Conservation implications of sea turtle nesting trends: elusive recovery of a globally important loggerhead population

Ceriani, Simona A.; Casale, Paolo; Brost, M.; Leone, Erin H.; Witherington, Blair E.

doi:10.1002/ecs2.2936

Cited by 77 publications

(74 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recovery of NRU loggerheads appears to be associated with an increasing contribution of females foraging in the MAB, therefore managing anthropogenic threats to turtle survival and habitat quality in the MAB, as well as migratory corridors and overwintering sites in the SAB, remain conservation priorities for this subpopulation [3,[64][65]. Similarly, the recent rebound in PFRU nesting following a period of decline in the early 2000's [66][67] is likely linked to conditions in the SNWA and EGoM foraging areas. Managing threats and productivity in these foraging areas will continue to support the health and stability of the PFRU, a globally important subpopulation of loggerheads [3,[64][65].…”

Section: Conservation Implicationsmentioning

confidence: 99%

Identifying patterns in foraging-area origins in breeding aggregations of migratory species: Loggerhead turtles in the Northwest Atlantic

et al. 2020

View full text Add to dashboard Cite

Population assessments conducted at reproductive sites of migratory species necessitate understanding the foraging-area origins of breeding individuals. Without this information, efforts to contextualize changes in breeding populations and develop effective management strategies are compromised. We used stable isotope analysis of tissue samples collected from loggerhead sea turtles (Caretta caretta) nesting at seven sites in the Northern Recovery Unit (NRU) of the eastern United States (North Carolina, South Carolina and Georgia) to assign females to three separate foraging areas in the Northwest Atlantic Ocean (NWA). We found that the majority of the females at NRU nesting sites (84.4%) use more northern foraging areas in the Mid-Atlantic Bight, while fewer females use more proximate foraging areas in the South Atlantic Bight (13.4%) and more southerly foraging areas in the Subtropical Northwest Atlantic (2.2%). We did not find significant latitudinal or temporal trends in the proportions of NRU females originating from different foraging areas. Combining these findings with previous data from stable isotope and satellite tracking studies across NWA nesting sites showed that variation in the proportion of adult loggerheads originating from different foraging areas is primarily related differences between recovery units: individuals in the NRU primarily use the Mid-Atlantic Bight foraging area, while individuals from the three Florida recovery units primarily use the Subtropical Northwest Atlantic and Eastern Gulf of Mexico foraging areas. Because each foraging area is associated with its own distinct ecological characteristics, environmental fluctuations and anthropogenic threats that

show abstract

Section: Conservation Implicationsmentioning

confidence: 99%

Identifying patterns in foraging-area origins in breeding aggregations of migratory species: Loggerhead turtles in the Northwest Atlantic

et al. 2020

View full text Add to dashboard Cite

show abstract

“…R. Soc. B 287: 20200220 this period [33]. Thus, for all three species of turtles bycatch rates appear to follow broad-scale population-level trends and regulations aimed at reducing turtle bycatch do not appear to have kept pace with Kemp's ridley or green turtle population growth.…”

Section: Discussionmentioning

confidence: 96%

Managing fisheries in a world with more sea turtles

Putman¹,

Hawkins

Gallaway³

2020

Proc. R. Soc. B.

View full text Add to dashboard Cite

For decades, fisheries have been managed to limit the accidental capture of vulnerable species and many of these populations are now rebounding. While encouraging from a conservation perspective, as populations of protected species increase so will bycatch, triggering management actions that limit fishing. Here, we show that despite extensive regulations to limit sea turtle bycatch in a coastal gillnet fishery on the eastern United States, the catch per trip of Kemp's ridley has increased by more than 300% and green turtles by more than 650% (2001–2016). These bycatch rates closely track regional indices of turtle abundance, which are a function of increased reproductive output at distant nesting sites and the oceanic dispersal of juveniles to near shore habitats. The regulations imposed to help protect turtles have decreased fishing effort and harvest by more than 50%. Given uncertainty in the population status of sea turtles, however, simply removing protections is unwarranted. Stock-assessment models for sea turtles must be developed to determine what level of mortality can be sustained while balancing continued turtle population growth and fishing opportunity. Implementation of management targets should involve federal and state managers partnering with specific fisheries to develop bycatch reduction plans that are proportional to their impact on turtles.

show abstract

“…Furthermore, due to the time lag between hatchling production and recruitment to the adult female stage, nest numbers do not indicate absolute abundance for all life-stages or overall trends for entire populations (Mortimer, 1995). However, nest counts are the most common index of sea turtle population monitoring as they can be systematically obtained and compared among locations (Ceriani et al, 2019) and monitoring and protection of nesting assemblages is crucial for successful conservation (McClenachan et al, 2006). Nevertheless, sea turtle nesting abundance time series rarely include long-term data (from more than 20 years of monitoring), which are necessary to detect significant changes in abundance (Mazaris et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Cayman Islands Sea Turtle Nesting Population Increases Over 22 Years of Monitoring

et al. 2021

View full text Add to dashboard Cite

Given differing trajectories of sea turtle populations worldwide, there is a need to assess and report long-term population trends and determine which conservation strategies are effective. In this study, we report on sea turtle nest monitoring in the Cayman Islands over a 22-year period. We found that green (Chelonia mydas) and loggerhead (Caretta caretta) nest numbers increased significantly across the three islands since monitoring began in 1998, but that hawksbill nest numbers remained low with a maximum of 13 nests recorded in a season. Comparing the first 5 years of nest numbers to the most recent 5 years, the greatest percentage increase in green turtle nests was in Grand Cayman from 82 to 1,005 nests (1,126%), whereas the greatest percentage increase for loggerhead turtle nests was in Little Cayman from 10 to 290 nests (3,800%). A captive breeding operation contributed to the increase in the Grand Cayman green turtle population, however, loggerhead turtles were never captive-bred, and these populations began to increase after a legal traditional turtle fishery became inactive in 2008. Although both species have shown significant signs of recovery, populations remain at a fragment of their historical level and are vulnerable to threats. Illegal harvesting occurs to this day, with multiple females taken from nesting beaches each year. For nests and hatchlings, threats include artificial lighting on nesting beaches, causing hatchlings to misorient away from the sea, and inundation of nests by seawater reducing hatch success. The impacts of lighting were found to increase over the monitoring period. Spatial data on nest distribution was used to identify critical nesting habitat for green and loggerhead turtles and is used by the Cayman Islands Department of Environment to facilitate remediation of threats related to beachside development and for targeted future management efforts.

show abstract

Conservation implications of sea turtle nesting trends: elusive recovery of a globally important loggerhead population

Abstract: Understanding population status and trends is important for developing and evaluating man-

Cited by 77 publications

References 49 publications

Identifying patterns in foraging-area origins in breeding aggregations of migratory species: Loggerhead turtles in the Northwest Atlantic

Identifying patterns in foraging-area origins in breeding aggregations of migratory species: Loggerhead turtles in the Northwest Atlantic

Managing fisheries in a world with more sea turtles

Cayman Islands Sea Turtle Nesting Population Increases Over 22 Years of Monitoring

Contact Info

Product

Resources

About