Carrot wastes and sewage sludge were used as supplementary feed for the common carp Cyprinus carpio. The growth rate of carp reared on 50% carrot waste was similar to that of carp fed with the control diets. Carp reared in sludge-supplemented diets showed adverse effects, further confirmed by changes of the protein and carbohydrate contents of carp during the experimental period.
The inferiority of sewage sludge as a supplementary feed for carp was further revealed by analysing the heavy metal contents in the diets, culture water and tissue of carp. A high level of various metals was found in sluge diets, causing a high uptake in the fish tissue, especially in those fish fed with the highest proportion (80%) of sludge.
According to the results of the present investigation carrot wastes have potential as supplementary feed for carp. Further research should be conducted in order to see to what extent the feeding of waste materials to fish can help in offsetting the cost of waste treatment, as well as providing a cheap form of fish food. Copyright © 1980 Published by Elsevier Ltd.
|Environmental Pollution Series A: Ecological and Biological
|Published - Sept 1980