Respiration, Growth and Food Conversion Efficiency of Pinfish (Lagodon Rhomboides) Exposed to Sublethal Concentrations of Bleached Kraft Mill Effluent

Résumé du livre

Young pinfish (Lagodon rhomboides) (Sparidae) were exposed to 0·01%, 0·10% and 1·00% concentrations of neutralised bleached kraft mill effluent (BKME) for 28 days. Individual growth records were kept for fish fed 4·0% of their body weight per day. Fish exposed to 1·00% BKME demonstrated elevated gill ventilation rates and were characterised by reduced total lipid content, reduced condition factor, increased moisture and increased protein content when compared with controls. Control fish converted 44·6% of the ration to wet weight. Wet food conversions of pinfish exposed to 0·10% and 1·00% BKME were reduced by 47·8% and 73·5%. Conversion by fish in 1·00% BKME was reduced less in the second two weeks of the growth period, indicating possible acclimation to the pollutant. Conversions of dry weight and dietary protein were also reduced significantly in fish treated with 0·10% and 1·00% BKME. In 28 days, the total lipid content of control fish increased 298%. The increase was 140% in fish treated with 0·10% BKME and 67% in fish exposed to 1·00% BKME. Elevated maintenance metabolism was indicated. Growth in length was unaffected by BKME exposure. No respiratory, biochemical or food conversion differences were found between controls and fish exposed to 0·01% BKME. Differences were significant in concentrations of BKME less than 1·0% of the lethal concentration.