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Justin R. Perrault - One of the best experts on this subject based on the ideXlab platform.
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evidence of accumulation and elimination of inorganic contaminants from the lachrymal salt glands of Leatherback Sea Turtles dermochelys coriacea
Chemosphere, 2019Co-Authors: Justin R. Perrault, Andreas F Lehner, John P Buchweitz, Annie PagekarjianAbstract:Abstract Plasma osmolalities of marine vertebrates are generally lower than the surrounding medium; therefore, marine organisms must cope with the osmoregulatory challenges of life in a salty environment. The salt glands serve to maintain osmotic and ionic homeostasis in a number of lower marine vertebrates. One marine reptile, the Leatherback Sea Turtle ( Dermochelys coriacea ), ingests excessive amounts of salts due to their diet of gelatinous zooplankton. Outside of the normal osmoregulatory function of the salt gland, little reSearch has been conducted on contaminant accumulation and excretion in this organ. Here, we established arsenic, cadmium, lead, mercury, and selenium concentrations in red blood cells (RBCs) and salt gland secretions (SGSs) of nesting Leatherbacks. We also collected salt glands from different life stage classes of dead stranded Leatherbacks from the western Atlantic Ocean to determine if inorganic contaminants accumulate in this organ. Using non-metric multidimensional scaling and regression analyses, we determined that RBC and SGS inorganic contaminant concentrations were not correlated. Additionally, RBCs showed significantly higher concentrations of these contaminants in comparison to SGSs, likely due to the affinity of inorganic contaminants for the heme group of RBCs. Lastly, we found that salt gland cadmium and mercury concentrations tended to increase with increasing curved carapace length (CCL) in stranded Leatherbacks. Our results indicate that different physiological mechanisms determine the distribution of inorganic contaminants in blood and SGSs. Increases in salt gland contaminant concentrations with increasing CCL suggest this organ as a potential target for accumulation.
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nesting Leatherback Sea Turtle dermochelys coriacea packed cell volumes indicate decreased foraging during reproduction
Marine Biology, 2016Co-Authors: Annie Pagekarjian, Justin R. Perrault, Debra L. MillerAbstract:Leatherback Sea Turtles (Dermochelys coriacea) are hypothesized to be capital breeders, whereby they forage little to none during the nesting Season. The capital breeding hypothesis can be tested in marine Turtles using physiological measures of health, which are much less expensive than studies that use satellite tags or other physiological monitoring equipment to make inferences about behavior and foraging status during the nesting Season. In this study, we analyzed packed cell volumes (PCVs), a simple and inexpensive, hematologic health parameter, in nesting Leatherback Turtles from St. Croix, U.S. Virgin Islands (17°40′40″N, 64°54′0″W) across the nesting Season (April–July 2009) in an effort to determine foraging status. We found that PCV in nesting females significantly declined using two longitudinal measures: nest number and level of reproductive effort. We also found that PCVs of remigrants were significantly higher in comparison with neophytes, suggesting that experience in reproductive activities (e.g., migration, breeding, nesting) might increase foraging success on feeding grounds. Lastly, we found that Leatherbacks with a greater reproductive output had significantly higher PCVs. While the northwest Atlantic Leatherback population is evaluated as least concern by the IUCN, Pacific Leatherbacks are critically endangered. The assumed behaviors of Turtles from this study provide insight into reproductive strategies and energy reserves in all marine Turtle populations. Thus, the results presented here are applicable to (1) veterinarians, rehabilitation facilities, and conservationists and (2) other more vulnerable marine Turtle populations.
