Organochlorine pesticides in green sea turtles (Chelonia mydas) with and without fibropapillomatosis caught at three feeding areas off Brazil

Abstract

Many factors threaten the survival of marine turtles, such as incidental capture by fisheries, habitat degradation, pollution and diseases. One of the most important diseases is fibropapillomatosis (FP), characterized by the development of benign skin tumours. FP predominantly affects juvenile green sea turtles (Chelonia mydas) and involves a complex multifactorial aetiology. For several years, it has been noted that the prevalence of FP tends to be higher in marine environments under the influence of human activities, leading to the hypothesis that environmental pollutants play a role in the epidemiology of this disease. Organochlorine compounds (OCs) are persistent organic pollutants with immunosuppressive and carcinogenic effects in humans and wildlife. OC levels (α-BHC, β-BHC, α-endosulphan, β-endosulphan, endosulphan sulphate, pp′-DDD, op′-DDD, pp′-DDE, op′-DDE, heptachlor, dicofol and mirex) were quantified through gas chromatography with a micro-electron capture detector (GC-μECD) in liver and fat samples from 64 juvenile green sea turtles. Specimens with and without FP were analysed, after being caught at three feeding areas off the Brazilian coast: Ubatuba, Praia Grande and Vitória. OC levels were comparable to those observed in similar studies, and no consistent difference was observed between sea turtles with and without FP. This study helps to elucidate the contamination profile in sea turtles caught at feeding areas off Brazil and confirms that green sea turtles are exposed to OCs, which may play a negative role in the health of this species.

Monitoring green sea turtles in Brazilian feeding areas: relating body condition index to fibropapillomatosis prevalence

“…Rapid visual-assessment techniques of physical condition characterization are useful in field studies of wildlife health status (Thomson et al ., 2009); however, we observed that such techniques are adequate to differentiate between regular and poor, but not between good and regular body conditions, in which the employment of BCI techniques is indicated. Preliminary studies on green turtles captured in Brazilian feeding areas revealed the same results; that the subjective assessment is reliable for individuals in poor condition but is unclear for green turtles classified as regular and good (Sánchez-Sarmiento et al ., 2012). Another study carried out in Brazil demonstrated that the subjective body condition had a good relationship with BCI when examined by a single observer, avoiding inter-observer variation (Santos et al ., 2015).…”

The green turtle Chelonia mydas as a marine and coastal environmental sentinels: anthropogenic activities and diseases

“…Nevertheless, trace elements like lead, copper, and iron have been associated with altered blood patterns and oxidative stress parameters that possibly affect the dynamics of tumor pathogeny . Conversely, no consistent pattern of organic contaminant levels was observed to explain the difference between healthy and tumor-affected C. mydas in Brazil (SANCHEZ-SARMIENTO et al, 2017). The knowledge of those concentrations is still needed to obtain a better understanding of the cause-and-effect relationships of environmental contamination and C. mydas health parameters (KOMOROSKE et al, 2011).…”

Internal and Maternal Distribution of Persistent Organic Pollutants in Sea Turtle Tissues: A Meta-Analysis

“…Linear regressions (Supporting Information, S9), including 95% confidence intervals, are plotted to illustrate the general trend. Data from refs and – .…”