACE, NMFS, and/or available hotlines for live turtle observations (e.g., http://www.socalseaturtles.org/west-coast-sea-turtle-sightings.html#/).
4. Given the uncertainty associated with turtle abundance and use of the action area, the USACE should collaborate with NMFS to augment existing satellite tagging efforts of green sea turtles in southern California to improve our understanding of movement patterns in the action area and help understand the extent of impacts of the proposed project on green sea turtles and habitat utilization in the area. For example, the USACE should consider developing a funding transfer agreement to support NMFS’s involvement and expertise in the satellite tagging study of green sea turtles in the area.
11. Reinitiation of Consultation
This concludes formal consultation for the San Clemente Shoreline Protection Project.
Under 50 CFR 402.16(a): “Reinitiation of consultation is required and shall be requested by the Federal agency or by the Service where discretionary Federal agency involvement or control over the action has been retained or is authorized by law and: (1) If the amount or extent of taking specified in the incidental take statement is exceeded; (2) If new information reveals effects of the agency action that may affect listed species or critical habitat in a manner or to an extent not previously considered; (3) If the identified action is subsequently modified in a manner that causes an effect to the listed species or critical habitat that was not considered in the 42 biological opinion or written concurrence; or (4) If a new species is listed or critical habitat designated that may be affected by the identified action.”
3. DATA QUALITY ACT DOCUMENTATION AND PRE-DISSEMINATION REVIEW The Data Quality Act (DQA) specifies three components contributing to the quality of a document. They are utility, integrity, and objectivity. This section of the opinion addresses these DQA components, documents compliance with the DQA, and certifies that this opinion has undergone pre-dissemination review.
1. Utility
Utility principally refers to ensuring that the information contained in this consultation is helpful, serviceable, and beneficial to the intended users. The intended users of this opinion are the USACE. Individual copies of this opinion were provided to the USACE. The document will be available within 2 weeks at the NOAA Library Institutional Repository [https://repository.library.noaa.gov/welcome]. The format and naming adhere to conventional standards for style.
2. Integrity
This consultation was completed on a computer system managed by NMFS in accordance with relevant information technology security policies and standards set out in Appendix III, ‘Security of Automated Information Resources,’ Office of Management and Budget Circular A-130; the Computer Security Act; and the Government Information Security Reform Act.
3. Objectivity
Information Product Category: Natural Resource Plan
Standards: This consultation and supporting documents are clear, concise, complete, and unbiased; and were developed using commonly accepted scientific research methods. They adhere to published standards including the NMFS ESA Consultation Handbook, ESA regulations, 50 CFR 402.01 et seq., and the MSA implementing regulations regarding EFH, 50 CFR part 600.
Best Available Information: This consultation and supporting documents use the best available information, as referenced in the References section. The analyses in this opinion and EFH consultation contain more background on information sources and quality.
Referencing: All supporting materials, information, data and analyses are properly referenced, consistent with standard scientific referencing style.
43 Review Process: This consultation was drafted by NMFS staff with training in ESA and MSA implementation, and reviewed in accordance with West Coast Region ESA quality control and assurance processes.
4. REFERENCES
Amorocho, D.F., Reina, R., 2007. Feeding ecology of the East Pacific green sea turtleChelonia mydas agassiziiat Gorgona National Park, Colombia. Endanger. Species Res. 3, 43–51.
Avens, L. and M.L. Snover. 2013. Age and age estimation in sea turtles. In Wyneken, J., K.J.
Lohmann and K.J. Musick (Eds.). The Biology of Sea Turtles Volume III. CRC Press Boca Raton, FL, pp. 97-133.
Avery, H.W., J.R. Spotila, J.D. Congdon, R.U. Fischer, E.A. Standora, and S.B. Avery. 1993.
Roles of diet protein and temperature in the growth and nutritional energetics of juvenile Slider Turtles, Trachemys scripta.Physiological Zoology 66:902–925.