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Maternal Health Status Correlates with Nest Success of Leatherback Sea Turtles (Dermochelys coriacea) from Florida
2016Co-Authors: Justin R. Perrault, Debra L. Miller, Larry J Thompson, Chris Johnson, Erica Eads, Anita Merrill, Jeanette WynekenAbstract:Of the seven Sea Turtle species, the critically endangered Leatherback Sea Turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60–70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in Leatherback Sea Turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian Leatherbacks were low during the study period (2007–2008 nesting Seasons), a trend common in most nesting Leatherback populations (average global hatching success =,50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol
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mercury and selenium ingestion rates of atlantic Leatherback Sea Turtles dermochelys coriacea a cause for concern in this species
Marine Environmental Research, 2014Co-Authors: Justin R. PerraultAbstract:Abstract Bodily accumulation of certain toxic elements can cause physiologic harm to marine organisms and be detrimental to their health and survival. The Leatherback Sea Turtle (Dermochelys coriacea) is a broadly distributed marine reptile capable of consuming hundreds of kilograms of gelatinous zooplankton each day. Little is known about toxicants present in these prey items. Specifically, mercury is a known neurotoxin with no known essential function, while selenium detoxifies bodily mercury, but can be toxic at elevated concentrations. I collected 121 Leatherback prey items (i.e., gelatinous zooplankton) from known Leatherback foraging grounds and sampled the esophagus and stomach contents of stranded Turtles. All samples were analyzed for total mercury and selenium. Additionally, two prey items and three liver samples were analyzed for methylmercury, the most toxic form of the element. Total mercury concentrations in prey items ranged from 0.2 to 17 ppb, while selenium concentrations ranged from
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maternal health status correlates with nest success of Leatherback Sea Turtles dermochelys coriacea from florida
PLOS ONE, 2012Co-Authors: Justin R. Perrault, Debra L. Miller, Larry J Thompson, Chris Johnson, Erica Eads, Anita Merrill, Jeanette WynekenAbstract:: Of the seven Sea Turtle species, the critically endangered Leatherback Sea Turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60-70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in Leatherback Sea Turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian Leatherbacks were low during the study period (2007-2008 nesting Seasons), a trend common in most nesting Leatherback populations (average global hatching success = ∼50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol, creatinine, and phosphorus. Our results suggest that in Leatherbacks, physiological parameters correlate with hatching success and emergence success of their nests. We conclude that long-term and comparative studies are needed to determine if certain individuals produce nests with lower hatching success and emergence success than others, and if those individuals with evidence of chronic suboptimal health have lower reproductive success.
Debra L. Miller - One of the best experts on this subject based on the ideXlab platform.
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nesting Leatherback Sea Turtle dermochelys coriacea packed cell volumes indicate decreased foraging during reproduction
Marine Biology, 2016Co-Authors: Annie Pagekarjian, Justin R. Perrault, Debra L. MillerAbstract:Leatherback Sea Turtles (Dermochelys coriacea) are hypothesized to be capital breeders, whereby they forage little to none during the nesting Season. The capital breeding hypothesis can be tested in marine Turtles using physiological measures of health, which are much less expensive than studies that use satellite tags or other physiological monitoring equipment to make inferences about behavior and foraging status during the nesting Season. In this study, we analyzed packed cell volumes (PCVs), a simple and inexpensive, hematologic health parameter, in nesting Leatherback Turtles from St. Croix, U.S. Virgin Islands (17°40′40″N, 64°54′0″W) across the nesting Season (April–July 2009) in an effort to determine foraging status. We found that PCV in nesting females significantly declined using two longitudinal measures: nest number and level of reproductive effort. We also found that PCVs of remigrants were significantly higher in comparison with neophytes, suggesting that experience in reproductive activities (e.g., migration, breeding, nesting) might increase foraging success on feeding grounds. Lastly, we found that Leatherbacks with a greater reproductive output had significantly higher PCVs. While the northwest Atlantic Leatherback population is evaluated as least concern by the IUCN, Pacific Leatherbacks are critically endangered. The assumed behaviors of Turtles from this study provide insight into reproductive strategies and energy reserves in all marine Turtle populations. Thus, the results presented here are applicable to (1) veterinarians, rehabilitation facilities, and conservationists and (2) other more vulnerable marine Turtle populations.
