Biology subjects

Seminoff, J. A.

Publications and source records attributed to Seminoff, J. A..

6 recordsLinked to original sources

bioRxiv2026

Area use and residency behaviour at reproductive and foraging areas of green turtles from the largest rookery in the Atlantic

The conservation of migratory marine megavertebrates depends on the protection of different areas during their life cycles. Many populations have recovered following exploitation-driven declines. Green turtles exemplify successful efforts protecting reproductive populations, reducing harvesting, promoting population recoveries globally. Tortuguero, Costa Rica, the second largest rookeries for green turtles worldwide, implemented long-term conservation efforts leading to a population recovery, which is now in decline. This study investigates migratory connectivity of green turtles from Tortuguero across the Caribbean, and the role marine protected areas (MPAs) play in protecting key habitats supporting this population. Over 25 years, we satellite tagged 63 female green turtles to study their internesting and post-nesting foraging movements. Applying a state-space model, we calculated a movement-persistence index, to separate internesting and foraging periods. We calculated turtles' utilization distribution areas for both periods. To assess the protection coverage at each end of the migration, we calculated time spent within and outside MPAs. Tracked turtles spent a median of 42.3 days (SD=18.8, range=12-80) within 30 km offshore before departing the internesting area, spending just 23.0% of time within nearby MPAs. After nesting, turtles migrated to 14 different foraging areas, Miskitos Cays, Nicaragua hosted the most turtles (n=23). Mean transmission time in foraging areas was 175.6 days (SD=126.0; range=13-544). Generally, turtles foraged 58.0% of the time within MPAs boundaries; however, ~32% of tracked turtles foraged outside MPAs. Considering all known stressors, we found this population to be insufficiently protected at either end of their migratory cycle, remaining vulnerable to regional threats.

ecology↗

bioRxiv2026

A GENOMIC BASIS FOR TRANS-OCEANIC SEA TURTLE MIGRATION

Long-distance migration has evolved repeatedly across the animal kingdom, yet the underlying processes giving rise to and maintaining these complex eco-behavioral phenotypes remain poorly understood. Here, we present the first evidence of genomic determinants of migratory phenotypes in sea turtles, using whole genome resequencing to demonstrate that complex genomic architecture underlies divergent migratory destinations and reproductive timing in the critically endangered western Pacific leatherback turtle (Dermochelys coriacea). Individuals from this admixed population that navigate to foraging grounds on opposite sides of the Pacific Ocean have a putative inversion on chromosome 2 encompassing one gene, potentially conferring pleiotropic physiological effects and supporting magnetoreception. Genomic architecture underlying divergent reproductive timing is more dispersed, aligned with reduced gene flow, and is associated with genes that may influence reproductive success. Genes underlying both traits suggest a role for neurodevelopment and memory. Our study adds to the increasing evidence of at least partial genomic control of migratory traits in wild populations, with important potential implications for conservation measures such as translocation and genetic rescue. Our results align with a growing body of work describing complex genomic architecture and structural variants underlying key eco-behavioral traits, advancing the understanding of evolution of long-distance migration across taxa.

ecology↗

bioRxiv2025

Ecological insights and management implications of the global migratory connectivity of green turtles

AimGreen turtles are a widely distributed and highly migratory species, despite extensive data on the movement of green turtles, there is no global synthesis on the subject, limiting a holistic understanding of their movement. Based on three decades of published literature, we present the first global model of migratory connectivity for green turtles. LocationGlobal. Time Period1990-2022. Major Taxa StudiedGreen Sea Turtle (Chelonia mydas) MethodsWe conducted a structured literature review extracting georeferenced information on the movement of green turtles from 1990 to 2022, aggregating this information into a single connectivity model, defining sites and "metasites" as nodes of connectivity. We then evaluate the connectivity routes from nesting areas to foraging sites for each RMU, identifying those trajectories moving outside and across the boundaries of these areas. ResultsWe found an increasing number of studies assessing movement of green turtles, with a total of 113 sources of migratory connectivity information. We identified 474 sites, representing locations where green turtles were observed (124 of these being nesting sites). Migratory connections from nesting sites ranged from resident turtles never leaving the area, to rookeries linked to 13 different sites, some over 5,000 km apart. This long-distance connectivity exposes populations to threats across disparate locations. Most connections traversed national jurisdictions, including crossing different Regional Management Units Main ConclusionsWe compiled the largest available dataset describing movement of green turtles worldwide and present the first global model of their migratory connectivity. This model provides ecological insights into regional differences in life histories, identifies geographic and demographic gaps in sampling, and provides baseline information on connectivity to support transboundary management of green turtle populations. The study highlights the need for larger collaborative efforts to aggregate knowledge beyond local jurisdictions, to inform and align effective management measures to protect this threatened species.

