TO THE ISSUE OF THE USE OF ASIAN PINK SALMON (oNCoRHYNCHUS GoRBUSCHA, WALBAUM) SCALE STRUCTURE FOR IDENTIFICATION IN MIXED MARINE CATCHES
Vladimir А. Savin, Roman А. Shaporev*, Viktor S. I, Аlexander V. Bugaev
Researcher; Researcher Engineer; Head of Dep., Dr. Sc. (Biology); Kamchatka Research Institute of Fisheries and Oceanography
Leading software engineer, The Government of the Kamchatka Territory
PINK SALMON, SCALE, SCLERITES, REGIONAL COMPLEX OF LOCAL STOCKS, STOCK DIFFERENTIATION, STOCK IDENTIFICATION, MIXED MARINE CATCHES
Results of analysis of Asian pink salmon scale structure are demonstrated and estimation of the possible use of the structure as a differentiation marker in identification of mixed marine catches is made. Five regional complexes of stocks are figured out on the base of the analysis of baselines collected in 2010, each having specific formation of sclerites in the first annual zone on the scale: 1) of Japan (Hokkaido); 2) of Sakhalin; 3) Northern Kuril populations (Paramushir); 4) of West Kamchatka; 5) of East Kamchatka. A complex of simulation tests is applied and results demonstrate quite high regional resolution ability of the model suggested (93,6% averaged). Identification is made for the samples from the drift net catches collected by RMV “Kadet-701” and SRTM-K “Leonid Khodyko” in June–August of 2010, and it is demonstrated that the results illustrate general commercial conjuncture in the year of the research. Correlations between coefficients of variation of the regional boot-stripe values and the number of sclerites used (in the zone of the 1st year) were analyzed. It is demonstrated that the model is stable when the number of the sclerites used is 11–15, and that allows regional identification of Asian juvenile pink salmon in marine catches possible.
THE DISTRIBUTION OF THE CATCHES AND THE SIZE COMPOSITION OF SAFFRON COD (ELEGINUS GRACILIS (TIL.)) IN THE DANISH SEINE CATCHES ON THE WEST COAST OF KAMCHATKA IN 1995–2015
Olga V. Novikova
Senior Scientist, Ph. D.; Kamchatka Research Institute of Fishery and Oceanography
SAFFRON COD, TAC REAlIzATION, SIzE COMPOSITION, DISTRIBUTION
More or less intense fishing of saffron cod operates on West Kamchatka year round and exploits spawning or feeding aggregations of this species. In 1995–2015 the total allowed catch of saffron cod fluctuated in the range 4.382–32.570 thousand tons, what is 13.341 thousand tons averaged. The body length of the fish in the commercial catches varies from 15 to 52 cm, averaged 34.0 cm. The major fishery pressure spreads over the fish with the body length from 30 to 40 cm, making up 70–80% in the total catch. The difference in the extremum and mean values of saffron cod between years in different commercial seasons is not great. It is demonstrated, that in winter, when the depth of fishing increases, the average body length of the fish has the trend to decrease. On the shelf of West Kamchatka saffron cod, no matter the level of biomass, demonstrates stable commercial densities in vicinity of three gyres of water masses in the south-western, central and northern parts of the shelf, where the major forage objects are concentrated.