Barraza, A.D., L.M. Komoroske, C. Allen, T. Eguchi, R. Gossett, E. Holland, D.D. Lawson, R.A. LeRoux, A. Long, J.A. Seminoff, & C.G. Lowe. 2019. Trace metals in green sea turtles (Chelonia mydas) inhabiting two southern California coastal estuaries Chemosphere 223:342– 350.
Barraza, A., C. Allen, T. Eguchi, R. Gossett, E. Holland, L. Komoroske, D. Lawson, R. LeRoux, V. Lorenzi, J. Seminoff, & C. Lowe. 2020. Persistent organic pollutants in green sea turtles (Chelonia mydas) inhabiting two urbanized Southern California habitats. Marine Pollution Bulletin 153:110979.
Bedford, D.W. 1993. A Report of Biological Observations at Oceanside #1 and #2 Artificial Reefs, Carlsbad Artificial Reef, Pacific Beach Artificial Reef, and Mission Bay Park Artificial Reef. Prepared for the California Coastal Commission. California Department of Fish and Game Nearshore Sport Fish Habitat Enhancement Program.
Carrión-Cortez, J.A., Zárate, P., Seminoff, J.A., 2010. Feeding ecology of the green sea turtle (Chelonia mydas) in the Galapagos Islands. J. Mar. Biol. Assoc. United Kingdom 90, 1005– 1013.
Chacón, D., Arauz, R., 2001. Diagnostico regional y planificacion estrategica para la conservacion de las tortugas marinas en Centroamerica. Red Reg. para la Conserv. las tortugas Mar. Centroam. 134.
Chan, E.H. and H.C. Liew. 1995. Incubation temperatures and sex ratios in the Malaysian leatherback turtle Dermochelys coriacea. Biological Conservation 74:169-174. 44 Clifton, K., D. Cornejo, and R. Felger. 1982. Sea turtles of the Pacific coast of Mexico. Pp: 199- 209 In: K. Bjorndal (Ed.), Biology and Conservation of sea turtles. Smithsonian Inst. Press:
Washington, D.C.
Crear, D.P., D.D. Lawson, J.A. Seminoff, T. Eguchi, R.A. LeRoux, and C.G. Lowe. 2016.
Seasonal shifts in the movement and distribution of green sea turtles Chelonia mydas in response to anthropogenically altered water temperatures. Marine Ecology Progress Series 548:219-232.
Crear, Daniel P.; Lawson, Daniel D.; Seminoff, Jeffrey A.; Eguchi, Tomoharu; LeRoux, Robin A.; and Lowe, Christopher G. 2017. Habitat use and behavior of the east Pacific green turtle, Chelonia mydas in an urbanized system. Bulletin of the Southern California Academy of Sciences: Vol. 116: Iss. 1.
Delgado S.G., and W.J. Nichols. 2005. Saving sea turtles from the ground up: awakening sea turtle conservation in northwestern Mexico. Maritime Studies 4:89-104.
Duarte, C.M. 2002. The future of seagrass meadows. Environmental Conservation 29(2):192- 206.
Dutton, P. 2003. Molecular ecology of Chelonia mydas in the eastern Pacific Ocean. In:
Proceedings of the 22nd Annual Symposium on Sea Turtle Biology and Conservation, April 4-7, 2002, Miami, Florida.
Dutton, P.H., M.P. Jensen, A. Frey, E. LaCasella, G.H. Balazs, P. Zarate, O. Chassin-Noria, S.A.
Sarti-Martinez and E. Velez. 2014. Population structure and phylogeography reveal pathways of colonization by a migratory marine reptile (Chelonia mydas) in the central and eastern Pacific.
Ecology and Evolution. doi:10.1002/ece3.1269.
Dutton, P.H., R.A. LeRoux, EL. LaCasella, J.A. Seminoff, T. Eguchi and D.L. Dutton. 2019.
