Green Sea Turtle Chelonia Mydas Research Articles

A dataset of sea turtle occurrences around the Taiwan coast.

We describe a dataset of sea turtle sightings around the coast of Taiwan and its islands (Hoh and Fong 2022). This data collection was initiated by TurtleSpot Taiwan, a citizen-science project that collects sea turtle sighting data. This dataset includes 3,515 sighting data dated from March 2010, except most of the data (n = 3,128; 89%) were collected between June 2017 to December 2021. Sightings were reported by citizen scientists to the Facebook Group of TurtleSpot Taiwan by providing occurrence information. We also requested photos and videos for species identification and to record any physical abnormality of the turtle, if observable. In addition to recording data often associated with an occurrence, TurtleSpot aims to identify each sea turtle up to the individual level using the Photo Identification (Photo ID) method. Hence, if photos of left facial scutes were available, the sighted individual can be identified and given a unique turtle ID. In total, 762 individuals were assigned a turtle ID, comprising 723 Greens (Cheloniamydas), 38 Hawksbills (Eretmochelysimbricata) and one Olive Ridley (Lepidochelysolivacea) turtle. This dataset is now publicly opened in Global Biodiversity Information Facility (GBIF) and available for download. It is hoped that the data may assist in future ecological studies and the development of conservation measures. This dataset contains 3,515 occurrence records of sea turtles (Cheloniidae) and is currently the largest public dataset of sea turtle sighting records in Taiwan. Post-publication of this dataset to the GBIF platform demonstrated that the number of Green sea turtle Cheloniamydas records in Taiwan is one of the largest in the world (last accessed date: 15-10-2022). The data served as the foundation for understanding biogeography and sea turtle ecology in Taiwan's coastal waters.

Bacterial and fungal pathogens in granulomatous lesions of Chelonia mydas in a significant foraging ground off southern Brazil.

The green sea turtle Chelonia mydas inhabit near-shore areas exposed to threatening anthropogenic activities. The granulomatous lesions in these animals may indicate infectious diseases that can be associated with environmental contamination and hazards to human health. This study aimed to characterize the granulomatous inflammation associated with bacterial and fungal infection in C. mydas off Paraná state. From September 2015 to February 2019, systematic monitoring was performed by the Santos Basin Beach Monitoring Project for sea turtles'carcasses recovery, necropsy, and cause of death diagnosis. The tissue samples were fixed in buffered formalin 10% for histochemical analysis and frozen for molecular analysis to fungi detection (Internal Transcribed Spacer region of the nuclear rDNA) and bacteria detection (16S ribosomal gene). From a total of 270 C. mydas, granulomatous lesions were observed in different organs of 63 (23.3%) individuals. The histological analysis indicated lesions in 94 organs, affecting most respiratory and digestive systems. Bacteria were identified in 25 animals, including an acid-fast bacteria detected in one animal, and fungi in 24 C. mydas. The fungi species included the genus Candida (Candida zeylanoides, n = 3), Yarrowia (Yarrowia lipolytica, n = 9; Yarrowia deformans, n=5; and Yarrowia divulgata, n = 1), and Cladosporium anthropophilum (n = 1). No species of bacteria was identified by molecular testing. All fungi species identified are saprobic, some are important to food and medical industries, but are also pathogens of humans and other animals. Therefore, long-term monitoring of these pathogens and the C. mydas health may indicate changes in environmental quality, possible zoonotic diseases, and their effects.

Effects of moisture during incubation on green sea turtle (Chelonia mydas) development, morphology and performance

While the effect of temperature on embryonic development in sea turtles has been well studied over recent years, our understanding of the effect of substrate moisture, another important environmental variable, is limited. High sand moisture decreases nest temperature through evaporative and direct cooling during rainfall, but its direct effect on hatchling development, morphology and performance is unclear. To address this knowledge gap, we incubated 40 green sea turtle Chelonia mydas clutches in a beach hatchery under either high (~8% v/v) or low (~5% v/v) sand moisture concentrations for the duration of embryonic development. In half of the clutches, temperature sensors were deployed to measure any effect of sand moisture on nest temperature. As hatchlings emerged, we measured body size and locomotory performance during the first 24 h, an important period of frenzied activity for sea turtles. We excavated clutches post-emergence to determine hatching success, emergence success and to determine the stage of embryonic death for unsuccessful eggs. High moisture concentrations increased incubation duration, decreased nest temperature and had marginal effects on hatchling morphology, but no effect on hatching success, stage of embryonic death, crawling speed or initial swimming performance. However, after 24 h of swimming, hatchlings from high-moisture clutches produced less mean swim thrust and spent less time powerstroking than hatchlings from low-moisture clutches, suggesting reduced swimming endurance and potentially impacting the ability of hatchlings to successfully disperse. The effect of moisture on nest temperature and hatchling endurance highlights the importance of considering rainfall patterns when predicting future impacts of climate change on sea turtle populations.

