Potential adverse health effects of persistent organic pollutants on sea turtles: Evidences from a cross-sectional study on Cape Verde loggerhead sea turtles

Abstract

The Cape Verde nesting population of loggerhead sea turtles (Caretta caretta) is the third largest population of this species in the world. For conservation purposes, it is essential to determine how these reptiles respond to different types of anthropogenic contaminants. We evaluated the presence of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in the plasma of adult nesting loggerheads from Boa Vista Island, Cape Verde, and studied the effects of the contaminants on the health status of the turtles using hematological and biochemical parameters. All turtles had detectable levels of non-dioxin like PCBs, whereas dioxin-like congeners (DL-PCBs) were detected in only 30% of the turtles. Packed cell volume decreased with higher concentrations of PCBs, which suggests that PCB exposure could result in anemia in sea turtles. In addition, a negative association between some OCPs and white blood cells (WBC) and thrombocyte estimate was noted. The DDT-metabolite, p,p'-DDE was negatively correlated with the Na/K ratio and, additionally, a number of correlations between certain PAHs and electrolyte balances were found, which suggest that exposure to these environmental contaminants could affect the kidneys and salt glands in sea turtles. Additionally, several correlations were observed between these environmental pollutants (OCPs and PAHs) and enzyme activity (GGT, ALT, ALP and amylase) and serum protein levels, pointing to the possibility that these contaminants could induce adverse metabolic effects in sea turtles. Our results indicate that anthropogenic pollutants are present in the Cape Verde loggerhead turtle nesting population and could exert negative effects on several health parameters. Because of the importance of this loggerhead nesting population, protective regulations at national and international levels as well as international action are necessary for assuring the conservation of this population.

Clinicopathological findings in sea turtles assessed during the Deepwater Horizon oil spill response

“…Vargo et al (1986) exposed juvenile loggerheads to crude oil and studied both pathological and behavioral effects, some of which were later published by Lutcavage et al (1995). Much of the remaining literature relates to sporadic strandings of sea turtles oiled by unidentified sources or ingestion of floating tar balls, which are well-recognized threats to post-hatchling and pelagic juvenile sea turtles (Witherington 2002, Orós et al 2004, Camacho et al 2013. Based on these reports, the potential effects of petroleum exposure generally are believed to be multi-systemic and significant, but are incompletely defined.…”

The current state and future directions of marine turtle toxicology research

“…In vitro exposure drew correlations with organic contaminants Swarthout et al, 2010;Komoroske et al, 2011;Camacho et al, 2013a). One publication included both classes of contaminants (Komoroske et al, 2011).…”

“…For example, some of these studies (Camacho et al, 2013a(Camacho et al, , 2013b have been done on nesting turtles. Nesting females do not feed and instead rely on fat stores which can decrease body condition and influence biochemistry (Plot et al, 2013;Vieira et al, 2014).…”

Plasma Biochemistry values in wild female hawksbill turtle (Eretmochelys imbricata) during nesting in Mexican coast

“…Caliendo et al (2010) found an average of 1.4 mg/dL (± 404) of creatinine in the plasma of hawksbill turtles, and Ehsanpour et al (2015) by an average 0.23 mg/dL (± 0.03), normal values of creatinine as obtained in this study. Creatinine concentration determination was also the subject of studies by Camacho et al (2013), which presented a value lower than 0.1 mg/dL, and Innis et al (2008), which obtained the mean of 0.1 mg/dL (± 0.1), for the species L. kempii.…”

“…The (CAMACHO et al, 2013). According to Swimmer (2000), reptiles kept in captivity have higher levels of triglycerides, due to a high fat diet and insufficient exercise, or both.…”