TP9 Ecotoxicology of Reptiles|
Tuesday, 15 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall
TP079 (RED-1117-837256) Effects of exposure to sodium perchlorate on histology and hormone levels of hatchling and mature male western fence lizards.
Start time: 8:00 AM
Redick-Harris, M1, Talent, L1, Janz, D2, 1 Oklahoma State University, Stillwater, OK, USA2 University of Saskatchewan, Saskatoon, SK, Canada
The purpose of our research was to determine the effects of in ovo exposure to perchlorate on thyroid hormone levels and the histology of thyroid and testicular tissue. Western fence lizard, , eggs were obtained from a laboratory population on the day of oviposition and incubated on perchlorate-spiked perlite at 28 °C. Hatchlings were divided into three groups. Two groups were euthanized, one was preserved for histological examination and the other was analyzed for thyroid hormones. The third group was reared to maturity to determine the effects of in ovo exposure on monthly growth in mass and snout-vent length and hormone levels at maturity. Perchlorate crossed the eggshell and accumulated in embryonic tissue at levels that exceeded exposure concentrations. Perchlorate can affect iodine uptake by the thyroid gland and interfere with the synthesis of thyroid hormones. Reduced thyroid hormone levels are known to affect the growth and development of many animals. In the present study, in ovo exposure to 0.195 mg perchlorate/g incubation substrate caused a reduction in hatchling whole body levels of thyroxine (T4) and triiodothyronine (T3). High doses of perchlorate also resulted in significant changes in thyroid gland colloid and follicular cells of hatchlings but no obvious effects on hatchling testicular histology was observed. In addition, in ovo perchlorate exposure did not significantly affect growth rate of lizards and no permanent effects were observed in mature lizards.
TP080 (RIC-1117-842119) Mercury and metal levels in snakes and tadpoles from the Mobile/Tensaw Delta, Mobile, Alabama.
Start time: 8:00 AM
Abalos, M1, Albrecht, J1, Rice, T1, 1 University of South Alabama, Department of Biological Sciences, Mobile, Alabama, USA
Mobile Bay, Mobile, AL, became a part of the country's National Estuary Program (NEP) in 1995. Included in the NEP study area is the Bay proper and the Mobile/Tensaw Delta. The Delta is one of the nation's largest river deltas and much of it remains in a natural state. The drainage basin of the Mobile/Tensaw Delta covers over 75% of the state of Alabama. Hence, a variety of human impacts over this large area could be funneling into the Delta. Of great concern to the citizens around Mobile Bay is the presence of mercury in food fish. However, it would be beneficial to measure levels of toxicants such as mercury, or heavy metals such as lead, in animals other than fish that are more abundant or occupy important ecological positions in the Delta. Surveys of the amphibians and reptiles in the Delta indicate that the bronze frog (Rana clamitans) and the Eastern ribbon snake (Thamnophis sauritus) are especially abundant and easily collected. Our goal was to measure mercury and heavy metals in these two species because they are not as commonly studied as higher profile species such as fish or birds. Ribbon snakes and tadpoles were collected from intact and clear-cut areas in the Delta. Whole animal tissue was processed for mercury and heavy metals. Both snake and tadpoles contained measurable amounts of mercury and heavy metals, but these levels did not appear high enough to be of concern. No appreciable differences in mercury or metal levels were observed between animals collected from clear-cut vs intact areas. Using these two species as bioindicators, the Mobile/Tensaw Delta appears to be relatively free of effects from mercury or heavy metals. However, other indicators of contamination in the Mobile/Tensaw Delta should be examined.
TP081 (JON-1117-837955) Acute toxicity, accumulation, and reproductive effects of HMX exposure in green anoles.
