Gill damage as a determinant of residual oxygen concentration in the sealed jar test

fish to zinc and measur~ residual oxygen concentra­ tion after sealed jar test, secondly by putting healthy fish in sealed jars with known concentration of zinc and measuring residual oxygen concentration, and canparing both the above results with residual oxygen levels of healthy fish in clean water • .Additionally we have investigated the role of gill damage in deter­ mining the residual oxygen concentration by ligating gill arches, thus lllnit~ effective gill surface area, and carrying out sealed jar tests in clean water. In order to see if tissue oxygen consump­ tion may influence the residual oxygen concentration, the tests have been carried out at different tanperatures.