Susan C. Gardner

Organochlorine contaminants in sea turtles from the Eastern Pacific.

We measured organochlorine residues in three species of sea turtles from the Baja California peninsula, Mexico. Seventeen of 21 organochlorine pesticides analyzed were detected, with heptachlor epoxide and gamma-hexachlorocyclohexane the most prevalent (14 (40%) and 11 (31%) of the 35 tissue samples, respectively). PCBs were detected in all but one of the 9 turtles studied, with congener 18 the most commonly detected (8 (23%) of the samples). The dioxin-like congeners 118 and 180 were detected in 4 (11%) and 3 (9%) of the samples, respectively. Percent contribution of congeners was negatively correlated to their octanol-water partition coefficients, with kidney and muscle containing more lower-chlorinated congeners than liver or adipose samples. Levels of organochlorines detected in the present study were low, potentially attributable to the feeding habits of the predominant species collected in this study (herbivorous) and/or the samples obtained in an unindustrialized region.

Hazards Associated with the Consumption of Sea Turtle Meat and Eggs: A Review for Health Care Workers and the General Public

Sea turtle products (e.g., meat, adipose tissue, organs, blood, eggs) are common food items for many communities worldwide, despite national regulations in some countries prohibiting such consumption. However, there may be hazards associated with this consumption due to the presence of bacteria, parasites, biotoxins, and environmental contaminants. Reported health effects of consuming sea turtles infected with zoonotic pathogens include diarrhea, vomiting, and extreme dehydration, which occasionally have resulted in hospitalization and death. Levels of heavy metals and organochlorine compounds measured in sea turtle edible tissues exceed international food safety standards and could result in toxic effects including neurotoxicity, kidney disease, liver cancer, and developmental effects in fetuses and children. The health data presented in this review provide information to health care providers and the public concerning the potential hazards associated with sea turtle consumption. Based on past mortality statistics from turtle poisonings, nursing mothers and children should be particularly discouraged from consuming all sea turtle products. We recommend that individuals choose seafood items lower in the food chain that may have a lower contaminant load. Dissemination of this information via a public health campaign may simultaneously improve public health and enhance sea turtle conservation by reducing human consumption of these threatened and endangered species.

Diet selection by immature green turtles ( Chelonia mydas ) at Bahía Magdalena foraging ground in the Pacific Coast of the Baja California Peninsula, México

In order to determine if eastern Pacific green turtles (Chelonia mydas) exhibit feeding preferences samples of recently ingested food items were compared to the food resources available in the marine environment where C. mydas congregates. Stomach samples were collected by conducting gastric lavage and, at the same time, vegetation transects were conducted during spring and winter. Green turtles in our study selectively consumed seaweeds, with Codium amplivesiculatum and Gracialaria textorii as preferred species. Differences in the consumption of species were found across the two mentioned seasons and were consistent with changes in the availability of different algae species in the environment. Based on these results, it is recommended that sea turtle conservation plans along the Baja California Peninsula include Pacific coastal mangrove channels with a high diversity of algae species as priority areas for protection.

Heavy metals dynamics in seaweeds and seagrasses in Bahía Magdalena, B.C.S., México

The process of metal bioaccumulation in marine food chains is poorly understood because very little data is available on metal concentration at different trophic levels and their temporal or spatial variation. Because of that, we were interested to (1) determine the concentration range of heavy metals in seaweed and seagrasses species in Magdalena Bay; (2) describe the spatial and temporal variation of heavy metal concentrations in the seaweeds and seagrasses. Seasonal collections were done at Estero Banderitas in November 2004, February, and April 2005 wherein we divided the estuary into three major areas (upper, middle, and lower), and within each area, two sites were selected. Our results showed that iron, copper, and magnesium were the most significant metals found in seagrasses, red, and green algae. We found significant more variation in temporal heavy metal concentrations in relation to the maximum abundance in the samples and spatial variation in relation to the studied taxa suggesting that hervibores have a differential intake of the metals. Also, our results suggest that heavy metals might be incorporated regularly in the diet of many herbivorous animals with severe consequences to their health. Management strategies for these species should consider monitoring the levels of metals.

Health Indices of the Green Turtle (Chelonia mydas) Along the Pacific Coast of Baja California Sur, Mexico. I. Blood Biochemistry Values

Abstract The green sea turtle (also known locally as black turtle; Chelonia mydas) is 1 of 5 species of sea turtles found along the coast of the state of Baja California Sur, Mexico, where several bays and lagoon systems provide an important growth and feeding habitat. We characterized blood biochemistry values of 67 green turtles captured at 2 mangrove estuaries along the Pacific coast of the Baja California Peninsula, Mexico, from 2005 to 2007. Blood samples were collected from live turtles for biochemical analysis of 18 parameters and analyzed by physical state (healthy, injured), size classes, season, and geographic location. Green turtles showed differences in the variability of the biochemical parameters between the 2 sites. In Punta Abreojos, injured sea turtles had lower calcium (28%), potassium (28%), and inorganic phosphorus (34.5%) levels and higher cholinesterase activity (16%) compared to healthy turtles. Juvenile turtles collected in Bahía Magdalena had higher glucose levels (34%) than subadults. Levels of triglycerides, total proteins, and albumin correlated positively with size. During the summer and during the years 2005 (Bahía Magdalena, BMA) and 2006 (Punta Abreojos, PAO), individuals had significantly higher concentrations of lipid (cholesterol and triglycerides), glucose, uric acid, and protein. Differences in the habitat, food availability, and environmental conditions between BMA and PAO were reflected in the variability of the biochemical parameters when compared by different factors, such as physical state, size, and seasonality. This is the first report of blood biochemical values of green sea turtles in the Pacific coast of Baja California, Mexico. All serum chemistry values of green sea turtles were within published reference ranges of healthy sea turtle population.