Start time: 8:00 AM
Jones, L1, Pan, X1, Cobb, G1, Anderson, T1, Lovern, M2, Smith, P1, McMurry, S1, 1 Texas Tech University, Lubbock, Texas, USA2 Oklahoma State University, Stillwater, Oklahoma, USA
Residues of explosives represent a significant environmental concern on many military installations. Over the years, much effort has been put into the study of the environmental fate of explosives and their exposure and effects in various organisms. High Melting Explosive (HMX) is currently one of the top four explosives used worldwide, and identified by DoD as a compound in need of study to assess exposure and effects endpoints in potential receptor organisms. Of particular need is information on the effects of explosives on reptile models. We selected green anoles (Anolis carolinensis) as our reptilian model species, as they are found in abundance throughout the southeastern U.S., from North Carolina to east Texas, and routinely cultured in the laboratory. Our study included three components; estimation of acute toxicity, determination of HMX transfer to eggs from contaminated soil, and maternal transfer of HMX to eggs and subsequent effects on hatching, survival, and growth of neonates. Acute toxicity (LD50) of HMX in adult male and female anoles was estimated using a standard up-down toxicity test and was determined to be >2000 mg/kg body weight. Accumulation of HMX into eggs incubating in contaminated soil was assessed at four concentration levels of HMX (0, 20, 200, and 2000 mg HMX per kg of soil). To determine maternal transfer of HMX into eggs, adult females were dosed via crickets injected with HMX to deliver four different doses (0, 20, 200, and 1000 mg/kg body weight). Results of all three components of the study are presented.
TP082 (CAR-1117-816024) Correlations between plasma polybrominated diphenyl ether (PBDE) concentrations and health parameters in loggerhead sea turtles.
Start time: 8:00 AM
Carlson, B1, Aleska, K2, Kucklick, J2, Arendt, M3, Segars, A3, Peden-Adams, M4, Keller, J2, 1 College of Charleston, Charleston, SC, USA2 National Institute of Standards and Technology, Charleston, SC, USA3 South Carolina Department of Natural Resources, Charleston, SC, USA4 Medical University of South Carolina, Charleston, SC, USA
Polybrominated diphenyl ethers (PBDEs) are chemicals used as flame retardants in textiles and electronics. They are not covalently bound to these substrates so they can leach into the environment. PBDEs have been quantified in humans and many marine wildlife species, but never in sea turtles. Additionally, the health effects of PBDEs in the threatened loggerhead sea turtle, Caretta caretta, are unknown. In 2003, this study sampled 29 juvenile loggerhead turtles captured within 8 miles of the coast of South Carolina, Georgia, and northeastern Florida. Plasma samples were extracted using liquid:liquid extraction and analyzed by gas chromatography with mass spectrometry to quantify 12 PBDEs, 83 polychlorinated biphenyl (PCB) congeners, and 20 pesticides. Health parameters such as plasma chemistry values, white blood cell counts, hematocrit, body condition, and immune functions, were also measured. The average total predominant PBDE (PBDE = sum of PBDE 47, 99, 100, 153, and 154) concentration was 109 ± 147 pg/g wet-mass basis (68.2± 75.1 ng/g lipid normalized basis). Spearman correlations were used to compare wet mass PBDE concentrations with health parameters, and no significant correlations were observed. However, lipid normalized concentrations were significantly correlated with several health indicators, but most of these indicators were also correlated with lipid content. This suggests that these correlations may be an artifact of the interrelated nature of these variables. Total predominant PCB (PCB = sum of PCB99, 118, 138, 153+132, 170, 180+193, 187, 196+203, 199) wet-mass concentrations were significantly negatively correlated with plasma lysozyme activity and positively correlated with urea nitrogen. These correlations corroborate a previous correlative study using sea turtles from North Carolina. Principle component analysis will be used to further assess which contaminant classes (PCBs, pesticides, perfluorinated compounds, and /or PBDEs) are responsible for the most variability in certain health parameters.
TP083 (MAT-1117-826982) The fence lizard (Sceloporus undulatus) as a reptilian model of endocrine disruption.
