Dear MARMAM colleagues,

disturbances, organochlorine compounds may affect the health of a dolphin
population in a tropical estuary, Sepetiba Bay" recently published in Environmental Pollution. 

Abstract: 

Organochlorine compounds (OCs) are persistent organic pollutants linked to damaging the immune and endocrine
systems, leading to a greater susceptibility to infectious diseases at high concentrations. Sepetiba Bay, in the
Southeastern Brazilian coast, historically presents anthropogenic activities and environmental contamination
that could negatively impact resident populations. In this context, this study aimed to investigate the temporal
trends in the accumulation of organochlorine compounds over a 12-year database in the Guiana dolphins’
(Sotalia guianensis) resident population from Sepetiba Bay, including individuals collected before, during, and
after an unusual mortality event triggered by morbillivirus (n = 85). The influence of biological parameters was
also evaluated. The OCs concentrations in the blubber ranged from 0.98 to 739 μg/g of ΣPCB; 0.08–130 μg/g of
ΣDDT; <0.002–4.56 μg/g of mirex; <0.002–1.84 μg/g of ΣHCH and <0.001–0.16 μg/g of HCB in lipid weight.
Increased temporal trends were found for OCs in Guiana dolphins coinciding with periods of large events of
dredging in the region. In this way, our findings suggest that the constant high OCs concentrations throughout
the years in this Guiana dolphin population are a result of the constant environmental disturbance in the area,
such as dredging. These elevated OCs levels, e.g., ΣPCB concentrations found above the known thresholds, may
impair the response of the immune system during outbreak periods, which could lead the population to a progressive
decline.

The article can be found here <https://doi.org/10.1016/j.envpol.2024.123788> <https://www.sciencedirect.com/science/article/abs/pii/S0269749124005025?via%3Dihub>

Best regards,