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Maternal Health Status Correlates with Nest Success of Leatherback Sea Turtles (Dermochelys coriacea) from Florida
2016Co-Authors: Justin R. Perrault, Debra L. Miller, Larry J Thompson, Chris Johnson, Erica Eads, Anita Merrill, Jeanette WynekenAbstract:Of the seven Sea Turtle species, the critically endangered Leatherback Sea Turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60–70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in Leatherback Sea Turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian Leatherbacks were low during the study period (2007–2008 nesting Seasons), a trend common in most nesting Leatherback populations (average global hatching success =,50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol
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maternal health status correlates with nest success of Leatherback Sea Turtles dermochelys coriacea from florida
PLOS ONE, 2012Co-Authors: Justin R. Perrault, Debra L. Miller, Larry J Thompson, Chris Johnson, Erica Eads, Anita Merrill, Jeanette WynekenAbstract:: Of the seven Sea Turtle species, the critically endangered Leatherback Sea Turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60-70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in Leatherback Sea Turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian Leatherbacks were low during the study period (2007-2008 nesting Seasons), a trend common in most nesting Leatherback populations (average global hatching success = ∼50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol, creatinine, and phosphorus. Our results suggest that in Leatherbacks, physiological parameters correlate with hatching success and emergence success of their nests. We conclude that long-term and comparative studies are needed to determine if certain individuals produce nests with lower hatching success and emergence success than others, and if those individuals with evidence of chronic suboptimal health have lower reproductive success.
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why are hatching and emergence success low mercury and selenium concentrations in nesting Leatherback Sea Turtles dermochelys coriacea and their young in florida
Marine Pollution Bulletin, 2011Co-Authors: Justin R. Perrault, Jeanette Wyneken, Larry J Thompson, Chris Johnson, Debra L. MillerAbstract:Leatherback Sea Turtles (Dermochelys coriacea) have low hatching and emergence success compared to other Sea Turtle species. Postmortem examinations of hatchlings showed degeneration of heart and skeletal muscle that was similar to that found in other neonates with selenium deficient mothers. Selenium deficiency can result from elevated concentrations of bodily mercury. Ingested mercury is detoxified by the liver through mercury–selenium compound formation. In animals persistently exposed to mercury, the liver’s ability to detoxify this element may decrease, especially if dietary selenium is insufficient. We measured mercury and selenium concentrations in nesting female Leatherbacks and their hatchlings from Florida and compared the levels to hatching and emergence success. Both liver selenium and the liver selenium-to-mercury ratio positively correlated with Leatherback hatching and emergence success. This study provides the first evidence for the roles of mercury and selenium in explaining low reproductive success in a globally imperiled species, the Leatherback Sea Turtle.
Jeanette Wyneken - One of the best experts on this subject based on the ideXlab platform.
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Maternal Health Status Correlates with Nest Success of Leatherback Sea Turtles (Dermochelys coriacea) from Florida
2016Co-Authors: Justin R. Perrault, Debra L. Miller, Larry J Thompson, Chris Johnson, Erica Eads, Anita Merrill, Jeanette WynekenAbstract:Of the seven Sea Turtle species, the critically endangered Leatherback Sea Turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60–70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in Leatherback Sea Turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian Leatherbacks were low during the study period (2007–2008 nesting Seasons), a trend common in most nesting Leatherback populations (average global hatching success =,50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol
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Leatherbacks swimming in silico modeling and verifying their momentum and heat balance using computational fluid dynamics
PLOS ONE, 2014Co-Authors: Peter N Dudley, Todd T Jones, Jeanette Wyneken, Riccardo Bonazza, Warren P PorterAbstract:As global temperatures increase throughout the coming decades, species ranges will shift. New combinations of abiotic conditions will make predicting these range shifts difficult. Biophysical mechanistic niche modeling places bounds on an animal’s niche through analyzing the animal’s physical interactions with the environment. Biophysical mechanistic niche modeling is flexible enough to accommodate these new combinations of abiotic conditions. However, this approach is difficult to implement for aquatic species because of complex interactions among thrust, metabolic rate and heat transfer. We use contemporary computational fluid dynamic techniques to overcome these difficulties. We model the complex 3D motion of a swimming neonate and juvenile Leatherback Sea Turtle to find power and heat transfer rates during the stroke. We combine the results from these simulations and a numerical model to accurately predict the core temperature of a swimming Leatherback. These results are the first steps in developing a highly accurate mechanistic niche model, which can assists paleontologist in understanding biogeographic shifts as well as aid contemporary species managers about potential range shifts over the coming decades.