Start time: 8:00 AM
Wagner, D1, Matter, J1, 1 Juniata College, Huntingdon, PA, USA
To date, research on reptilian endocrine disruption has focused on semi-aquatic reptiles that exhibit temperature-dependent sex determination (TSD). The effects of in-ovo exposure to commercial pesticides were assessed in the northern fence lizard (Sceloporus undulatus hyacinthinus), to develop this species as an exclusively terrestrial, non-TSD reptilian model for assessing supposed estrogenic endocrine disruption. Eggs were dosed topically with low concentrations (1, 5, 10, 50, 100, and 500 ppb) of atrazine, alachlor, or trans-nonachlor dissolved in acetone as a vehicle. Eggs were treated with acetone alone as a negative control, while 17-estradiol (E2) was used as a positive control for estrogen-mediated effects. Hatchling lizards were housed in glass terraria and given access to crickets, water, and thermoregulatory opportunities. Growth parameters were monitored over an 18-week period. We evaluated growth as a function of change in body mass and snout-vent length (SVL). No significant growth effects were correlated with chemical exposures. Only eggs treated with E2 resulted in a significant sex ratio skew of hatchling young (100% female). Preliminary histological examination exhibited sexual and gonadal abnormalities in lizards treated with different compounds, including alteration of male secondary sex characteristics, mismatched internal and external sexual morphology, kidney hypertrophy, archinephric duct retention in females, and abnormal gonadal development. Work is currently underway to quantify histological effects on the gonads and kidneys.
TP084 (MAT-1117-829626) Effects of in-ovo organochlorine exposure on sex determination in fence lizards (Sceloporus undulatus).
Start time: 8:00 AM
Chemical contaminants have been shown to influence endocrine responses in species of wildlife living in polluted environments. Endocrine-disrupting compounds (EDCs) have been linked to abnormal gonadal morphology, reduced phallus size, and altered steroid hormone concentrations in alligators living at Lake Apopka, FL. Laboratory studies on alligators have shown gender-altering potential of EDCs contrary to expected sex ratios following incubation at male-producing temperatures. Critics of the EDC hypothesis claim that temperature-dependent sex determination (TSD) makes alligators especially susceptible to gonadal alteration by endocrine-active substances during embryonic development. In an effort to test this hypothesis, I have conducted exposure trials on fence lizard (Sceloporus undulatus) embryos. Sceloporus is known to possess sex chromosomes and provides an interesting comparison for other reptilian models examining the reproductive effects of EDCs. Female fence lizards oviposited eggs in the lab and these were randomly assigned to different treatment groups: 1) vehicle control (acetone), 2) 17-estradiol (E2), 3) o,p′-DDE (OP) and 4) p,p′-DDE (PP[both at 5, 50, and 100 ppb and 1 and 10 ppm]). In addition, binary combinations of the two DDE isomers (O+P) were used to examine potential interactions of these compounds. Young lizards were examined for phenotypic sex characteristics upon hatching. The typically estrogenic o,p′-DDE did not lead to significant ratio skews in Sceloporus undulatus hatchlings. In contrast, p,p′-DDE produced significant sex ratio skews (in favor of females), but resulted in mortality at doses of 1 and 10 ppm. Lizards were assessed for size at hatching (SVL and mass), and some individuals were examined for post-hatching growth potential to determine possible affects that organochlorine exposure may have on young. Overall, these studies indicate that Sceloporus is not different in its ability to experience developmental alteration due to EDC exposure than other reptilian systems, irrespective of their sex determining mechanism.
TP085 (ALA-1117-837587) Anthropogenic flame retardant compounds (PBDEs) measured in loggerhead eggs (Caretta caretta) of the US eastern coast.
