Spatial characterization of a foraging area for immature hawksbill turtles (Eretmochelys imbricata) in Yucatan, Mexico

2007 ◽  
Vol 28 (3) ◽  
pp. 337-346 ◽  
Author(s):  
María de los Ángeles Liceaga-Correa ◽  
Eduardo Cuevas ◽  
Mauricio Garduño-Andrade

AbstractThe submarine habitats in the Rio Lagartos Sea Turtle Sanctuary, Mexico, are an important feeding and development area for juvenile Hawksbill turtles (Eretmochelys imbricata). The characterization of these critical habitats is an important and urgent issue to attend for the conservation of this species in Mexico. The objective of this study is to identify, locate and describe the marine benthic habitats in this area, and explain the distribution of the juvenile Hawksbill turtles in the study area. We used submarine techniques such as videotransects and spot checks to characterize the bottom types in the area, and geostatistic techniques to elaborate thematic maps of the different benthic components, integrating all of them into a GIS. We obtained the bottom type map with eight submarine habitats at different depth ranges. We found juvenile Hawksbill turtles distributed mainly on hard bottom sites covered by octocorals, such as Pseudopterogorgia, and sponges of the genera Chondrilla and Spheciospongia. We estimated habitat ranges for the captured turtles and the bottom types occupied by them, then we calculated the distribution densities of juvenile Hawksbill turtles by bottom type. We concluded that the combination of spatial techniques and multivariate statistics is efficient for mapping the marine bottom types in the area, and recommend the generation of specific conservation strategies to protect this area because of the natural marine resources and process ocurring in it.

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253916
Author(s):  
Chelsea E. Clyde-Brockway ◽  
Christina R. Ferreira ◽  
Elizabeth A. Flaherty ◽  
Frank V. Paladino

In this study, we applied multiple reaction monitoring (MRM)-profiling to explore the relative ion intensity of lipid classes in plasma samples from sea turtles in order to profile lipids relevant to sea turtle physiology and investigate how dynamic ocean environments affect these profiles. We collected plasma samples from foraging green (Chelonia mydas, n = 28) and hawksbill (Eretmochelys imbricata, n = 16) turtles live captured in North Pacific Costa Rica in 2017. From these samples, we identified 623 MRMs belonging to 10 lipid classes (sphingomyelin, phosphatidylcholine, free fatty acid, cholesteryl ester, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, phosphatidylethanolamine, ceramide, and triacylglyceride) and one metabolite group (acyl-carnitine) present in sea turtle plasma. The relative ion intensities of most lipids (80%) were consistent between species, across seasons, and were not correlated to body size or estimated sex. Of the differences we observed, the most pronounced was the differences in relative ion intensity between species. We identified 123 lipids that had species-specific relative ion intensities. While some of this variability is likely due to green and hawksbill turtles consuming different food items, we found indications of a phylogenetic component as well. Of these, we identified 47 lipids that varied by season, most belonging to the structural phospholipid classes. Overall, more lipids (n = 39) had higher relative ion intensity in the upwelling (colder) season compared to the non-upwelling season (n = 8). Further, we found more variability in hawksbill turtles than green turtles. Here, we provide the framework in which to apply future lipid profiling in the assessment of health, physiology, and behavior in endangered sea turtles.


Author(s):  
Ricardo Andrés Sarmiento-Devia ◽  
Guiomar Aminta Jaúregui-Romero ◽  
Adolfo Sanjuan-Muñoz

Headstarting is a recovery strategy for sea turtle populations. It requires captive handling of hatchlings, which are transferred from nesting beaches with low percentages of hatching success. Providing adequate nutritional resources for hatchlings is costly but important, as it influences growth rates of young turtles. Assessing the potential of commercial diets as option for promoting healthy growth and reducing the costs of maintenance for captive Hawksbill Turtles, we evaluated the viability of two commercial feeds on the growth rates of the Hawksbill Turtle (Eretmochelys imbricata). We fed turtles to satiation twice a day between the sixth and tenth month of age. Individuals fed with fish flour meal (n=20) exhibited average body mass and straight carapace length (SCL) growth rates of 2.45±1.39 g.day-1 and 0.04±0.02cm.day-1, respectively. The turtles fed with squid flour meal (n =13) displayed growth rates of 3.35±1.11 g.day-1 and 0.04±0.01 cm.day-1. These differences, associated with the low avidity of the specimens for these pellets, may be due to the food characteristics, particularly the size, flotation capability and palatability of the food. However, the presence of amino acids and vitamins in these compounds, and their low cost, can make them viable as a supplementary item suggesting the use of commercial foods only as a dietary supplement.


2017 ◽  
Author(s):  
Aubrey M. Tauer ◽  
Michael J. Liles ◽  
Sofía Chavarría ◽  
Melissa Valle ◽  
Sada Amaya ◽  
...  

