Влияние содержания органического углерода в донных отложениях Северного Каспия на численность и биомассу зообентоса

For the first time in the history of the researches on nutrition of benthic organisms in the Northern Caspian Sea, the assessment of statistical regularities between the content of organic matter in soils and benthos is made. Based on the ascertained statistical connections, there were defined 2 groups of benthic organisms: the biomass and number of the 1 st group are negatively correlated with the level of accumulation of organic carbon, while the biomass and number of the 2 nd group are positively dependent on the content of organic carbon. The concentration of organic carbon in bottom sediments of the Northern Caspian Sea for the period 1994-2011 changed from 0.01 to 2.82 %. Territorial distribution was heterogeneous. The greatest accumulation of organic carbon was fixed in sludgy soils. The destruction of organic matter in bottom sediments is caused by the abundance and biomass of infauna ( Chironomidae, Hypaniola kowalevskyi, Hediste diversicolor ). This group of organisms reduces a quantity of organic matter enhancing oxygen flow due to mechanical effect on the ground during the migration period. The coefficient of correlation between organic carbon and quantitative indicators of this group of organisms changed from -0.51 to -0.89. The most significant contact was fixed between organic carbon and the number of Chironomidae. The accumulation of organic carbon in the bottom sediments influences the abundance and the biomass of some representatives of nektobenthos ( Mysidae ), endobios ( Didacna protracta ), collectors ( Abra ovata ) and filter feeders ( Hypaniа angusticostata ). A positive correlation indicates an important role of organic matter in the nutrition of these hydrobionts. The coefficient of correlation between organic carbon and the number and biomass of the above-listed organisms changed from +0.67 to +0.93. The highest values of the correlation coefficient are fixed between the organic carbon content and the number of Paramysis ullskyi ( Mysidae ).