Genetic analysis and satellite tracking reveal origin of the green turtles in San Diego Bay. Marine Biology. 166:3. https://doi.org/10.1007/s00227-018-3446-4 Ecomarine Consulting LLC and Anghera Environmental. 2019. San Clemente Flood Risk Management Project U.S. Army Corps of Engineers Pre-Project Surfgrass Monitoring Report Year 1 Survey Results. Prepared for Chambers Group, Inc. and U.S. Army Corps of Engineers, Los Angeles District.
Ecomarine Consulting LLC and Anghera Environmental. 2020. San Clemente Flood RiskManagement Project U.S. Army Corps of Engineers Pre-Project Surfgrass Monitoring ReportYear 2 Survey Results. Prepared for Chambers Group, Inc. and U.S. Army Corps of Engineers, Los Angeles District.
45 Eguchi, T., J.A. Seminoff, R.A. LeRoux, P.H. Dutton, D.L. Dutton. 2010. Abundance and survival rates of green turtles in an urban environment: coexistence of humans and an endangered species. Marine Biology 157:1869-1877.
Eguchi, T., Seminoff, J.A., LeRoux, R.A., Prosperi, D., Dutton, D.L., and Dutton, P.H. 2012.
Morphology and growth rates of the green sea turtle (Chelonia mydas) in a northern-most temperate foraging ground. Herpetologica 68(1): 76-87.
Eguchi, T., Bredvik, J., Graham, S., LeRoux, R., Saunders, B., and J.A. Seminoff. 2020. Effects of a power plant closure on home ranges of green turtles in an urban foraging area. Endangered Species Research 41: 265-277.
Hanna, M.E., Bredvik J., Graham S.E., Saunders B., Seminoff J.A., Eguchi T., and C. Turner Tomaszewicz. 2020. Movements and habitat use of green sea turtles at the Seal Beach National Wildlife Refuge, CA. Prepared for Naval Weapons Station Seal Beach, California, September 2020.
Hanna M.E., Chandler E.M., Semmens B.X., Eguchi T, Lemons G.E., and Seminoff J.A. 2021 Citizen-Sourced Sightings and Underwater Photography Reveal Novel Insights About Green Sea Turtle Distribution and Ecology in Southern California. Front. Mar. Sci. 8:671061. doi:
10.3389/fmars.2021.671061
Harris, H. 2014. Sea turtle necropsy report on SWFSC-MT-2012-10 recovered November 4, 2012 from Moonlight Beach near Encinitas, CA. Necropsy report completed by NOAA contract veterinarian Heather Harris on November 3, 2014.
Hazel, J., Lawler, I., Marsh, H., and Robson, S. 2007. Vessel speed increases collision risk for the green turtle Chelonia mydas. Endangered Species Research. 3. 105-113. 10.3354/esr003105.
Hazel, J., Lawler, I.R. and M. Hamann. 2009. Diving at the shallow end: green turtle behavior in near-shore foraging habitat. J.Expt. Mar.Biol.Ecol., 371: 84-92.
Howo, K. 2022. Email communication providing rocky reef burial estimate.
Howo, K. 2023. Email communication clarifying estimate of hopper dredge roundtrips.
Johnson, M.R., Williams, S.L., Lieberman, C.H., and A. Solbak. 2003. Changes in the abundance of the seagrasses Zostera marina L. (eelgrass) and Ruppia maritima (L.) widgeongrass) in San Diego, California, Following an El Nino Event. Estuaries 26: 106-115.
Kaska, Y., C. Ilgaz, A. Ozdemir, E. Baskale, O. Ttirkozan, I. Baran, and M. Stachowitsch. 2006.
Sex ratio estimations of loggerhead sea turtle hatchlings by histological examination and nest temperatures at Fethiye beach, Turkey. Naturwissenschaften 93:338-343. 46 Lawson, D., C. Fahy, J. Seminoff, T. Eguchi, R LeRoux, P. Ryono, L. Adams, and M.
Henderson. 2011. A report on recent green sea turtle presence and activity in the San Gabriel River and vicinity of Long Beach, California. Poster presentation at the 31st Annual Symposium on Sea Turtle Biology and Conservation in San Diego, California.