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maternal health status correlates with nest success of Leatherback Sea Turtles dermochelys coriacea from florida
PLOS ONE, 2012Co-Authors: Justin R. Perrault, Debra L. Miller, Larry J Thompson, Chris Johnson, Erica Eads, Anita Merrill, Jeanette WynekenAbstract:: Of the seven Sea Turtle species, the critically endangered Leatherback Sea Turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60-70 for most values) of baseline blood parameters (protein electrophoresis, hematology, plasma biochemistry) for this species to date. Hematologic, protein electrophoretic and biochemical values are important tools that can provide information regarding the physiological condition of an individual and population health as a whole. It has been proposed that the health of nesting individuals affects their reproductive output. In order to establish correlations with low reproductive success in Leatherback Sea Turtles from Florida, we compared maternal health indices to hatching success and emergence success of their nests. As expected, hatching success (median = 57.4%) and emergence success (median = 49.1%) in Floridian Leatherbacks were low during the study period (2007-2008 nesting Seasons), a trend common in most nesting Leatherback populations (average global hatching success = ∼50%). One protein electrophoretic value (gamma globulin protein) and one hematologic value (red blood cell count) significantly correlated with hatching success and emergence success. Several maternal biochemical parameters correlated with hatching success and/or emergence success including alkaline phosphatase activity, blood urea nitrogen, calcium, calcium:phosphorus ratio, carbon dioxide, cholesterol, creatinine, and phosphorus. Our results suggest that in Leatherbacks, physiological parameters correlate with hatching success and emergence success of their nests. We conclude that long-term and comparative studies are needed to determine if certain individuals produce nests with lower hatching success and emergence success than others, and if those individuals with evidence of chronic suboptimal health have lower reproductive success.
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experimental study of dune vegetation impact and control on Leatherback Sea Turtle dermochelys coriacea nests
Endangered Species Research, 2011Co-Authors: Jeremy R Conrad, Jeanette Wyneken, Jeanne Garner, Steve GarnerAbstract:The Leatherback Sea Turtle Dermochelys coriacea is a Critically Endangered species that nests on oceanic beaches. Natural disturbance cycles of erosion and accretion maintain nest- ing habitat on these beaches by controlling dune vegetation and sand quality. The nesting beach at Sandy Point National Wildlife Refuge in St. Croix, US Virgin Islands, is designated 'critical habi- tat' for Leatherback Turtles by the US Fish and Wildlife Service. It harbors the largest nesting pop- ulation (>800 females) in the USA. It is an important rookery for Atlantic Leatherback recovery efforts. For the past 30 yr, the beach has been continuously monitored and managed in order to increase hatchling recruitment and conservation. Our study highlights how a multiyear change in the natural disturbance cycle has affected dune plant growth and Leatherback production at this beach. Reduced summer erosion relaxed natural control of Ipomoea pes-caprae, a native dune plant, allowing its Seaward spread to cover >75% of the nesting beach. This spread of vegetation led to both direct and indirect interactions between nesting Leatherbacks and I. pes-caprae. Because the beach is managed in order to protect Leatherback nests, a dune vegetation control plan was needed. We measured the effects of 3 vegetation management options on nest success: herbicide treatment, aboveground mechanical removal, and undisturbed vegetation. These treat- ments were compared to nest success at a non-vegetated control site. We found that the spread of I. pes-caprae reduced nesting habitat and nest productivity. Aboveground vegetation treatment did not control root growth into nests. We discuss possible vegetation management strategies to improve Leatherback nesting habitat quality and maximize nest productivity while minimizing anthropogenic disturbance to the natural beach dynamics.