Fish assemblage structure response to seagrass bed degradation due to overgrazing by the green sea turtle Chelonia mydas at Iriomote Island, southern Japan

The fish assemblage structure response to rapid degradation of Enhalus acoroides seagrass beds due to overgrazing by green sea turtles (Chelonia mydas) was investigated at Iriomote Island, southern Japan, by visual censusing of fish species in several microhabitats in and around the beds (i.e., dense seagrass bed, grazed bed, their boundaries, and adjacent sandy area). Fish assemblage structure differed among the seagrass microhabitats, both species and individual numbers being higher in microhabitats with seagrass compared to overgrazed beds and unvegetated sandy areas, together with different species composition. In the dense seagrass beds and boundary areas (the border area between dense seagrass beds and grazed areas), seagrass-associated fishes such as the rabbit fish Siganus fuscescens and cardinal fish Ostorhinchus ishigakiensis were abundant and comparable with those in other seagrass beds in the area. In addition, the fish assemblages in those microhabitats varied seasonally, fish abundance being greater in summer due to higher levels of recruitment. In the grazed bed, benthic gobies, such as Ctenogobiops crocineus and Cryptocentrus caeruleomaculatus, were dominant (similarly so in unvegetated sandy areas), and seasonal variations in such assemblages were relatively low compared to those in dense seagrass microhabitats. The decrease in the abundance and diversity of seagrass-associated fish in the grazed areas could be explained partly by the shortage of vegetation (< 20 cm in leaf length) for shelter and feeding throughout the year. The results suggested that the degradation of seagrass beds due to overgrazing by green turtles has a deleterious effect on fish assemblages, and that future conservation and management strategies for seagrass beds should consider both their associated fish communities and green turtles.

Molecular Crux of Hair Cell Mechanotransduction Machinery

Although 62 years have elapsed since the first report of hereditary deafness in a mouse strain, the molecular mechanism of hair cell mechanotransduction remains elusive. Three recent studies present crucial insights into the molecular crux of hair cell mechanotransduction machinery.

Genetic Diversity and Demographic Connectivity of Atlantic Green Sea Turtles at Foraging Grounds in Northeastern Colombia, Caribbean Sea

The Atlantic green sea turtle Chelonia mydas is a migratory and endangered species with a network of nesting rookeries and foraging grounds in the Atlantic basin that needs elucidation. Foraging grounds are important areas for immature turtle’s feeding and growth after pelagic migrations. Aggregations of sea turtles at these grounds usually come from genetically distinct nesting rookeries; therefore, they are called mixed stocks. The northeastern coast of Colombia has extensive seagrass and macroalgae marine ecosystems that constitute foraging grounds, and perhaps long-term developmental habitats for a significant number of immature C. mydas. However, it is unknown which C. mydas nesting rookeries may be using these ecosystems for feeding and development. This study estimated the genetic diversity and genetic origin of C. mydas mixed stocks at two foraging grounds in northeastern Colombia (Santa Marta and La Guajira), and inferred their connections to nesting rookeries groups in the Atlantic basin using mitochondrial Control Region (mtCR) as a marker. A high genetic diversity, evidenced by the high nucleotide and haplotype diversities, was found in both studied mixed stocks and may be explained by different contributing nesting rookeries groups found with mixed stock analyses. At least three genetically distinct groups from different sides of the Atlantic Basin contributed juveniles to the mixed stocks in Colombia. Observed demographic connectivity can be explained by the confluence of two major, opposite directions ocean currents by the study area, the Caribbean Current (westward) and the Panama-Colombia Countercurrent (eastward). The high diversity of turtles at Colombia’s foraging grounds suggests the area is an important link in the network of habitats used by C. mydas to be considered in management and transnational conservation planning for the species recovery.

