Chondrichthyans as biomonitor of Persistent Organic Pollutants in a nursery area off Argentina.

LB SCENNA; K. MIGLIORANZA; JM ROMAN; M. CHERICHETTI; F LO NOSTRO

Joao Pessoa

Congreso; Sharks Internaional Conference; 2018

Chondrichthyans are highly vulnerable to human impact, resulting in increased risk coastal species by its proximity to the terrestrial environment. Coastal marine areas can function as sinks for diverse anthropogenic pollutants, such as Persistent Organic Pollutants (POPs), which include organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Although these substances are banned in Argentina, they are highly persistent and lipophilic. Therefore, once released into the environment, POPs are bioconcentrated and biomagnified in the food web with the highest POPs levels in top predators. Fishes have been extensively used for monitoring studies because they concentrate pollutants in their tissues directly from the water and also through diet. In this sense, chondrichthyans are able to accumulate significant concentrations of POPs due to their relative longevity, moderate to large size, lipid-rich livers and high trophic position. An important nursery area for chondrichthyan species is located in coastal waters of Buenos Aires Province between 39º and 41º S (>endosulfans in C. callorynchus, indicating the historical use or a relative fresh input of DDT as impurity. However, in M. goodei the pattern was endosulfans>>DDTs, showing a recent use of endosulfans. The most abundant PCBs were tetra- and hexa- congeners, which could have stemmed from historical usage of Aroclor 1254 and 1260. Finally, the embryos of M. goodei, presented the same POPs pattern and similar values that pregnant females, indicating that maternal offloading may represent another important pathway of contaminant accumulation in viviparous species. These results suggest that chondrichthyans bioaccumulate high levels of POPs since early stages of development. In this way, continuous monitoring of the accumulation of POPs in chondrichthyans is necessary for adequate management and conservation of existing fisheries and aquatic resources.