Preliminary study of the detection of antibodies to lymphocystis disease virus in flounder,Platichthys flesusL., exposed to contaminated harbour sludge

Flounder,Platichthys flesusL., were exposed to polluted harbour sludge, or to sludge wash-off in mesocosms for three years. Towards the end the study, a pilot experiment was initiated in which flounder antibodies against lymphocystis disease virus were measured in fish held in the mesocosms for 2·5 or 3 years. Although both the sub-sample sizes and number of fish with detectable antibody were small, it was found that between the two sampling periods there was a significant reduction in the number of antibody-positive fish in the mesocosm containing polluted harbour sludge, compared to fish in the mesocosm containing sludge wash-off, or a control mesocosm. The significance of that finding is discussed.