Start time: 8:00 AM
Alava, Juan1, 3, Keller, Jennifer2, Kukclick, John2, Scott, Geoff1, 3, 1 Center for Coastal Environmental Health and Biomolecular Research (CCEHBR)/NOAA/NOS/NCCOS, Charleston, South Carolina, USA3 School of the Environment, University of South Carolina, Columbia, South Carolina, USA2 National Institute of Standards and Technology, Hollings Marine Laboratory, Charleston, South Carolina, USA
Polybrominated diphenyl ethers (PBDEs) are persistent organic contaminants broadly used as synthetic flame retardants since 1970. PBDEs have been detected in several species of marine mammals and seabirds, but not in marine turtles. The loggerhead sea turtle (Caretta caretta) has been recently utilized as a biological compartment in several ecotoxicological studies to conduct biomonitoring of pollutant concentrations (mercury, PCBs, pesticides, perfluorinated compounds) and to assess the potential effects of these contaminants on the health of this threatened species. PBDE congeners were measured in unhatched egg samples from 37 nests collected from beaches in North Carolina (NC) and both eastern and western Florida (FL) coasts in the summer of 2002. Yolk of eggs containing only early and middle stage embryos were pooled per nest. Twelve PBDEs congeners (BDE 17, 28, 47, 66, 71, 85, 99, 100, 138, 153, 154, 183) were measured by gas chromatography and mass spectrometry (GC/MS) in electron impact mode using a 60 m DB-5MS column. The NC nests had significantly higher concentrations of BDE (13.5 ng/g lipid) compared to eastern FL (2.23 ng/g lipid) and western FL nests (0.815 ng/g lipid; ANOVA p=0.001). This geographical variation is likely due to different foraging habitat during the seasonal migration and gradient of urbanization and industrialization along the eastern coast. Nesting females from NC are known to migrate to northern Atlantic Ocean waters to forage during the non-nesting season, while the females nesting further south migrate to more southern waters in the Gulf of Mexico, Florida coastal waters, and the Caribbean Sea. These spatial differences may be important because the northern subpopulation (e.g., NC), the one with higher PBDE concentrations, has been declining over the last three decades compared to the stable or increasing south FL subpopulation.
TP086 (GRO-1117-729313) An Evaluation of Organochlorine Pesticide Egg Treatment Methodologies in the American Alligator (Alligator mississippiensis).
Start time: 8:00 AM
Scarborough, J1, 2, Wiebe, J1, Rauschenberger, R2, Sepulveda, M2, Gross, T1, 2, 1 USGS-FISC-CARS, Gainesville, FL, USA2 University of Florida, Gainesville, FL, USA
The ability to establish a relationship between organochlorine pesticide (OC) exposure and subsequent reductions in egg and embryo qualities in repiltes are complicated by a variety of environmental and physiological parameters. In order to examine this potential relationship in more detail, egg injection and topical treatment methodologies were evaluated in our laboratory for the American alligator. Method 1: Eggs (n=56 eggs/treatment) were injected at the pole with a mixture of DDE, dieldrin, toxaphene, and chlordane in 10uL of triolien (vehicle) at three concentrations (high, intermediate and low). Three controls were utilized to validate the injection technique (control, sham control and vehicle control). Mortality rates among all injected eggs (approx. 70%) appear to be a result of injection technique as opposed to OC exposure. Method 2: Eggs (n=30 eggs/treatment) were topically administered with alternating single and multiple OC mixtures of DDE, dieldrin, toxaphene, and chlordane in sixteen treatment groups to examine the relationship between single and multiple OC exposure and subsequent increases in embryonic mortality. Though embryonic mortality was low (approx. 20% / treatment), OC absorption into the egg as determined by GC-MS was extremely poor (less than a 2-4% transfer). Topical application of OC on reptilian eggs has been discussed in several studies and porposed as a viable technique or screen for endocine disruptors, however, our data indicate that injection techniques in alliagtiors are not a viable method of exposure and that topical exposures do not result in significant exposure. These resulkts as well as our previous efforts with turtles do not support the use of either model as a method for screening endocine dsiruptors and/or effects. Most importantly, these efforts strongly indicate that egg exposures are not a likley or significant route of exposure to OC's in wild reptile populations.
TP087 (SUS-1117-741878) Filling Reptile Data Gaps using, the Western Fence Lizard: A Standard Toxicity Evaluation of 2, 4- dinitrotoluene.