Lemons, G., R. Lewison, L. Komoroske, A. Goas, C.T. Lai, P. Dutton, T. Eguchi, R. LeRoux, and J. Seminoff. 2011. Trophic ecology of green sea turtles in a highly urbanized bay: Insights from stable isotopes and mixing models. Journal of Experimental Marine Biology and Ecology 405:25-32.
LeRoux, R.A., E.L. LaCasella, T. Eguchi, C. Fahy, J. Schumacher, G. Lemons, J. Viezbicke, J.
Greenman, J. Cordaro, P.H. Dutton, J.A. Seminoff. Increasing trends in green turtle (Chelonia mydas) strandings in southern California, USA from 1980-2018: A cause for concern? Presentation at the 39th Annual Symposium on Sea Turtle Biology and Conservation in Charleston, South Carolina.
Lopez-Mendilaharsu, M., S.C. Gardner, J.A. Seminoff, and R. Riosmena-Rodriguez. 2004.
Identifying critical foraging habitats of the green turtle (Chelonia mydas) along the Pacific coast of the Baja California peninsula, Mexico.
MacDonald, B.D., S.V. Madrak, R.L. Lewison, J.A. Seminoff, and T. Eguchi. 2013. Fine scale diel movement of the east Pacific green turtle, Chelonia mydas, in a highly urbanized foraging environment. Journal of Experimental Marine Biology and Ecology 443: 56-64.
Madrak, S.V., Lewison, R.L., Eguchi, T., Klimley, A.P., and J.A. Seminoff. Effects of ambient temperature on dive behavior of East Pacific green turtles before and after a power plant closure.
Marine Ecology Progress Series 683: 157-168.
Mancini, A., Koch, V., Seminoff, J., and Madon, B. 2012. Small-scale gill-net fisheries cause massive green turtle Chelonia mydas mortality in Baja California Sur, Mexico. Oryx 46(1), 69-
77. doi:10.1017/S0030605310001833
Matsuzawa, Y., K. Sato, W. Sakamoto, and K.A. Bjorndal. 2002. Seasonal fluctuations in sand temperature: effects of the incubation period and mortality of loggerhead sea turtle (Caretta caratta) pre-emergent hatchlings in Minabe, Japan. Marine Biology 140:629-646.
Merkel & Associates, Inc. 2023. San Diego Regional Eelgrass Surveys. Prepared for San JoseState University Research Foundation and San Diego Water Quality Control Board.
National Marine Fisheries Service and U.S. Fish and Wildlife Service. 1998. Recovery Plan for U.S. Pacific Populations of the East Pacific Green Turtle (Chelonia mydas). National Marine Fisheries Service, Silver Spring, MD.
47 NMFS. 2016a. Interim Guidance on the Endangered Species Act Term "Harass". National Marine Fisheries Service Procedural Instruction 02-110-19. December 21, 2016. https://www.fisheries.noaa.gov/webdam/download/64690357 National Marine Fisheries Service. 2020. South Atlantic Regional Biological Opinion for Dredging and Material Placement Activities in the Southeast United States. Provided to U.S.
Army Corps of Engineers and Bureau of Ocean Energy Management.
NMFS and USFWS. 2007. Green Sea Turtle (Chelonia mydas). 5-Year Review: Summary and Evaluation. 105 p.
Nearshore and Wetland Surveys. 2018. Preliminary Summary of Nearshore Bottom Habitat and Submerged Aquatic Vegetation Assessment. Project memorandum re: Pre-construction Monitoring for Rocky Reef/Surfgrass Habitat in the San Clemente Pier Area. Dated April 11,2018.
Ramirez, A, Kot, CY, Piatkowski, D. 2017. Review of sea turtle entrainment risk by trailing suction hopper dredges in the US Atlantic and Gulf of Mexico and the development of the ASTER decision support tool. Sterling (VA): US Department of the Interior, Bureau of Ocean Energy Management. OCS Study BOEM 2017-084. 275 pp.
