Abundance and distribution of eggs and larvae of anchovy (Engraulis encrasicolus, Linnaeus, 1758) and horse mackerel (Trachurus mediterraneus, Steindachner, 1868) on the coasts of the eastern Black Sea

Abstract

Sampling for this survey was performed in 5 stations located in the bays of Sürmene and Rize in the eastern Black Sea between April and October 2006. During the sampling, the quantities and distributions of eggs and larvae of anchovies (Engraulis encrasicolus) and horse mackerel (Trachurus mediterraneus) were determined. For horizontal towing carried out from the surface (0–5 m), a plankton net of 50 cm in diameter and 500 µm mesh. The eggs of anchovy and horse mackerel sampled in plankton tows were found to be 438.33 ind./100 m3 and 5.71 ind./100 m3 for horizontal tows. During horizontal tows, the larvae of anchovy and horse mackerel were found to be 8.00 ind./100 m3 and 0.68 ind./100 m3, respectively. During the surveys, a total of 14,535 anchovy eggs, 147 horse mackerel eggs, 256 anchovy larvae, and 7 horse mackerel larvae were sampled. Mortality rates were calculated as 81.18% for anchovy and 37.41% for horse mackerel. According to our results, the ranges of spawning periods for anchovy and horse mackerel were determined as May–September and June–August, respectively.