SECTION 9 



ACCUMULATION AND METABOLISM OF PERSISTENT PESTICIDES 

 IN FRESHWATER FISH 



F.Ya. Komarovskiy and A.Ya. Malyarevskaya^ 



Long term utilization of persistent organochlorine pesticides, espe- 

 cially DDT, and BHC on a world wide basis has led to their distribution and 

 accumulation in a wide variety of media including soil, water, sediments, 

 and aquatic organisms. The accumulation of persistent pesticide residues in 

 organs of aquatic species and their tendency to be transformed in trophic 

 food chains are additional factors aggravating the danger of water pollution 

 by pesticides, both for regeneration of the biological resources of aquatic 

 ecosystems and for the health of man using fish for food. 



Studies of the last decade indicated the possibility of understanding 

 the fundamental principles of DDT distribution in the biosphere, including 

 the world ocean; its accumulation in the biota; the role of DDT in eco- 

 systems of different types; demonstrated the biological danger of DDT resi- 

 dues for animals and man; and established the mechanism of its metabolism 

 in abiotic media and in aquatic organisms. While our knowledge has in- 

 creased and information on the subsequent biological effects of wide-scale 

 DDT utilization has increased, a great number of unsolved problems requiring 

 further research remain. For example, comparatively little data are avail- 

 able on DDT accumulation in brain tissue of warm-blooded animals and fish, 

 even though the neurophilicity of the compound suggests that it should have 

 received the greatest attention. There are \/ery few studies available which 

 show that the development of clinical symptoms of intoxication in warm- 

 blooded animals correlates with an increase of DDT accumulation in brain 

 tissue (Hayden 1960). 



One of the most important principles of the biotic circulation of or- 

 ganochlorine pesticides, especially DDT, is their accumulation and trans- 

 formation in trophic chains, and their tendency to concentrate in the 

 highest links of these chains. This phenomenon is well demonstrated in 

 studies of terrestrial and marine ecosystems (Mayer-Bode 1966; 

 Andryuschchenko and Pishcholka 1975), but has received little attention in 

 freshwater ecosystems. 



1 Institute of Hydrobiology of the Ukrainian Academy of Sciences, 44, 

 Vladimirskaya St., Kiev, 252003, USSR. 



Ill 



