Organochlorine compound accumulation in delphinids from Rio de Janeiro State, southeastern Brazilian coast Original Research Article

The present study investigated organochlorine compound levels (PCBs, DDTs and HCB) in blubber samples of six delphinid species from Rio de Janeiro State, southeastern Brazilian coast. The species analyzed inhabit the continental shelf (one killer whale, one false killer whale, two bottlenose dolphins, three rough-toothed dolphins, and four long-beaked common dolphins) and open ocean (four Fraserʹs dolphins). PCBs represented the greatest proportion of the sum of all measured organochlorines (from 0.60 to 257.2 μg g− 1 lw), followed by DDTs (from 0.15 to 125.6 μg g− 1 lw), and, at last, HCB (from < DL to 2.91 μg g− 1 lw). Higher concentrations were found in species that occupy the inner continental shelf (rough-toothed dolphin), as well as in cetaceans that are known to or are suspected to prey on other marine mammals (killer whale and false killer whale, respectively). The findings have shown that organochlorine levels in delphinids from southeastern Brazilian coast are comparable to those reported in cetaceans from highly industrialized regions of the Northern Hemisphere. Organochlorine accumulation patterns among delphinids from Rio de Janeiro State were related to habitat use.