Renaud ML, Carpenter JA, Williams JA (1994) Activities of juvenile green turtles, Chelonia mydas, at a jettied pass in South Texas. Fish Bull 93: 586−593.
Schofield. G., C.M Bishop, G. MacLean, P. Brown, M. Baker, K.A. Katselidis, P. Dimopoulos, J.D Pantis, and G.C. Hays. 2007. Novel GPS tracking of sea turtles as a tool for conservation management. J.Expt. Mar.Biol.Ecol. 347:58-68.
Seminoff, J.A., Resendiz, A., Nichols, W.J., 2002. Home range of green turtles Chelonia mydas at a coastal foraging area in the Gulf of California, Mexico. Mar. Ecol. Prog. Ser. 242, 253– 265.
Seminoff, J.A., Resendiz, A., Nichols, W.J., 2002. Diet of East Pacific Green Turtles (Chelonia mydas) in the Central Gulf of California, México. J. Herpetol. 36, 447–453.
Seminoff, J.A., Resendiz, A., Nichols, W.J., Jones, T.T., 2002. Growth Rates of Wild Green Turtles (Chelonia mydas) at a Temperate Foraging Area in the Gulf of California, México.
Copeia 610–617.
Seminoff, J.A., C.D. Allen, G.H. Balazs, P.H. Dutton, T. Eguchi, H.L. Haas, S.A. Hargrove,M.P.
Jensen, D.L. Klemm, A.M. Lauritsen, S.L. MacPherson, P. Opay, E.E. Possardt, S.L. Pultz, E.E.
Seney, K.S. Van Houtan, R.S. Waples. 2015. Status Review of the Green Turtle (Chelonia 48 mydas) Under the U.S. Endangered Species Act. NOAA Technical Memorandum, NOAANMFS-SWFSC-539. 571pp.
Seminoff J.A. and Glass M. 2020. Red List Assessment. Green turtle, Chelonia mydas, Eastern Pacific Region. IUCN Marine Turtle Specialist Group. 24 pp.
Seminoff, J. A., Komoroske, L. M., Amorocho, D., Arauz, R., Chacón-Chaverrí, D., de Paz, N., Dutton, P. H., Donoso, M., Heidemeyer, M., Hoeffer, G., Todd Jones, T., Kelez, S., Lemons, G.
E., Rguez-Baron, J. M., Sampson, L., Santos Baca, L., Steiner, T., Vejar Rubio, M., Zárate, P., Zavala-Norzagaray, A., and Popp, B. N.. 2021. Large-scale patterns of green turtle trophic ecology in the eastern Pacific Ocean. Ecosphere 12( 6):e03479. 10.1002/ecs2.3479 Senko, J, A.J. Schneller, J. Solis, F. Ollervides, W.J. Nichols. 2011. People helping turtles, turtles helping people: Understanding resident attitudes towards sea turtle conservation and opportunities for enhanced community participation in Bahia Magdalena, Mexico. Ocean and Coastal Management 54:148-157.
Short, F.T., and H.A. Neckles. 1999. The effects of climate change on seagrasses. Aquatic Botany 63:169-196.
University of California Santa Barbara. 2023. Annual Public Workshop San Onofre Generating Station (SONGS) Artificial Reef Mitigation Project, Wednesday, April 5, 2023. http://marinemitigation.msi.ucsb.edu/
Van Houtan K.S., and O.L. Bass. 2007. Stormy Oceans are associated with declines in sea turtle hatching. Current Biology Vol 17 No.15.
Wallace B.P., A.D. DiMatteo, B.J. Hurley, E.M. Finkbeiner, and A.B. Bolten. 2010. Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales. PLoS ONE 5(12): e15465.doi:10.13711joumal.pone.0015465.
Webster, P J., G.J. Holland, J.A. Curry, and H.-R. Chang. 2005. Changes in tropical cyclone number, duration, and intensity in a warming environment. Science 309:1844-1846.