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why are hatching and emergence success low mercury and selenium concentrations in nesting Leatherback Sea Turtles dermochelys coriacea and their young in florida
Marine Pollution Bulletin, 2011Co-Authors: Justin R. Perrault, Jeanette Wyneken, Larry J Thompson, Chris Johnson, Debra L. MillerAbstract:Leatherback Sea Turtles (Dermochelys coriacea) have low hatching and emergence success compared to other Sea Turtle species. Postmortem examinations of hatchlings showed degeneration of heart and skeletal muscle that was similar to that found in other neonates with selenium deficient mothers. Selenium deficiency can result from elevated concentrations of bodily mercury. Ingested mercury is detoxified by the liver through mercury–selenium compound formation. In animals persistently exposed to mercury, the liver’s ability to detoxify this element may decrease, especially if dietary selenium is insufficient. We measured mercury and selenium concentrations in nesting female Leatherbacks and their hatchlings from Florida and compared the levels to hatching and emergence success. Both liver selenium and the liver selenium-to-mercury ratio positively correlated with Leatherback hatching and emergence success. This study provides the first evidence for the roles of mercury and selenium in explaining low reproductive success in a globally imperiled species, the Leatherback Sea Turtle.
Michelle M Dennis - One of the best experts on this subject based on the ideXlab platform.
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Leatherback Sea Turtle dermochelys coriacea hatch success and essential and nonessential metals in eggs and embryos from nests in st kitts 2015
Marine Pollution Bulletin, 2020Co-Authors: Michelle M Dennis, Kristine Hill, Anne Conan, Robert H Poppenga, Sabine Hargrave, Victoria Maroun, Kimberly M StewartAbstract:Abstract Northwest Atlantic Leatherback Sea Turtles (Dermochelys coriacea) are endangered and low hatch success limits potential for population recovery. We examined essential and nonessential metal concentrations in 43 eggs from nests on St. Kitts to determine if there was a relationship with hatch success. Whole homogenized embryos and undeveloped eggs contained detectable concentrations of arsenic, barium, copper, iron, selenium, vanadium, and zinc, but not beryllium, cadmium, chromium, cobalt, lead, mercury, molybdenum, and thallium. Of detected metals, only vanadium concentrations negatively correlated with hatch success (P = 0.01). Manganese and vanadium were associated with pneumonia occurring in the nest, and arsenic with renal mineralization. This study adds to the knowledge regarding baseline values for environmental contaminants in Sea Turtles, supporting the trend that Leatherback eggs have relatively low concentrations of toxic metals, lacking a strong relationship with hatch success, and normally contain the essential elements copper, iron, selenium, and zinc.
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Leatherback Sea Turtle dermochelys coriacea embryo and hatchling pathology in grenada with comparison to st kitts
Chelonian Conservation and Biology, 2020Co-Authors: Esther Choi, Kate E Charles, Kester L Charles, Kimberly M Stewart, Clare E Morrall, Michelle M DennisAbstract:Globally, the hatch success of Leatherback Sea Turtles (Dermochelys coriacea) is much lower than any other Sea Turtle species. Causes of embryonic mortality, a contributing factor to the low hatch success of the species, are poorly understood. Muscle necrosis, renal mineralization, and bacterial pneumonia are prevalent among embryos and hatchlings in St. Kitts, where hatch success is much lower (<∼ 20%) than the global average (∼ 50%), yet the significance of these conditions in the wider region is unknown. The objective of this study was to describe the pathology of hatchlings and embryos in Grenada as a comparison population for St. Kitts. In 2017, 20 hatchlings, 6 pipped hatchlings, 35 late stage embryos, and 5 early stage embryos were sampled for comprehensive postmortem examination from 12 Leatherback nests on Levera Beach, Grenada and 2 nests on St. Kitts. Pathology affected 71% of nests and 44% of individuals from Grenada and 100% of nests and 56% of individuals from St. Kitts. Lesions observed in both populations included skeletal muscle degeneration and necrosis (19%), bronchopneumonia (8%), and renal tubular degeneration (5%) while chorioallantoitis (17%) and mycotic dermatitis (5%) were only observed in Grenada. Gonads were histologically classified as female in all instances (n = 60), suggestive of high incubation temperatures in nests at both locations. Further study is needed to find interventions that reduce the prevalence of perinatal pathology and to identify the basis for the large proportion of eggs that fail to develop as well as embryos that die without significant pathology.
