Abnormal Alligators and Organochlorine Pesticides in Lake Apopka, Florida

Woodward, Allan R.; Percival, H. Franklin; Rauschenberger, R. Heath; Gross, Timothy S.; Rice, Kenneth G.; Conrow, Roxanne

doi:10.1007/978-0-387-89432-4_5

Cited by 12 publications

(20 citation statements)

References 59 publications

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“…For example, environmental pollutants from a pesticide spill in Lake Apopka, Florida, were associated with a decline in juvenile alligator populations (7,8). This spill consisted primarily of dicofol contaminated with dichlorodiphenyltrichloroethane (DDT) and its metabolites (8), and significant concentrations of several organochlorine pesticides and metabolites have been detected in egg yolk and plasma obtained from alligators from Lake Apopka (9,10). Alligators from this lake exhibited morphological disorders such as poorly organized testes and small phalli, and decreased plasma T concentrations in juveniles (11)(12)(13).…”

mentioning

confidence: 99%

Identification and Characterization of the Androgen Receptor From the American Alligator,Alligator mississippiensis

et al. 2015

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Androgens are essential for the development, reproduction, and health throughout the life span of vertebrates, particularly during the initiation and maintenance of male sexual characteristics. Androgen signaling is mediated by the androgen receptor (AR), a member of the steroid nuclear receptor superfamily. Mounting evidence suggests that environmental factors, such as exogenous hormones or contaminants that mimic hormones, can disrupt endocrine signaling and function. The American alligator (Alligator mississippiensis), a unique model for ecological research in that it exhibits environment-dependent sex determination, is oviparous and long lived. Alligators from a contaminated environment exhibit low reproductive success and morphological disorders of the testis and phallus in neonates and juveniles, both associated with androgen signaling; thus, the alterations are hypothesized to be related to disrupted androgen signaling. However, this line of research has been limited because of a lack of information on the alligator AR gene. Here, we isolated A mississippiensis AR homologs (AmAR) and evaluated receptor-hormone/chemical interactions using a transactivation assay. We showed that AmAR responded to all natural androgens and their effects were inhibited by cotreatment with antiandrogens, such as flutamide, p,p'-dichlorodiphenyldichloroethylene, and vinclozolin. Intriguingly, we found a spliced form of the AR from alligator cDNA, which lacks seven amino acids within the ligand-binding domain that shows no response to androgens. Finally, we have initial data on a possible dominant-negative function of the spliced form of the AR against androgen-induced AmAR.

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confidence: 99%

Identification and Characterization of the Androgen Receptor From the American Alligator,Alligator mississippiensis

et al. 2015

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“…From a chemical pollutant perspective, it would seem as if females may have a protective mechanism, possibly depurating the chemicals via egg deposition. It is also possible that the larger females may be senescent as was investigated (but not confirmed) by Woodword et al (2011), implying that larger females have less opportunity for depuration via egg laying, but for the Nile crocodile, no firm data on age related reproduction seems to be available.…”

Section: Relationship To Mortalities and Possible Other Effectsmentioning

confidence: 97%

“…As for Wu et al (2006), we found that there was little inter-nest variation in pollutant concentrations in eggs, indicating that the eggs sampled represented the actual levels in clutches very well. Crocodilians ovulate all eggs simultaneously (Woodword et al, 2011;Lance, 1989), explaining why the pollutant concentrations in eggs from clutches are similar.…”

Section: Chlorinated Compoundsmentioning

confidence: 99%

“…There is much basis for inferring concern about reproductive performance, based mainly on information from the USA, Argentina, and Mexico (Guillette et al, 1994(Guillette et al, , 1995Milnes et al, 2005;Rauschenberger et al, 2007;Stoker et al, 2011;Woodword et al, 2011;Gonzalez-Jauregui et al, 2012). There is also concern about changes in behaviour (Clotfelter et al, 2004;Zala and Penn, 2004;Gonzalez-Jauregui et al, 2012) and gene-pollutant interactions (Moore et al, 2012).…”