ecology↗

bioRxiv2023

Local Ecological Knowledge enhances our capacity to document potential climate sentinels: a loggerhead sea turtle (Caretta caretta) case study

Climate change is inducing rapid transformations in marine ecosystems, with a pronounced effect on top predators like loggerhead sea turtles (Caretta caretta). Loggerheads responsiveness to temperature fluctuations underscores their significance as a climate sentinel species. We present the first record of a loggerhead sea turtle in Monterey Bay, California, USA, documented through Local Ecological Knowledge (LEK) and community or citizen science (CS), highlighting the pivotal role of these approaches in documenting species occurrences beyond anticipated habitats during climatic anomalies. In rapidly changing conditions, rigorously documented CS and LEK offer a crucial complement to conventional scientific methods, providing high-quality data with extensive coverage-- especially for elusive species--and yielding insights into emerging phenomena.

ecology↗

bioRxiv2021

Integrating ecological monitoring and local ecological knowledge to evaluate conservation outcomes

Successful conservation of long-lived species requires reliable understanding of long-term trends and historical baselines. Using a green turtle (Chelonia mydas) foraging aggregation in the northern Gulf of California, Mexico as case study, we integrated scientific monitoring data with historic catch rate reconstructions derived from Local Ecological Knowledge (LEK). Models fit to LEK and monitoring data indicate that turtle abundance is increasing, but only after ~40 years of safeguarding the species nesting and foraging habitats in Mexico. However, as population declines occurred 75% faster than increases, and current abundance is at ~60% of historical baseline levels, indicating the need for sustained, long-term conservation actions. This study demonstrates the potential of linking LEK and ecological science to provide critical information for conservation, by establishing reference baselines and gauging population status, while promoting equitable and sustainable futures for local communities.

ecology↗

bioRxiv2017

Hematology, biochemistry, and toxicology of wild hawksbill turtles (Eretmochelys imbricata) nesting in mangrove estuaries in the eastern Pacific Ocean

Sea turtles are a keystone species and are highly sensitive to changes in their environment, making them excellent environmental indicators. In light of environmental and climate changes, species are increasingly threatened by pollution, changes in ocean health, habitat alteration, and plastic ingestion. There may be additional health related threats and understanding these threats is key in directing future management and conservation efforts, particularly for severely reduced sea turtle populations. Hawksbill turtles (Eretmochelys imbricata) are critically endangered, with those in the eastern Pacific Ocean (Mexico-Peru) considered one of the most threatened sea turtle populations in the world. This study establishes baseline health parameters in hematology and blood biochemistry as well as tested for heavy metals and persitent organic pollutants in eastern Pacific hawksbills at a primary nesting colony located in a mangrove estuary. Whereas hematology and biochemistry results are consistent with healthy populations of other species of sea turtles, we identified differences in packed cell volume, heterophils and lympohcyte counts, and glucose when comparing our data to other adult hawksbill analysis (1), (2), (3). Our analysis of heavy metal contamination revealed a mean blood level of 0.245 ppm of arsenic, 0.045 ppm of lead, and 0.008 ppm of mercury. Blood levels of persistent organic pollutants were below the laboratory detection limit for all turtles. Our results suggest that differences in the feeding ecology of eastern Pacific hawksbills in mangrove estuaries may make them less likely to accumulate persistent organic pollutants and heavy metals in their blood. These baseline data on blood values in hawksbills nesting within a mangrove estuary in the eastern Pacific offer important guidance for health assessments of the species in the wild and in clinical rehabilitation facilities, and underscore the importance of preventing contamination from point and non-point sources in mangrove estuaries, which represent primary habitat to hawksbills and myriad other marine species in the eastern Pacific Ocean.

zoology↗