Prevalence of skin ulceration in cod (Gadus morhua callarias L.) under anthropogenic contamination in the southeastern part of the Baltic Sea

Data on the occurrence of skin ulceration cases and concentrations of anthropogenic contaminants (PCBs; DDT; PAN; and heavy metals Hg, Pb, As, and Cd) in Baltic cod in the Russian exclusive economic zone (EEZ) of the southeastern part of the Baltic Sea are presented and an attempt is made to analyze the relationship between the prevalence of disease and contaminant concentrations. In 2005–2009 the prevalence of skin ulcers was 0.7%. The share of skin ulceration in fish was maximal in 3- and 6-year-old cod (1.0 and 1.1%, correspondingly) and in fish of the size group 39–45 cm (0.9%). Since 2007, a reduction of skin ulceration cases has been recorded in the Russian EEZ of the southern Baltic Sea. In 2005–2009, the concentration of contaminants in cod tissues did not exceed the permissible levels accepted in the Russian Federation. The relationship between the concentration of PCBs in skin and the prevalence of ulceration cases requires further studies.