Finding Crush: Environmental DNA Analysis as a Tool for Tracking the Green Sea Turtle Chelonia mydas in a Marine Estuary

Environmental DNA (eDNA) analysis is a rapid, non-invasive method for species detection and distribution assessment using DNA released into the surrounding environment by an organism. eDNA analysis is recognised as a powerful tool for detecting endangered or rare species in a range of ecosystems. Although the number of studies using eDNA analysis in marine systems is continually increasing, there appears to be no published studies investigating the use of eDNA analysis to detect sea turtles in natural conditions. We tested the efficacy of two primer pairs known to amplify DNA fragments of differing lengths (488 and 253 bp) from Chelonia mydas tissues for detecting C. mydas eDNA in water samples. The capture, extraction, and amplification of C. mydas eDNA from aquaria (Sea World, San Diego, CA, United States) and natural water (San Diego Bay, CA, United States) were successful using either primer set. The primer pair providing the shorter amplicon, LCMint2/H950g, demonstrated the ability to distinguish cross-reactive species by melt curve analysis and provided superior amplification metrics compared to the other primer set (LTCM2/HDCM2); although primer dimer was observed, warranting future design refinement. Results indicated that water samples taken from deeper depths might improve detection frequency, consistent with C. mydas behaviour. Overall, this pilot study suggests that with refinement of sampling methodology and further assay optimisation, eDNA analysis represents a promising tool to monitor C. mydas. Potential applications include rapid assessment across broad geographical areas to pinpoint promising locations for further evaluation with traditional methods.

First detection of the non-indigenous gastropod Rapana venosa in the southernmost coast of Brazil

The rapa whelk Rapana venosa is a predator of bivalves, native to Eastern Asia. It was first recorded outside its native distribution in 1946 in the Black Sea and since then has invaded estuarine and marine waters worldwide. The present findings increase the known geographic distribution of reproducing populations to eight regions: Black, Adriatic and Aegean seas, the coast of Brittany, the coast of the Netherlands, Chesapeake Bay, La Plata River estuary in Argentina-Uruguay and the southern Brazilian coast. We present the first records of R. venosa in the southernmost Brazilian coast (between Hermenegildo and Cassino Beaches, RS), based on 110 specimens, one as an epibiont associated with the green sea turtle Chelonia mydas. The majority of the specimens were found along Cassino beach, close to the inlet of the Patos Lagoon estuary (~32°S). Despite the highly variable salinity in the estuarine area, R. venosa was able to invade this area, probably due to its high fecundity and fertility, fast growth rate and high tolerance to salinity and temperature variations, all characteristics of a successful invader. The presence of this species further to the north (about 800 km) of the La Plata River estuary shows that it is dispersing along the southwestern Atlantic. Its interaction with green turtles may be of global importance for sea turtle conservation, given the observed potential for dispersal using turtle carapaces, which may affect their swimming and feeding. Our study contributes to the knowledge of bioinvasion in the Southwestern Atlantic coast.

New records of Planes crabs associated with sea turtles in Africa and adjacent waters

Crabs of the genus Planes (family Grapsidae) live on floating debris and pelagic animals and spend their lives rafting at the surface of the open ocean. Among living substrata, Planes minutus is frequently found associated with sea turtles. However, prior to this study, crabs had never been documented on sea turtles in continental Africa or in the western Indian Ocean. We found P. minutus associated with olive ridley sea turtle Lepidochelys olivacea nesting and foraging/pre-nesting in Gabon, and with loggerhead Caretta caretta and green sea turtle Chelonia mydas foraging off the east coast of South Africa, as well as loggerheads nesting in Cape Verde and loggerheads foraging off Réunion. No crabs were found on nesting loggerheads surveyed in Oman. We integrate these new findings with a review of all known records of Planes–sea turtle interactions in the Atlantic and Indian oceans and the Mediterranean Sea, to better understand the geographic distribution and ecological characteristics of such associations.

