Data on Sea turtle relative abundance in nearshore waters adjacent to the Mississippi River delta, Gulf of Mexico, United States.

We measured the relative abundance of sea turtles using standardized transect surveys conducted during the summer and fall of 2013 in neritic waters surrounding the Mississippi River delta in Louisiana, USA. Data comprise sea turtle locations, observation circumstances, and environmental covariates recorded at the beginning of each transect and at the time of each turtle observation. Turtles were recorded by species and size class, as well as location in the water column and the distance the turtle was from the transect line. Transects were performed on an 8.2 meter vessel with two observers atop a 4.5 meter elevated platform, with vessel speed standardized at ∼15 km/hr. These data are the first to describe relative abundance of sea turtles observed from small vessels in this region. Detection of turtles <45 cm SSCL and data detail are greater than aerial surveys. The data serve to inform resource managers and researchers regarding these protected marine species.

Insights on Immune Function in Free-Ranging Green Sea Turtles (Chelonia mydas) with and without Fibropapillomatosis.

Chelonid alphaherpesviruses 5 and 6 (ChHV5 and ChHV6) are viruses that affect wild sea turtle populations. ChHV5 is associated with the neoplastic disease fibropapillomatosis (FP), which affects green turtles (Chelonia mydas) in panzootic proportions. ChHV6 infection is associated with lung-eye-trachea disease (LETD), which has only been observed in maricultured sea turtles, although antibodies to ChHV6 have been detected in free-ranging turtles. To better understand herpesvirus prevalence and host immunity in various green turtle foraging aggregations in Florida, USA, our objectives were to compare measures of innate and adaptive immune function in relation to (1) FP tumor presence and severity, and (2) ChHV5 and ChHV6 infection status. Free-ranging, juvenile green turtles (N = 45) were captured and examined for external FP tumors in Florida's Big Bend, Indian River Lagoon, and Lake Worth Lagoon. Blood samples were collected upon capture and analyzed for ChHV5 and ChHV6 DNA, antibodies to ChHV5 and ChHV6, in vitro lymphocyte proliferation using a T-cell mitogen (concanavalin A), and natural killer cell activity. Despite an overall high FP prevalence (56%), ChHV5 DNA was only observed in one individual, whereas 20% of turtles tested positive for antibodies to ChHV5. ChHV6 DNA was not observed in any animals and only one turtle tested positive for ChHV6 antibodies. T-cell proliferation was not significantly related to FP presence, tumor burden, or ChHV5 seroprevalence; however, lymphocyte proliferation in response to concanavalin A was decreased in turtles with severe FP (N = 3). Lastly, green turtles with FP (N = 9) had significantly lower natural killer cell activity compared to FP-free turtles (N = 5). These results increase our understanding of immune system effects related to FP and provide evidence that immunosuppression occurs after the onset of FP disease.

Venous blood gas and biochemical analysis of wild captured green turtles (Chelonia mydas) and Kemp's ridley turtles (Lepidochelys kempii) from the Gulf of Mexico.

Blood was collected from wild captured green and Kemp's ridley turtles off the west coast of Florida, USA. Blood gases and biochemical values were analyzed using a point of care (POC) device in the field. Analytes include pH, partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), oxygen saturation (sO2), lactate, sodium (Na), potassium (K), chloride (Cl), total carbon dioxide (TCO2), anion gap, ionized calcium, glucose, blood urea nitrogen (BUN), creatinine (Crea), hematocrit (Hct), and hemoglobin (Hb). These are novel data for wild healthy Kemp's ridley turtles, and results for green turtles were generally consistent with past studies of green turtles with exceptions primarily in blood gas values. Ninety percent of the green turtles had fibropapillomatosis (FP), but none of the blood analytes were correlated with disease severity. Only BUN was correlated with weight of green turtles, and there was no correlation between blood parameters and weight of Kemp's ridley turtles. This study provides data that are useful in understanding the physiologic status of sea turtles specific to this region, allowing for comparisons to other populations, life stages, and disease states.

Harmful algal and cyanobacterial toxins in foraging green turtles (Chelonia mydas) in Florida's Big Bend.

Numerous toxin-producing harmful algal (HAB) species occur in Florida's coastal waters. Exposure to these toxins has been shown to have sublethal effects in sea turtles. The objective of this study was to establish concentrations of 10 HAB toxins in plasma samples from green turtles (Chelonia mydas) foraging in Florida's Big Bend. Domoic acid, lyngbyatoxin-A, microcystins, nodularin, and okadaic acid were detected, demonstrating exposure to these HAB toxins, which are also a public health concern.

COMPARISON OF WHOLE BLOOD AND PLASMA GLUCOSE CONCENTRATIONS IN GREEN TURTLES ( CHELONIA MYDAS) DETERMINED USING A GLUCOMETER AND A DRY CHEMISTRY ANALYZER.

: We compared glucose concentrations in whole blood and plasma from green turtles ( Chelonia mydas) using a glucometer with plasma glucose analyzed by dry chemistry analyzer. Whole blood glucose (glucometer) and plasma glucose (dry chemistry) had the best agreement ( rs=0.85) and a small negative bias (-0.08 mmol/L).

Potential effects of brevetoxins and toxic elements on various health variables in Kemp's ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles after a red tide bloom event.

Natural biotoxins and anthropogenic toxicants pose a significant risk to sea turtle health. Documented effects of contaminants include potential disease progression and adverse impacts on development, immune function, and survival in these imperiled species. The shallow seagrass habitats of Florida's northwest coast (Big Bend) serve as an important developmental habitat for Kemp's ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles; however, few studies have been conducted in this area. Our objectives were (1) to evaluate plasma analytes (mass, minimum straight carapace length, body condition index [BCI], fibropapilloma tumor score, lysozyme, superoxide dismutase, reactive oxygen/nitrogen species, plasma protein electrophoresis, cholesterol, and total solids) in Kemp's ridleys and green turtles and their correlation to brevetoxins that were released from a red tide bloom event from July-October 2014 in the Gulf of Mexico near Florida's Big Bend, and (2) to analyze red blood cells in Kemp's ridleys and green turtles for toxic elements (arsenic, cadmium, lead, mercury, selenium, thallium) with correlation to the measured plasma analytes. Positive correlations were observed between brevetoxins and α2-globulins in Kemp's ridleys and α2- and γ-globulins in green turtles, indicating potential immunostimulation. Arsenic, cadmium, and lead positively correlated with superoxide dismutase in Kemp's ridleys, suggesting oxidative stress. Lead and mercury in green turtles negatively correlated with BCI, while mercury positively correlated with total tumor score of green turtles afflicted with fibropapillomatosis, suggesting a possible association with mercury and increased tumor growth. The total tumor score of green turtles positively correlated with total protein, total globulins, α2-globulins, and γ-globulins, further suggesting inflammation and immunomodulation as a result of fibropapillomatosis. Lastly, brevetoxin concentrations were positively related to tumor score, indicating potential tumor promotion by brevetoxin. These results signify that brevetoxins and toxic elements elicit various negative effects on sea turtle health, including immune function, oxidative stress, and possibly disease progression.