Estimating explotiable biomass for sprat (Sprattus sprattus phalericus Risso, 1826) catched by midwater trawl in Middle Black Sea (Samsun-Yakakent, Ordu-Akçay)

In this study exploitable stock biomass of sprat (Sprattus sprattus phalericus (Risso, 1826)) distributed along Samsun shelf area (SSA) was estimaed for the period 2014 January – May. Swept Area method was used in the study. Exploitable sprat per unit area and stock biomass in the SSA in size 2.508,395 km2 was estimated for deeper and shallower waters than 40 meters which was accepted as midpoint. Accordingly, exploitable sprat per unit area was determined as; 40.018,76 ± 10.852,61 kg/km2 in shallower area than 40 meters, 27.758,77 ± 4.242,07 kg/km2 in deeper area than 40 meters and 33.602 ± 6.017,46 kg/km2 for SSA. The exploitable stock size of sprat was estimaed as 84.287 ± 15.094 tons in SSA. Average length values of sampled sprats were 7,08 ± 0,02 and it was determined that 7-7,4 cm is the densest size group in distribution of length-frequency. The other hand, length frequency distribution with respect to depth, densest size groups as follows; 7 – 7,4 cm for shallower waters than 40 meters, 6,5 – 6,9 cm for deeper waters than 40 meters.