CAPELIN (MALLOTUS VILLOSUS CATERVARIUS) FISHERY IN THE FAR EASTERN BASIN IN 2010–2016
Olga V. Novikova, Tatyana N. Naumova
Senior Scientist, Ph. D.; Researcher; Kamchatka Research Institute of Fisheries and Oceanography
PACIFIC CAPELIN, FISHERY, REALIZATION, FISHERY METHODS, SIZE COMPOSITION IN CATCHES
Fishing of Pacific capelin in the Far Eastern commercial fishery zones is provided by scoop-nets, pulling nets or fixed nets in spring-summer period, when capelin is spawning. In 2010–2016 the catch varied in the commercial subzones of the Far Eastern basin in the range 231.9–8399.5 t, being in the average 2348.6 t. The catch was maximal in the West-Kamchatkan subzone (42%). In 2016 the catches in the West-Kamchatkan, East-Sakhalin, West-Sakhalin and Petropavlovsk-Commander subzones visibly exceeded value recommended. The body length of the Sea of Okhotsk capelin in the catches was similar to the body length of Bering Sea capelin (18.0 cm in both cases), but the body weight was visibly higher (41.2 g vs. 14.6 g). Capelin individuals fromthe Sea of Japan (the West-Sakhalin commercial district) have the highest body length and weight: up to 21.0 cm and 59.0 g7
SOME DATA ABOUT LINEAR AND WEIGHT GROWTH OF CAPELIN MALLOTUS VILLOSUS CATERVARIUS DURING THE FIRST YEAR OF LIFE NEARSHORE ON WEST KAMCHATKA
Tatyana N. Naumova
Researcher, Kamchatka Research Institute of Fisheries and Oceanography
PRELARVAE, LARVAE, ALEVIN, UNDERYEARLING CAPELIN, LINEAR GROWTH, INCREMENTS, WEIGHT GROWTH, EASTERN PART OF THE SEA OF OKHOTSK
The linear growth and some aspects of the weight growth of capelin in the Eastern part of the Sea of Okhotsk during the first year of life were characterized for the first time. According to the averaged longterm data, the prelarva and later larva demonstrate linear growth from 6.6 to 20.4 mm in 4 early life months. Variations in the larval length composition have been demonstrated for these months, and one of determinants suggested is a very long spawning period and a very extensive spawning area where the time of emegrence is reasonably different. For the first year of life the capelin’s length can reach up to 80 mm averagely. The “age-body length” correlation is of S-shape and can be described satisfactory by logistic function. Monthly and daily capelin body length increments were calculated from formula. Some aspects of capelin’s alevin and underyearling distribution and feeding in winter have been analyzed. The growth for the first year of life can vary strongly from year to year, what indicates of unstable food supply for underyearlings in the Sea of Okhotsk. For a year since the emergence the individual weight of the Eastern part of the Sea of Okhotsk capelin has been increased from 0.12 to 2097 mg. Some aspects of larval capelin behavior on transit to exogenous feeding have been analyzed.
ON THE DEVELOPMENT OF THE TOTAL ALLOWABLE CATCH OF OKHOTSK HERRING CLUPEA PALLASII CUVIER ET VALENCIENNES, 1847 IN 2001–2016
Andrey M. Panfilov
Senior Scientist, Magadan Research Institute of Fisheries and Oceanography
OKHOTSK HERRING, FISHERY, CATCH, REALIZATION, THE SEA OF OKHOTSK, LAGOON
The dynamics of catch and the structure of the Okhotsk herring fishery in 2001–2016 are considered. The reasons for the reduction of catches during the spawning period are considered. In the current century, the annual total allowable herring catch is not fully developed. The herring fishery is divided into 3 periods: the wintering (pre-spawning), spawning and feeding. In the spawning and feeding periods, the catch does not correspond to the value of the allocated quotas. About half the size of the shortage is due to the state of the spawning herring fishery. The reasons for the decrease in the catch of spawning herring are analyzed. It is shown that the growth of catches is hindered by the uncertain status of the Okhotsk herring in the inland waters. An analysis is made of the state of the fishery of the spawning herring, and recommendations are given to increase the catches.
INFLUENCE OF SOME ENVIRONMENTAL FACTORS ON JUVENILE COHO SALMON ONCORHYNCHUS KISUTCH REARED AT THE VILYUISKY HATCHERY (KAMCHATKA) IN 2017
Tatyana V. Gavruseva, Elena V. Bochkova, Tatyana V. Ryazanova, Natalya V. Sergeenko, Elena A. Ustimenko
Head of the lab., Ph. D.; Senior Scientist; Leading Scientist, Ph. D.; Senior Scientist, Ph. D.; Senior Scientist, Ph. D.; Kamchatka Research Institute of Fisheries and Oceanography
PACIFIC SALMON, TOXICOSIS, AQUACULTURE
In this study, we analyzed the causes of increased mortality of juvenile coho salmon reared at the Vilyuisky hatchery in 2017. Based on the results of complex (virological, bacteriological, parasitological) studies of fish, it was established that the epizootic situation at the hatchery was satisfactory. The results of the histological and hematological studies showed structural abnormalities in the kidneys, liver and gills and degenerative changes in blood cells characteristic of toxicosis. Most likely, the increased mortality of fish arose against the backdrop of chronic toxicosis caused by poor-quality feeds and the periodic introduction of contaminated stream water in to the hatchery.