Decadal Monitoring in Bermuda Shows a Widespread Loss of Seagrasses Attributable to Overgrazing by the Green Sea Turtle Chelonia mydas

The condition of seagrass habitat and the marine environment on the Bermuda Platform, a mid-oceanic shallow water habitat in the northwest Atlantic, has been monitored since 2006. The overall oceanic climate of the Platform is subtropical; the Platform supports communities of tropical marine seagrasses, including Thalassia testudinum, Syringodium filiforme, Halodule sp., and Halophila decipiens. At the beginning of the study, the general condition of seagrass beds at 17 permanent offshore and nearshore sites indicated that 14 were healthy, complex, and thriving communities, and three represented offshore beds, which had declined precipitously prior to the initiation of study. Over the period of the study, seagrass beds declined at all 17 sites; three beds disappeared, and there was no recovery at the sites known to have declined prior to 2006. Over the same period, there was no apparent negative change in the water quality overlying the seagrass beds. Assessments of elemental content, stable isotopic composition, and leaf morphology indicated that grazing by the green turtle (Chelonia mydas) is driving the decline of the seagrasses of Bermuda. Given the feeding behavior of these turtles on the Bermuda Platform, human intervention may be required to mitigate the decline of seagrass in Bermuda.

Impact of exceptional growth rates on estimations of life-stage duration in Hawaiian green sea turtles

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 35:181-193 (2018) - DOI: https://doi.org/10.3354/esr00885 Impact of exceptional growth rates on estimations of life-stage duration in Hawaiian green sea turtles Shawn K. K. Murakawa1,*, Melissa L. Snover2 1NOAA Fisheries, Pacific Islands Fisheries Science Center, 1845 Wasp Boulevard, Building 176, Honolulu, Hawaii 96818, USA 2Population Ecology Services, PO Box 3673, Pago Pago, American Samoa 96799, USA *Corresponding author: shawn.murakawa@noaa.gov ABSTRACT: The Hawaiian green sea turtle Chelonia mydas population has steadily increased since its protection under the US Endangered Species Act of 1978. However, an understanding of their recovery status is stymied by lack of certainty regarding the population age structure. Based on the observed slow growth rates of juveniles, current assessments place age at first reproduction in Hawaiian green sea turtles at 35-40 yr, although a recent study suggests 23 yr for this population. It is possible that somatic growth dynamics such as growth spurts have been missed by traditional mark-recapture studies. Skeletochronology provides annual longitudinal data on growth rates of marine turtles, allowing for the detection of rare but potentially important growth spurts. The present study uses skeletochronology to estimate growth rates and detect the frequency of growth spurts in 30-90 cm straight carapace length (SCL) Hawaiian green sea turtles. We found that growth spurts occurred throughout the life span, but peaked for males from 50 to 59.9 cm SCL and for females from 70 to 79.9 cm SCL. The growth rates were binned into 10 cm SCL size class bins, and 4 methods were used to estimate the mean growth rate for each bin. We found that mean growth rates overestimated life-stage durations for each of the methods, although the expectation of the lognormal distribution gave the least biased results. Our study suggests that infrequent growth spurts are not represented in mean growth rate statistics but that these spurts likely result in faster lifetime growth rates and lower age at first reproduction than has been estimated using traditional methods. KEY WORDS: Chelonia mydas · Age at first reproduction · Growth spurts · Humeri · Skeletochronology Full text in pdf format PreviousCite this article as: Murakawa SKK, Snover ML (2018) Impact of exceptional growth rates on estimations of life-stage duration in Hawaiian green sea turtles. Endang Species Res 35:181-193. https://doi.org/10.3354/esr00885 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 35. Online publication date: April 27, 2018 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2018 Inter-Research.

Long-term trends in abundance of green sea turtles (Chelonia mydas) assessed by non-lethal capture rates in a coastal fishery

Sea turtle populations underwent severe decline in historical times, mainly through harvesting eggs and adults on nesting beaches. With the reduction of this threat in many areas, coupled with other conservation actions, some populations have demonstrated encouraging recovery, although remaining below their previous levels and undergone additional modern threats such as incidental capture in fisheries and pollution. Trends in sea turtle populations have usually been assessed through monitoring of females or nests on nesting beaches. Here we present data from a 22-year monitoring period for a juvenile green sea turtle Chelonia mydas mixed-stock in southeastern Brazil that were incidentally captured in passive non-lethal pound nets. A total of 3639 green turtles were captured in 5323 fishing days.pound−1 with mortality rate of 2%. Captures occurred in all months, but bycatch rates, excluding recapture events, were higher in September and October, probably due to the recruitment of turtles migrating from southern areas, as well as recruits from the oceanic zone. Capture rates increased by 9.2% per year in the period from 1995 to 2016, in line with increasing source populations, particularly the main source contributor at Ascension Island, but also Trindade Island (Brazil) and Aves Island (Venezuela). Mean Curved Carapace Length of green turtles was higher during austral summer/early autumn and decreased markedly in May, probably due to the small-sized individuals that recruited to the study site. We show that the incidental capture of sea turtles in non-lethal fisheries, such as Brazilian pound nets, could also provide data on trends of populations nesting in distant places, and can contribute to the assessment of population status of sea turtles within Regional Management Units throughout the Atlantic Ocean.