Section: Relationship To Mortalities and Possible Other Effectsmentioning

confidence: 99%

“…The concentrations in Nile crocodile eggs could therefore be expected to be similar in the maternal body, and therefore informative of involvement or association. Woodword et al (2011) reported on the relationships between the deaths of 450 crocodiles in Florida and POPs (especially DDT) but did not mention pansteatitis as one of the symptoms. Although there is no evidence that any POP or similar chemicals can cause pansteatitis, neither has it been entirely excluded as a contributing factor.…”

Section: Introductionmentioning

confidence: 99%

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Chlorinated, brominated, and fluorinated organic pollutants in Nile crocodile eggs from the Kruger National Park, South Africa

Bouwman

Booyens

Govender

et al. 2014

Ecotoxicology and Environmental Safety

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a b s t r a c tRepeated annual episodes of Nile crocodile deaths in two isolated areas of the Kruger National Park prompted the investigation of possible organohalogen pollutant involvement. Crocodile eggs were collected close to one of the mortality sites (Gorge) as well as from a crocodile farm (CF) as reference. ∑DDT was significantly higher in Gorge (450 ng/g wm) than in CF eggs (85 ng/g wet mass). Percentage DDT of ∑DDT was significantly higher in CF (14 per cent) than in Gorge eggs (5 per cent). Mean ∑DDT was almost 70 times higher than mean ∑PCB in Gorge eggs. HCB, β-HCH, mirex, brominated flame retardants (BFRs), and perfluorinated compounds (PFCs) occurred at lower concentrations. We believe that the BFR and PFCs data represent the first published results for any crocodile egg. Thickening of the outer eggshell layer of Gorge eggs was significantly associated with higher concentrations of ∑DDT. Concentrations of ∑DDT and other pollutants were in the same range as eggs from elsewhere, where there were no mortalities. Concentrations of ∑DDT in eggs from healthy Australian crocodiles were of the same orders of magnitude as the current study, making it highly unlikely that the concentrations of pollutants measured in the present study would have caused or substantially contributed towards the mortalities observed. Concerns about reproduction and behaviour remain. As large predators, crocodilians are at the apex of the freshwater aquatic food web. More research is needed to guide measures to manage African freshwater systems so that it will also sustainably accommodate these large, long-lived animals.

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Effects of halogenated contaminants on reproductive development in wild mink (Neovison vison) from locations in Canada

Elliott

Kirk²,

Martin

et al. 2018

Ecotoxicology

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The concept of the Anthropocene, that humans are now re-engineering global ecosystems, is in part evidenced by the pervasive pollution by persistent organic pollutants (POPs). Certain POPs are hormone mimics and can disrupt endocrine and hence reproductive processes, shown mainly by laboratory studies with model species. There are, in contrast, fewer confirmations of such disruption from eco-epidemiological studies of wild mammals. Here we used the American mink (Neovison vison) as a sentinel species for such a study. Over the period 1998-2006, 161 mink carcasses were obtained from commercial trappers in the Canadian provinces of British Columbia and Ontario. Mink were aged, sexed, measured, and body condition assessed. Livers were analyzed either individually or pooled for organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and subsets for polybrominated diphenyl ethers (PBDEs). We primarily addressed whether contaminants affected male reproductive development by measuring baculum size and assessing the influences of age and body condition. We also considered the influence of spatial variation on relative exposure and size of baculum. Statistical models separated by age class revealed that significant relationships between baculum length or mass and juvenile mink were mostly positive, whereas for adults and first year mink they were mostly negative. A significant negative relationship for adult mink was determined between DDE and both baculum length and mass. For juvenile mink we found significant positive relationships between ∑PCBs, DDE and ∑PBDEs with baculum length. Our results provide some indication of negative effects of halogenated contaminants on male reproductive development in wild mink, and the most likely candidate chemical is the confirmed anti-androgenic compound, DDE, rather than PCBs or other compounds.

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Abnormal Alligators and Organochlorine Pesticides in Lake Apopka, Florida

Cited by 12 publications

References 59 publications

Identification and Characterization of the Androgen Receptor From the American Alligator,Alligator mississippiensis

Identification and Characterization of the Androgen Receptor From the American Alligator,Alligator mississippiensis

Chlorinated, brominated, and fluorinated organic pollutants in Nile crocodile eggs from the Kruger National Park, South Africa

Effects of halogenated contaminants on reproductive development in wild mink (Neovison vison) from locations in Canada

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