КамчатНИРО
91
yearsKamchatka Research Institute of Fisheries and Oceanography
years
Journal / Archives
УДК 597.541 (265.51) DOI: 10.15853/2072-8212.2017.46.5-23Download the full article
The critical review of the Korf-Karagin herring underyearling size composition in the catches of bottom trawl surveys in the south-western part of the Bering Sea
According to the longterm data, collected during bottom trawl surveys in the gulfs of the south-western part of the Bering Sea, there are some patterns in the size composition dynamics of the Korf-Karagin herring underyearlings. The underyearlings appear in the catches of bottom trawl surveys first time in September. There are no any impressive changes in their catches until October. The catches in these months are similar in the range 2–1764 individuals per a hour-long trawling. Although the underyearlings were distributed up to the depth of 150 m in mentioned months, the maximal catch was observed over the isobaths up to 40 m. In November the catches of the underyearlings demonstrated multiple growth and were in the range 2–72 464 individuals per a hour-long trawling. In this month majority of the underyearlings comes to shelf from the shallow-water lagoons and bays, where the fish were feeding since their emergence. The maximal catch in November was observed over the horizon 61–70 m. In December the depth and the values of the underyearling catches were almost same as in November. The depth of the underyearling distribution on the shelf was maximal (170 m), but the maximal catch shifted closer to the shore (41–50 m).
During the whole observation period in the Karaginsky Gulf the catches of herring individuals with the body length <15 cm consisted of underyearlings. Older individuals in this size group could be seen in the catches in the examined part of the Bering Sea and in the Korfa Bay and Olyutorsky Gulf. The underyearling size composition varied extensively from year to year in all observation points. The part of big individuals (13–15 cm) increases “the more depth, the higher”, what can be due to presence of older individuals (>1-year-old) in the catches. In September the percent of the older fish increases in Olyutorsky Gulf in the east direction.