The size and weight composition of by-catches of sturgeon fish by stationary seines in the near-shore area of the southeastern sector of the Sea of Azov

Abstract

The aim: the characteristics of the species, size and weight composition of sturgeon fish in the near-shore zone of the Sea of Azov.
Material: bycatch data from scientific monitoring of So-iuy mullet fisheries with stationary seines in the waters of the Temryuk Bay and in the Kerch Strait near the Chushka Spit in April 2024.
Results: sturgeon species were encountered in stationary seines in 100% of cases. The average catch per seine was 2–11 specimens per day. Starry sturgeon in Temryuk Bay accounted for more than 40% of the sturgeon bycatch, but it was not encountered in the Kerch Strait. Beluga Huso huso was noted in the Kerch Strait. The size range of Russian sturgeon varied from 30 cm to 133 cm; Starry sturgeon — from 102 to 118 cm. The average size of Russian sturgeon was 92.1 and 99.8 cm with an average weight of 9.2 and 6.4 kg, respectively, near the Chushka Spit and at the mouth of the Kuban. The average size of Starry sturgeon was 110.1 cm with an average weight of 6.7 kg. The length of the Beluga was 73 and 190 cm. The share of Russian sturgeon of commercial size (>90 cm) near Chushka Spit was 55%, in Temryuk Bay — 79%. 100% individuals of Starry sturgeon at the mouth of the Kuban were of commercially acceptable size (>80 cm).
Practical value: Observations of bycatch in stationary seines in the near-shore zone are the important source of data on the qualitative characteristics of sturgeon populations in the Sea of Azov.