AbstractSea 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.


10.1645/20-54 ◽  
2021 ◽  
Vol 107 (2) ◽  
Author(s):  
Daniel M. Fitzpatrick ◽  
Monica A. Tetnowski ◽  
Thomas G. Rosser ◽  
Rhonda D. Pinckney ◽  
David P. Marancik ◽  
...  

1999 ◽  
Vol 77 (9) ◽  
pp. 1465-1473 ◽  
Author(s):  
Matthew H Godfrey ◽  
Adriana F D'Amato ◽  
Maria  Marcovaldi ◽  
N Mrosovsky

Like all other species of sea turtle, the hawksbill turtle (Eretmochelys imbricata) exhibits temperature-dependent sexual differentiation, with high incubation temperatures producing females and low temperatures producing males. Relatively little is known about the sex ratios of hatchlings produced by nesting populations of hawksbill turtles. Here we estimate the overall seasonal sex ratios of hatchling hawksbill turtles produced in Bahia, Brazil, during 6 nesting seasons, based on incubation durations, pivotal temperature, and pivotal incubation duration. The overall sex ratio of hatchlings produced in Bahia from 1991-1992 through 1996-1997 was estimated to be >90% female, which is more female-biased than estimated sex ratios of hatchling loggerhead turtles from Bahia and Florida, U.S.A. The biological and conservation implications of skewed sex ratios are discussed.


2021 ◽  
Vol 9 ◽  
Author(s):  
Javad Loghmannia ◽  
Ali Nasrolahi ◽  
Mohsen Rezaie-Atagholipour ◽  
Bahram H. Kiabi

Sea turtle epibionts can provide insights into the hosts' habitat use. However, at present, there is a lack of information on sea turtle epibiont communities in many locations worldwide. Here, we describe the epibiont communities of 46 hawksbill turtles (Eretmochelys imbricata) in the Persian Gulf. Specifically, we sampled 28 turtles from the Dayyer-Nakhiloo National Park (DNNP) in the northern Gulf and 18 turtles from Shibderaz beach in the Strait of Hormuz. A total of 54 macro, meio, and micro-epibiont taxa were identified, including 46 taxa from Shibderaz and 29 taxa from DNNP. The barnacles Chelonibia testudinaria and Platylepas hexastylos, as well as harpacticoid copepods and Rotaliid foraminifers, had the highest frequency of occurrence found on almost all turtle individuals. Harpacticoids were the most abundant epizoic taxa (19.55 ± 3.9 ind. per 9 cm2) followed by forams (Quinqueloculina spp.: 6.25 ± 1.5 ind. per 9 cm2 and Rotaliids: 6.02 ± 1.3 ind. per 9 cm2). Our results showed significant differences between the study sites in the composition of micro and macro-epibiont communities found on hawksbill turtles. We speculate that the differences in epibiont communities were largely influenced by local environmental conditions.


2020 ◽  
Vol 48 (1) ◽  
pp. 114-130 ◽  
Author(s):  
Estefania Méndez-Salgado ◽  
Didiher Chacón-Chaverri ◽  
Luis G. Fonseca ◽  
Jeffrey A. Seminoff

Hawksbill turtles (Eretmochelys imbricata), considered Critically Endangered, have several small populations in the Eastern Pacific (EP). Knowledge about their diet and habitat use can aid in developing conservation strategies and promoting population recovery in the region. Although considered a spongivore in the Caribbean, data from the EP region indicate that hawksbills consume a wide array of prey species, including angiosperms. We used two approaches to study the diet of hawksbills at Golfo Dulce, Costa Rica: oesophageal lavage and stable isotope (δ13C, δ15N) analysis of bulk skin tissue and blood plasma. Lavage samples collected from 41 turtles revealed macroalgae as the predominant diet item (Rw = 20.22), followed by sea snails and excavating worms. Stable isotope values for blood plasma from 44 turtles ranged from -23.0‰ to -15.7‰ for δ13C and 6.9‰ to 10.4‰ for δ15N, whereas values for skin tissue were -20.4‰ to -13.9‰ and 9.3‰ to 11.0‰ for δ13C and δ15N, respectively. We compared these isotope values with those of five potential prey groups (sponge, sea snail, excavating worm, mangrove, macroalgae) using a multisource stable isotope mixing model analysis in R (SIAR). Our results indicated that multiple prey resources are important for hawksbills in Golfo Dulce, where sea snails, sponges and excavating worms contributed up to 63% of the assimilated diet per individual, and mangrove and macroalgae up to 50%. These data show that hawksbills in Golfo Dulce, and perhaps the wider EP region, are omnivorous, underscoring the importance for considering alternative habitats, aside of coral reefs, for its management and restoration.


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