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pathology of Leatherback Sea Turtle dermochelys coriacea embryos and hatchlings from nests in st kitts west indies 2015 16
Journal of Wildlife Diseases, 2019Co-Authors: Kristine Hill, Kimberly M Stewart, Sreekumari Rajeev, Anne Conan, Michelle M DennisAbstract:Sustained hatchling production is a priority for Leatherback Sea Turtle (Dermochelys coriacea) conservation. Yet the species is challenged by notoriously low hatch success, much lower than other species of Sea Turtles, and the result of a high rate of embryo mortality for which the causes are not understood. The aim of our study was to describe the pathology of embryos and dead-in-nest hatchlings, to help understand the basis for low hatch success in St. Kitts, West Indies. We surveyed two Leatherback nesting beaches, Keys and North Friars, in 2015–16. Pathology was present in 38% (32 of 84) of individuals, including renal mineralization (24%, 20 of 83), bacterial pneumonia (12%, 10 of 82), and skeletal muscle necrosis (7%, 6 of 84). Renal mineralization was seen in all stages of development that we examined and was associated with cardiac mineralization in two cases. Bacterial pneumonia affected dead-in-nest hatchlings and late-stage embryos and involved 40% (6 of 15) of nests evaluated, all laid by different mothers. Hematopoiesis was consistently observed in the liver, lung, kidneys, and heart. Gonad was histologically classified as female in 100% (68 of 68) of individuals examined. Rathke's gland was identified in the axillary musculature of 51 individuals, which has not previously been described in Leatherbacks. Bacterial pneumonia and renal mineralization were presumed to be significant causes of death in Leatherback embryos and hatchlings in St. Kitts. Overrepresentation of females in our study suggested high incubation temperatures in the nests.
Kimberly M Stewart - One of the best experts on this subject based on the ideXlab platform.
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Leatherback Sea Turtle dermochelys coriacea hatch success and essential and nonessential metals in eggs and embryos from nests in st kitts 2015
Marine Pollution Bulletin, 2020Co-Authors: Michelle M Dennis, Kristine Hill, Anne Conan, Robert H Poppenga, Sabine Hargrave, Victoria Maroun, Kimberly M StewartAbstract:Abstract Northwest Atlantic Leatherback Sea Turtles (Dermochelys coriacea) are endangered and low hatch success limits potential for population recovery. We examined essential and nonessential metal concentrations in 43 eggs from nests on St. Kitts to determine if there was a relationship with hatch success. Whole homogenized embryos and undeveloped eggs contained detectable concentrations of arsenic, barium, copper, iron, selenium, vanadium, and zinc, but not beryllium, cadmium, chromium, cobalt, lead, mercury, molybdenum, and thallium. Of detected metals, only vanadium concentrations negatively correlated with hatch success (P = 0.01). Manganese and vanadium were associated with pneumonia occurring in the nest, and arsenic with renal mineralization. This study adds to the knowledge regarding baseline values for environmental contaminants in Sea Turtles, supporting the trend that Leatherback eggs have relatively low concentrations of toxic metals, lacking a strong relationship with hatch success, and normally contain the essential elements copper, iron, selenium, and zinc.