Fine scale diel movement of the east Pacific green turtle, Chelonia mydas, in a highly urbanized foraging environment

Protection of endangered species requires an understanding of their spatial ecology in relation to human activities. Recent improvements in monitoring technologies, such as automated acoustic telemetry, have enabled the collection of these data for mobile marine organisms such as sea turtles. The east Pacific green sea turtle Chelonia mydas uses San Diego Bay, CA, a heavily developed ecosystem, as a year-round foraging ground. We used a combination of manual and automated acoustic telemetry from 2009 to 2011 to elucidate the distribution of green turtles throughout South San Diego Bay and to understand their diel behavior. Tracked turtles (n=20) ranged in size from 54.9 to 102.5cm straight carapace length and had fidelity to two sites: the warm-water effluent channel of a waterfront power plant and an eelgrass meadow. Turtles tracked manually during the night were more sedentary (mean swimming speed±SE: 0.38±0.03kmh−1) and generally restricted their activity to waters near the power plant. During the day, turtles swam at higher speeds (0.67±0.07kmh−1) and were mainly found in eelgrass meadows where they are known to forage. Turtles were occasionally found near a shipping terminal, which occurred almost exclusively during the daytime. Turtles in areas of increased boat traffic are at risk of vessel strikes, and future monitoring should investigate the potential for turtle–human interactions in other heavily-used areas of San Diego Bay. Future monitoring should also characterize how turtle behavior may change following the decommissioning of the power plant, which occurred six months before the end of this study.

Effects of off-road vehicle tyre ruts on the beach dispersal of green sea turtle Chelonia mydas hatchlings

The use of off-road vehicles (ORVs) on sandy beaches creates ruts in the sand that may interfere with the beach dispersal of sea turtle hatchlings. The present study investigated the influence of simulated ORV ruts of 3 depths (5, 10 and 15 cm) on the success and speed of green sea turtle Chelonia mydas hatchling dispersal. Almost all hatchlings (91%) were unable to tra- verse a single 15 cm rut, indicating that ruts of this depth are particularly detrimental to hatchling dispersal. Hatchlings had greater success traversing the 5 and 10 cm ruts, although they spent 2.6 and 18.6 times longer to get through a single rut, respectively (compared to the flat sand control path). It took progressively longer to get through subsequent ruts, and 99 and 53% of the hatch- lings crawled along the 10 and 5 cm ruts, respectively, instead of attempting to crawl out of them. It was estimated that if hatchlings had to traverse 100 ORV ruts during dispersal, it would take 1.9 and 25.1 h for 5 and 10 cm deep ruts, respectively. The results from the present study indicate that green sea turtle hatchlings would spend considerable time navigating through ORV ruts, even as shallow as 5 cm, resulting in increased exposure to predation, dehydration and energy expendi- ture during this initial stage of dispersal.

Mitochondrial DNA STR analysis as a tool for studying the green sea turtle (Chelonia mydas) populations: The Mediterranean Sea case study

The Mediterranean population of the green sea turtle Chelonia mydas is critically endangered. Genetic analysis of this population using the ordinary haplotyping system, based on sequence analysis of a segment of the mitochondrial DNA (mtDNA) D-loop (control region), revealed very little variation. The most common haplotype, CM-A13, was observed in all but three individuals in hundreds of samples in previous studies. In search for a more informative marker we sequenced the 3′ of the mitochondrial control region which contains an AT-rich microsatellite. We found a unique pattern that consists of four AT short tandem repeats (STRs) with varying copy numbers. This allowed us to construct a new haplotyping system composed of four different STR sizes for each mtDNA sequence. Our new mitochondrial STR (mtSTR) haplotyping approach revealed 33 different haplotypes within the nesting and stranded sea turtles along the Mediterranean Israeli seashore. The Israeli coast nesting females had 10 different haplotypes that can be used for monitoring and conservation purposes. The mtSTR haplotyping system can clearly assist in fingerprinting of individual turtles. Moreover, it can be used for estimating phylogenetic distances within populations. This case study shows that the mtSTR haplotyping is applicable for the study of global green sea turtle populations and could also be considered as markers of genetic variability in other species.