Start time: 8:00 AM
Suski, J.1, Houpt, J.1, Bazar, M.1, Talent, L.2, 1 U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD, USA2 Oklahoma State University , Dept. of Zoology, Stillwater, OK, USA
2,4-dinitrotoluene, commonly known as 2,4-DNT, is an explosive frequently found in the soil of previously or currently operating military bases. Soil concentrations of 2,4-DNT were 0.458 to 237 micrograms per gram at one particular installation. Reptiles and specifically lizards are found on many military installations in both temperate and arid climates highlighting the importance of determining 2,4-DNT toxicity to these species. To date, there are few if any 2,4-DNT toxicity data for terrestrial, non-mammalian wildlife. Lizards were exposed to 2,4-DNT via oral gavage using a methylcellulose vehicle. First, a modified Median Lethal Dose (MLD) study was conducted using a stage-wise probit model, which allows for modification of the treatment dose mid-study based on results from previous stages. The MLD was 577.1 mg/kg for female and 380 mg/kg for male lizards. Continuing, a sub-acute experiment was initiated to further assess 2,4-DNT toxicity. Male lizards were dosed daily with 0, 6.25, 12.5, 25, 50, 100 or 200 mg/kg of 2,4-DNT for 14-days. Animals dosed with 100 and 200 mg/kg were euthanized prior to day 14 due to extreme lethargy and/or morbidity. Remaining animals were euthanized on day 14; at that time a gross necropsy was performed, organ weights were taken and blood was collected for clinical and hematological analysis. Surprisingly, analysis of animal weights, organ weights, food consumption, clinical chemistry and hematological parameters showed no significant effects of 2,4-DNT. Consequently, preliminary results suggest behavioral observations may be a sensitive indicator of toxicity. Following dosing some lizards displayed arched posture with increasing frequency in higher dose groups. In comparison, sub-acute mammal and avian studies reported significant differences in many parameters including body weight, food consumption and blood parameters following oral exposure to 2,4-DNT. These inter-species differences are corroborated by results from studies on other compounds as well. This study emphasizes the importance of reptile toxicity testing.
TP088 (UNR-1117-809829) Red-eared sliders (Trachemys scripta elegans) as long term indicators of environmental contamination.
Start time: 8:00 AM
Casey, E1, Bertsch, P1, Gaines, K2, Novak, J2, Stephens, W1, Unrine, J1, 1 Savannah River Ecology Laboratory, Aiken, South Carolina, US2 University of South Dakota, Vermillion, South Dakota, US
The timing and concentrations of contamination events are often unknown, which in part limits our knowledge of the extent of ecosystem exposure and related impacts. Evidence of the timing of historical contaminant exposure to organisms is particularly relevant in situations such as that at the Savannah River Site (Aiken, SC), where uranium and nickel (>40,000kg) were deposited from the mid 1950's through mid 1980's. A spillway breach in 1984 allowed for a release of this material into a relatively un-impacted ecosystem. Turtles are able to tolerate significant disturbance events, with contaminants being deposited in growth rings of their scutes and providing a chronological record of environmental contamination in a particular ecosystem. The purpose of this study was to test the utility of measuring contaminant deposition in turtle scutes as a historical record of environmental contamination events. Five hundred hatchling red-eared sliders (Trachemys scripta elegans) were gavaged with nickel citrate at concentrations of 25mg/L, 100mg/L, 400mg/L and a metal-free control during active periods on a bi-monthly basis since July 2003. All turtles were contained in experimental mesocosms with three replicates per treatment level. There was no apparent relationship between the concentration of nickel and mortality or growth rate (carapace length, plastron length, mass). Marginal and plastron scutes from control, 100mg/L, and 400mg/L individuals have been analyzed using a synchrotron x-ray fluorescence (SXRF) microprobe at the National Synchrotron Light Source (Brookhaven National Laboratory, Upton, NY). A gradient of nickel is apparent in the analyzed individuals in accordance with dosing concentration, and patterns of nickel and other elements (Cu, Zn, Ca) possibly in relation to dosing and feeding events within these scute sections were observed. The results of this study demonstrate the potential utility of red-eared sliders as a sentinel of historical patterns of environmental contamination in aquatic ecosystems.
