IMMUNE PARAMETERS OF PLAICE, PLEURONECTES-PLATESSA, L ALONG A SEWAGE-SLUDGE GRADIENT IN THE FIRTH-OF-CLYDE, SCOTLAND

Plaice were caught at five stations varying in distance from the sewag e sludge dumping site at Garroch Head, in the Firth of Clyde, Scotland and a number of physical and immunological parameters monitored. Sign ificant intergroup differences were apparent in condition factor, hepa tosomatic index, serum protein concentration, serum lysozyme, serum im munoglobulin (Ig), liver vitamin E, kidney leucocyte respiratory burst activity and kidney leucocyte bactericidal activity. Of these paramet ers, the hepatosomatic index, serum lysozyme, serum Ig and kidney leuc ocyte bactericidal activity showed a negative correlation with distanc e from the dump site (that is, were highest at the dump site); serum p rotein and liver vitamin E showed a positive correlation. Factors foun d not to vary between the groups included the spleen index, serum anti protease activity and kidney leucocyte phagocytic activity. These find ings are discussed in relation to recent experimental data on the effe cts of sewage sludge exposure on the immune system of fish.