Vitellogenin in black turtle (Chelonia mydas agassizii): Purification, partial characterization, and validation of an enzyme‐linked immunosorbent assay for its detection

Black turtle plasmatic vitellogenin (VTG) was purified from 17beta-estradiol-induced males using ion-exchange chromatography. The isolated protein was identified as VTG by its glycolipoprotein nature and amino acid sequence homology with other vertebrate VTG. It was characterized as a 500-kDa dimer composed of two identical, 200- to 240-kDa monomers. Polyclonal antibodies raised against black turtle VTG showed high titer and specificity, as demonstrated by enzyme-linked immunosorbent assay and Western blot analysis, respectively. The range of the assay was estimated to be between 15 ng/ml and 2 microg/ml, and the inter- and intra-assay coefficients of variation were 9.4 and 7.3%, respectively. Black turtle antibody cross-reacted with VTG of two other sea turtle species, Caretta caretta (loggerhead) and Eretmochelys imbricata (hawksbill), extending the applicability of the assay as part of a sea turtle health assessment program.

Learedius learedi Price, 1934 (Trematoda: Spirorchiidae), in Black Turtle (Chelonia mydas agassizii) Hearts from Magdalena Bay, Baja California Sur, Mexico

Abstract Learedius learedi Price, 1934, is redescribed using specimens obtained from the hearts of 3 black turtles, Chelonia mydas agassizii, from Magdalena Bay, Baja California Sur, Mexico. The redescription is consistent with the original description but provides an unreported range of variation in testes shape and position and adds new information about the reproductive systems, such as the presence of a papilla in the pore of Laurers Canal and the presence of an external seminal vesicle instead of a preovarian seminal receptacle. Of 4 turtle hearts examined, only 1 was free of parasites (75% prevalence). In all, 128 parasites were found, a mean intensity of 43 worms per heart. This is the first record of the occurrence of L. learedi in C. m. agassizii in Mexico, expanding the known range of the parasite to the Baja California Peninsula.

Health Indices of the Green Turtle (Chelonia mydas) Along the Pacific Coast of Baja California Sur, Mexico. II. Body Condition Index

Abstract Body condition index is used as a measure for an individuals condition, usually with reference to its nutritional status and the energy reserves. Reproductive success, survival, and thus, population dynamics, depend on body condition of the organisms. In this study, the seasonal and annual body condition factor (a) and the relative body condition index (Krel) were estimated from the length–weight relationship of green turtles (Chelonia mydas) collected in 3 coastal lagoons of Baja California Sur during 2005–2007. Seasonal and annual differences in a, and differences between study sites and physical appearance (healthy or injured) of Krel were analyzed. Juveniles were the predominant age class (< 77 cm straight carapace length). Green turtles from Punta Abreojos (PAO) had a lower Krel than individuals of Laguna San Ignacio at a given size. In Bahía Magdalena (BMA) and PAO injured green turtles had a smaller Krel than turtles classified as healthy at a given size. Additionally, the increase in Krel per cm of straight carapace length of injured green turtles from PAO was lower than that of healthy ones. Body condition factor, a, varied between years in turtles from PAO, being highest during 2006. An increasing tendency in a, from winter to summer, was observed in PAO and BMA. The periods when green turtles had the highest body condition factor a (summer, 2005 BMA, 2006 PAO) coincided with periods of highest serum concentrations of glucose, proteins, lipids, calcium, and uric acid; nevertheless, the relative body condition index was not correlated with those parameters. The relative body condition index resulted in a simple and sensible method that provided an overall trend of the data under a number of stress conditions, detecting differences also between injured and healthy individuals. The body condition factor, in conjunction with blood biochemistry parameters, proved to be a useful tool as biomarkers of the apparent physical and nutritional status of the green sea turtles.

The Foragining Ecology of the Green Turtle in the Baja California Peninsula: Health Issues

Rafael Riosmena-Rodriguez1, Ana Luisa Talavera-Saenz1, Gustavo Hinojosa-Arango2, Monica Lara-Uc3 and Susan Gardner4 1Programa de Investigacion en Botanica Marina, Departamento de Biologia Marina, Universidad Autonoma de Baja California Sur, La Paz Baja California Sur, 2The School for Field Studies, Puerto de Acapulco s/n, Puerto San Carlos, Baja California Sur 3Depto. de Virologia, Facultad de Medicina Veterinaria y Zootecnia, UADY, Merida, Yucatan, 4Centro de Investigaciones Biologicas del Noroeste, La Paz Baja California Sur, Mexico