TP089 (GRO-1117-727604) Thyroid function in hatchling American Alligators from contaminated sites in central Florida.
Start time: 8:00 AM
Wiebe, J1, 2, Scarborough, J2, Rauschenberger, R3, Smith, J1, Gross, T1, 2, 1 USGS-FISC-CARS, Gainesville, FL, USA2 University of Florida, Gainesville, FL, USA3 USFWS, Jacksonville, FL, USA
Several studies have demonstrated reproductive impairment for alligators exposed to a complex mixture of oprganochlorine pesticide residues (OC's). In addition to maternal mediated effects on egg quality and egg viability/hatchability, results have also documentd decreased offspring survivability and growth anomalies. Preliminary histological and hormonal evaluations of hatchling alligator thyroid activity suggest a potential relationship between organochlorine pesticide exposure and subsequent alterations in growth regulating tissues (i.e., thyroid). In order to evaluate this relationship further, clutches (n=10/site) were collected from lakes Apopka (High OC), Griffin (Intermediate OC), Orange (Control) and Emerelda Marsh (High OC). Hatchlings (n=15) were captive raised for a period of eight months. Morphometric measurements as well as monthly blood samples were collected. Plasma was utilized to monitor circulating free and total thyroxine (T4) concentrations (growth indicating hormones in reptilian models). In addition, thyroids were harvested from a subset (n=3 hatchlings / clutch) on a quarterly schedule in order to examine the potential relationship between growth morphometrics and subsequent alterations in thyroid function. Thyroid activity was quantitatively assessed utilizing morphometric analyses examining follicular diameter, area, epithelial height and colloid content. These data indicate altered thryoid function, and growth for alligator hatchlings in response to maternal and embryonic exposures to OC's.
TP090 (SWA-1117-652327) Organohalogen contaminant concentrations in blood of Kemp′s ridley sea turtles from the Gulf of Mexico.
Start time: 8:00 AM
Swarthout Jr, R1, 2, Keller, J1, Peden-Adams, M3, Fair, P4, Landry, A5, Kucklick, J1, 1 National Institute of Standards and Technology, Charleston, SC, USA2 College of Charleston, Charleston, SC, USA3 Medical University of South Carolina, Charleston, SC, USA4 National Oceanic and Atmospheric Administration, Charleston, SC, USA5 Texas A&M University, Galveston, TX, USA
The Kemp′s ridley sea turtle (Lepidochelys kempii) is the most critically endangered sea turtle species in the world. While the overt threats to the survival of the species, such as drowning in fishing gear and egg poaching, have been addressed by legislation and international treaties, more subtle threats such as environmental organohalogen contamination are not well understood. Existing data on organic contaminants in L. kempii come primarily from studies examining stranded or dead animals or animals caught through fisheries interactions. In the summers of 2001 and 2002, the National Oceanic and Atmospheric Administration in conjunction with Texas A & M University in Galveston captured and collected blood samples from live L. kempii along the northern coast of the Gulf of Mexico. Whole blood samples from 59 individual turtles were extracted using a novel microwave assisted extraction method and analyzed by large volume injection gas chromatography with mass spectrometric detection for polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and polybrominated diphenyl ethers (PBDEs). Concentrations of PCBs and OC pesticides were comparable but slightly higher than those that have been reported in L. kempii captured in the Atlantic Ocean. Due to the proximity to Mexico where dichloro-dibenzo-trichloro-ethane (DDT) was used more recently in controlling insect borne diseases, concentrations of 4,4′-DDT and total DDTs were expected to be higher than values reported for turtles captured in the Atlantic Ocean, but this was not the case. PBDEs were detectable in all blood sample extracts with BDE 47, BDE 99, BDE 100 and BDE 154 being the predominant congeners. These data contribute to the establishment of baseline contaminant concentrations in live populations of L. kempii and represent a step forward in determining the effects of organic contaminants on individual health and the viability of the population of this endangered species.