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Leatherback Sea Turtle dermochelys coriacea embryo and hatchling pathology in grenada with comparison to st kitts
Chelonian Conservation and Biology, 2020Co-Authors: Esther Choi, Kate E Charles, Kester L Charles, Kimberly M Stewart, Clare E Morrall, Michelle M DennisAbstract:Globally, the hatch success of Leatherback Sea Turtles (Dermochelys coriacea) is much lower than any other Sea Turtle species. Causes of embryonic mortality, a contributing factor to the low hatch success of the species, are poorly understood. Muscle necrosis, renal mineralization, and bacterial pneumonia are prevalent among embryos and hatchlings in St. Kitts, where hatch success is much lower (<∼ 20%) than the global average (∼ 50%), yet the significance of these conditions in the wider region is unknown. The objective of this study was to describe the pathology of hatchlings and embryos in Grenada as a comparison population for St. Kitts. In 2017, 20 hatchlings, 6 pipped hatchlings, 35 late stage embryos, and 5 early stage embryos were sampled for comprehensive postmortem examination from 12 Leatherback nests on Levera Beach, Grenada and 2 nests on St. Kitts. Pathology affected 71% of nests and 44% of individuals from Grenada and 100% of nests and 56% of individuals from St. Kitts. Lesions observed in both populations included skeletal muscle degeneration and necrosis (19%), bronchopneumonia (8%), and renal tubular degeneration (5%) while chorioallantoitis (17%) and mycotic dermatitis (5%) were only observed in Grenada. Gonads were histologically classified as female in all instances (n = 60), suggestive of high incubation temperatures in nests at both locations. Further study is needed to find interventions that reduce the prevalence of perinatal pathology and to identify the basis for the large proportion of eggs that fail to develop as well as embryos that die without significant pathology.
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pathology of Leatherback Sea Turtle dermochelys coriacea embryos and hatchlings from nests in st kitts west indies 2015 16
Journal of Wildlife Diseases, 2019Co-Authors: Kristine Hill, Kimberly M Stewart, Sreekumari Rajeev, Anne Conan, Michelle M DennisAbstract:Sustained hatchling production is a priority for Leatherback Sea Turtle (Dermochelys coriacea) conservation. Yet the species is challenged by notoriously low hatch success, much lower than other species of Sea Turtles, and the result of a high rate of embryo mortality for which the causes are not understood. The aim of our study was to describe the pathology of embryos and dead-in-nest hatchlings, to help understand the basis for low hatch success in St. Kitts, West Indies. We surveyed two Leatherback nesting beaches, Keys and North Friars, in 2015–16. Pathology was present in 38% (32 of 84) of individuals, including renal mineralization (24%, 20 of 83), bacterial pneumonia (12%, 10 of 82), and skeletal muscle necrosis (7%, 6 of 84). Renal mineralization was seen in all stages of development that we examined and was associated with cardiac mineralization in two cases. Bacterial pneumonia affected dead-in-nest hatchlings and late-stage embryos and involved 40% (6 of 15) of nests evaluated, all laid by different mothers. Hematopoiesis was consistently observed in the liver, lung, kidneys, and heart. Gonad was histologically classified as female in 100% (68 of 68) of individuals examined. Rathke's gland was identified in the axillary musculature of 51 individuals, which has not previously been described in Leatherbacks. Bacterial pneumonia and renal mineralization were presumed to be significant causes of death in Leatherback embryos and hatchlings in St. Kitts. Overrepresentation of females in our study suggested high incubation temperatures in the nests.
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detection of salmonella enterica serovar montevideo and newport in free ranging Sea Turtles and beach sand in the caribbean and persistence in sand and Seawater microcosms
Zoonoses and Public Health, 2017Co-Authors: A K Ives, Kimberly M Stewart, Elizabeth Antaki, Stewart Francis, Michele T Jayrussell, Fortune Sithole, Michael T Kearney, Matt J Griffin, Esteban SotoAbstract:Summary Salmonellae are Gram-negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non-typhoidal Salmonella enterica in the nesting and foraging populations of Sea Turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting Leatherback Sea Turtles compared with foraging green and hawksbill Sea Turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 Leatherback Sea Turtle samples. Salmonella DNA was detected in one hawksbill Turtle, but viable isolates were not recovered from any hawksbill Sea Turtles. No Salmonella was detected in green Sea Turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive-element palindromic PCR (rep-PCR) fingerprint analysis and pulsed-field gel electrophoresis of the 2014 isolates from Turtles and sand as well as archived Salmonella isolates recovered from Leatherback Sea Turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory-controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32 days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free-ranging marine reptiles and the potential public health risks associated with human interactions with these animals in the Caribbean.