한국연안의 푸른바다거북(Chelonia mydas) 인공위성표지방류

To investigate the distribution and migrations of sea turtles occurring in Korean waters, an adult female green sea turtle Chelonia mydas was tagged with a satellite transmitter and released at Busan in October 2009. The confirmation was made for the first time that the released green sea turtle migrated back to Korea after visiting Jeju Island and Japan for approximately 9 months. The green sea turtle spent the winter in Jeju and Japan because of low water temperatures in the East Sea and South Sea during winter months, which were not suitable for turtle survival. Compared with an immature green sea turtle that was released at Jeju Island, the adult green showed a markedly different migration pattern, suggesting that juvenile and adult greens move differently because of their peculiar life cycle and their stage of maturity, in addition to responses to temperature changes. Additional satellite tracking with increased representation of species, sexes and sizes of turtles, and regions is required to gather information on the distribution and movements of sea turtles in Korean waters.

Occurrence of Amphiorchis solus (Simha &amp; Chattopadhyaya, 1970) (Digenea: Spirorchiidae) Infecting the Green Turtle Chelonia mydas Linnaeus, 1758 (Testudines: Cheloniidae) in Brazil

Abstract The occurrence of one specimen of Amphiorchis solus (Simha & Chattopadhyaya, 1970) found in the heart of a green sea turtle Chelonia mydas Linnaeus, 1758 from Ceara state, Brazil, is reported. A comparison of the morphology of Amphorchis caborojoensis Fischthal & Acholonu, 1976 and A. solus also is presented. A new geographical distribution of A. solus is reported.

Ecosystem structure and processes at Kaloko Honokohau, focusing on the role of herbivores, including the green sea turtle Chelonia mydas, in reef resilience

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 420:27-44 (2010) - DOI: https://doi.org/10.3354/meps08846 Ecosystem structure and processes at Kaloko Honokōhau, focusing on the role of herbivores, including the green sea turtle Chelonia mydas, in reef resilience Colette C. C. Wabnitz1,*, George Balazs2, Sallie Beavers3, Karen A. Bjorndal4, Alan B. Bolten4, Villy Christensen1, Stacy Hargrove2, Daniel Pauly1 1Fisheries Centre, AERL, University of British Columbia, 2202 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada 2Marine Turtle Research Program, NOAA, National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 2570 Dole Street, Honolulu, Hawai’i 96822-2396, USA 3National Park Service, Kaloko-Honok–ohau National Historical Park, 73-4786 Kanalani St., #14, Kailua Kona, Hawai’i 96740, USA 4Archie Carr Center for Sea Turtle Research, and Department of Biology, PO Box 118525, University of Florida, Gainesville, Florida 32611, USA *Email: colette.wabnitz@gmail.com ABSTRACT: The formal protection of the Hawaiian green turtle Chelonia mydas in the 1970s has led to significant increases in the number of individuals recorded throughout the archipelago. Reduced growth rates and poor body condition of individuals at a number of foraging sites, including Kaloko-Honokoōhau National Historical Park (Kaloko), suggest that some aggregations have reached carrying capacity. To better understand the ecological structure and processes of the reef system at the park, we developed an ecosystem model that synthesized available data on Kaloko for the year 2005 and included 26 groups, spanning the entire trophic web. Model results showed that the combined grazing pressure of the different herbivore functional groups (i.e. reef fish, sea urchins, and green turtles) in Kaloko matched total algal production. Sea urchins exerted the strongest control over algal resources, partly because of their large biomass in park waters. Results confirmed that the Kaloko green turtle aggregation has reached carrying capacity. Green turtles help maintain low algal cover, and thus resilience of reefs in the face of disturbance, and should be explicitly included in studies of ecosystem dynamics on reefs. Our work also provides a ‘current-condition’ baseline for Kaloko, and a valuable tool for the assessment of the future marine ecosystem impacts of projected urban expansion plans around the park. KEY WORDS: Marine turtles · Ecosystem-based management · Ecopath · Coral reef · Herbivory · Phase shift · Nutrient enrichment · Kona coast · Hawaii Full text in pdf format Supplementary material PreviousNextCite this article as: Wabnitz CCC, Balazs G, Beavers S, Bjorndal KA and others (2010) Ecosystem structure and processes at Kaloko Honokōhau, focusing on the role of herbivores, including the green sea turtle Chelonia mydas, in reef resilience. Mar Ecol Prog Ser 420:27-44. https://doi.org/10.3354/meps08846Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 420. Online publication date: December 16, 2010 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2010 Inter-Research.

