Assessment of Food Supply of Small Pelagic Fish in the Black Sea Based on Their Lipid Content

Total lipids in anchovy and sprat were measured and interpreted as indicators of their nutritional condition and food supply for the period 2005 to 2010. High lipid content in anchovies suggested that they were able to found sufficient food and favorable environmental condition supporting their stock biomass on a certain level which was strongly limited by heavy fishing. Wide inter-annual fluctuations in anchovy landings could be caused by variability in yearly recruitment and due to shifts in the spatial distribution patterns of the exploited stock. Unlike anchovy, lipid reserves in sprat declined remarkably to the lowest levels recorded during the 50-year observations period. Such a significant worsening in sprat nutritional condition followed the evident warming of the Black Sea and coincided with a sharp decline in sprat catches off Crimea. Thus, the deterioration of food supply together with intensive fishing could have contributed to the reduction of that local sprat stock.