TP091 (FLE-1117-805552) Geckos as indicators of mining pollution.
Start time: 8:00 AM
Fletcher, D.1, Hopkins, W.1, Saldaña, T.2, Baionno, J.1, Arribas, C.2, Standora, M.1, Fernández-Delgado, C.2, 1 Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, USA2 University of Córdoba, Córdoba, Spain
Catastrophic collapse of a mine tailings dam released several million cubic meters of toxic mud and acidic water into the Guadiamar River valley in southern Spain. Remediation efforts removed most of the sludge from the floodplain, but contamination persists. Cleanup activities also produced clouds of aerosolized materials that further contaminated the surrounding landscape. We used the gecko Tarentola mauritanica, a common inhabitant of both rural and urban areas, to detect accumulation of trace elements in areas affected by the mine disaster. Their diverse habitat usage and carnivorous diet may make them excellent organisms to study uptake and effects of the mine pollution. Whole body accumulation of 21 elements was compared among seven locations that represent an expected gradient in mine contamination. Locations included a rural and an urban location not affected by the mine, two towns impacted by the mine disaster and three locations on the contaminated floodplain. Multivariate analyses of whole body element concentrations identified pollutants that increased across the expected contamination gradient, a trend particularly evident for As, Pb and Cd. Concentrations of these contaminants in the upper floodplain geckos were 52-, 9- and 5-times that of those from the rural reference site, respectively. Additionally examination of gecko gut contents revealed higher concentrations of contaminants in prey items of geckos from the mine affected areas. Comparison of element accumulation in tails with whole body concentrations also established the utility of tail clips as a nondestructive index of contaminant uptake. We conclude that the contaminated floodplain and urban areas affected by the disaster and mining activities remained sufficiently polluted for contaminants to enter the terrestrial food chain. In areas where abundant, geckos represent useful taxa to study the bioavailability of pollutants.
TP092 (MOS-1117-802128) Relative concentrations of POPs in the plasma of riverine turtles from the Tennessee River Gorge.
Start time: 8:00 AM
Moss, SM1, Wilson, TW1, Keller, JK2, Richards, SR, 1 University of Tennessee at Chattanooga, Chattanooga, Tennessee, USA2 National Institute of Standards and Technology, Hollings Marine Laboratory, Charleston, SC, USA
Persistent organic pollutants (POPs) are characterized by their persistence in the environment, ability to bioaccumulate, and potential toxicity to humans and wildlife. We report the concentrations of selected POPs in the plasma of two species of freshwater turtle, the common musk turtle (Sternotherus odoratus) and the Cumberland slider (Trachemys scripta). Five males and five female samples from each species were analyzed for 124 compounds (83 PCB congeners, 23 PBDE congeners, 6 DDT compounds, and 12 additional pesticides) using gas chromatography mass spectrometry in electron impact mode. The average PCB (sum of individual congeners) concentrations in S. odoratus were 12.7 ng/g and 13.0 ng/g, for males and females, respectively. For T. scripta, average PCB concentrations were 15.4 ng/g and 7.2 ng/g, for males and females, respectively. Average DDT concentrations for S. odoratus males and females were 1.5 ng/g and 6.7 ng/g, respectively. T. scripta showed average DDT concentrations of 0.545 ng/g for males and 0.597 ng/g for females, with 4, 4′-DDE as the predominant DDT compound. Average predominant PBDE concentrations (PBDE = sum of congeners PBDE 47, 99, 100, 153, 154 for S. odoratus were 1.37 ng/g for males, and 0.963 ng/g for females. For T. scripta, average PBDE concentrations were 0.875 ng/g for males and 0.506 ng/g for females. This study provides important baseline data on the riverine turtles of Tennessee, which can be used in risk assessment models and in the formation of conservation plans for the Tennessee River Gorge.