Persistent organic pollutants in the green sea turtle Chelonia mydas: nesting population variation, maternal transfer, and effects on development

Persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs), have a wide range of toxic effects on humans and wildlife, and have been reported in a number of endangered sea tur- tle populations. The present study screened for POPs in a green sea turtle Chelonia mydas popula- tion in Peninsular Malaysia and investigated the maternal transfer and effects of POPs on embryonic development. At the Ma'Daerah Turtle Sanctuary, blood, eggs and hatchling blood were collected from 11 nesting female C. mydas. Samples were analysed for 83 PCBs, 23 OCPs and 19 PBDEs using gas chromatography with tandem mass spectrometry. The chemical profiles of eggs from individual turtles were significantly different, indicating variable contaminant uptake during foraging. There was evidence of maternal transfer of POPs to eggs and hatchlings, with significant correlations in sum of PCBs (ΣPCB), sum of PBDEs (ΣPBDE), γ-hexachlorocyclohexane (γ-HCH), trans-chlordane and mirex concentrations between maternal blood and eggs (p < 0.05, R 2 < 0.71), between eggs and hatchling blood (p < 0.05, R 2 < 0.83), and between maternal and hatchling blood (p < 0.05, R 2 < 0.61). In addition, there was congener-specific transfer of PCBs with less lipophilic congeners (e.g. PCB 99) more readily transferred to hatchlings than the more lipophilic congeners (e.g. PCBs 180 + 193). There was also a significant correlation between increasing egg POP concentration and decreasing hatchling mass:length ratio. POPs may therefore have subtle effects on the development of C. mydas eggs, which may compromise offshore dispersal and predator avoidance.

Stable isotope discrimination (δ13C and δ15N) between soft tissues of the green sea turtle Chelonia mydas and its diet

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 308:271-278 (2006) - doi:10.3354/meps308271 Stable isotope discrimination (δ13C and δ15N) between soft tissues of the green sea turtle Chelonia mydas and its diet Jeffrey A. Seminoff1,*, T. Todd Jones2, Tomoharu Eguchi1, David R. Jones2, Peter H. Dutton1 1NOAA-National Marine Fisheries Service, Southwest Fisheries Science Center, 8604 La Jolla Shores Drive, La Jolla, California 92037, USA 2Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia V6T 1Z4, Canada *Email: jeffrey.seminoff@noaa.gov ABSTRACT: The foraging ecology and movements of vertebrate species have been increasingly studied via stable isotope analyses of small quantities of body tissues. However, the theoretical and experimental basis of this method remains poorly validated for most taxa despite numerous studies using these techniques in natural systems. In this study, we measured stable carbon and stable nitrogen diet–tissue discrimination (Δdt) in whole blood, red blood cells, blood plasma, and epidermis of 8 captive green turtles Chelonia mydas maintained on a control diet (41% protein, 12% lipids, 4% fiber) for 619 d. During the course of the study, mean straight carapace length increased from 45.2 ± 1.2 to 53.7 ± 2.1 cm, whereas mean body mass increased from 11.7 ± 0.7 to 19.9 ± 2.2 kg. Both diet and tissue isotope values remained constant throughout the study, indicating that diet–tissue equilibrium had been achieved. Whereas Δdt13C ranged from –1.11‰ (red blood cells) to +0.17‰ (epidermis), Δdt15N ranged from +0.22‰ (red blood cells) to +2.92‰ (blood plasma). These results contrast with the widely accepted discrimination factors of 0 to 1‰ for δ13C and 3 to 5‰ for δ15N. Comprising the initial enrichment factors available for green turtles, these data will be useful in future interpretations of field isotopic values for this species. KEY WORDS: Carbon · Chelonidae · Ectotherm · Fractionation · Isotope enrichment · Nitrogen · Reptilia Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 308. Online publication date: February 16, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.