Klimaticheskaya izmenchivost i produktivnost tikhookeanskikh lososej Dalnego Vostoka Rossii

Abstract

An assessment of the effects of climate changes on Pacific salmon productivity in Russian Far East was made based on longterm data (1971-2015), including commercial fishery statistics and monitoring rows on 17 indices of teleconnection patterns. The assessment was made for three mass species - pink, chum and sockeye salmon. The values were obtained for three basin groups of stocks: PBS - the Pacific-Bering Sea group (East Kamchatka and Chukotka; SOS - the Southern Okhotsk Sea group (Sakhalin, Kuriles, the Amur River basin, Primorye); NOS - the Northern Okhotsk Sea group (West Kamchatka, continental coast of the Sea of Okhotsk). 6 Бугаев, Тепнин, Радченко The assessment of the interrelation and the selection of the indices of teleconnection patterns were carried using correlation and the principal component analysis. The results obtained allowed to figure out 10 indexes with the maximal time series (45 years), including ALPI, PNA, WP, PDO, NP, AO, N.HEMI+dSST, Ap, Sun Spot, LOD. Method of moving average was used in the calculations for making the rows of the average annual climate indexes. Averaging for particular species was carried out depending on duration of feeding at sea. In this connection the values of the moving average took into account the ranges of the variable values of indices from the year of juvenile migration to seawater and leaving the coast for the ocean waters (the age n.0) to the year of mass maturation (in the age 0.1 for pink salmon (averaging for two years - the ages 0.0 and 0.1), in the age n.3 for chum and sockeye salmon (averaging for 4 years - the ages n.0, n.1, n.2 and n.3)). In this way, the values obtained could demonstrate the effects of the climate factors on the Pacific salmon catches (production) taking into account the effects on salmon environment for the entire period at sea. Step-by-step multivariate regression analysiswas provided based on the indexes-indicators figured out and made figuring out the climate factors, which are the most affecting salmon prodiction in the basin groups of stocks of Pacific salmon in Russian Far East. All results obtained demonstrated authentic interrelations (p < 0.05-0.001) where the coefficients of the multiple regression from moderate (R = 0.36-0.74) to strong (R = 0.75-0.93). The highest level of the correlation “Pacific salmon production - the indices of teleconnection patterns” was revealed for chum and sockeye salmon, the species with a long period of feeding at sea. The indexes for pink slmon were visibly lower in the PBS and NOS groups. For the SOS group the coefficient of the multiple correlation was high. The results of the analysis made it possible to figure out the major active climate components as the N.HEMI+dSST (the index of the global temperature anomaly in the Earth Northern hemosphere), the PDO (the Pacific Decade Oscillation), the Ap (the index of the geomagnetic activities). The analysis of the zonal effects of the water temperature anomalies (aOST) in the areas of fall and winter feeding of Pacific salmon in the 1-st year of ocean life in the seas of Far East and Subarctic zone of Pacific Ocean has it indicated, that for the Okhotsk Sea groups (SOS and NOS) the maximal correlation the “aOST- catches” was in the fall in the central and southern Okhotsk Sea and also in the Pacific Ocean waters adjacent Kuriles: r = 0.4-0.7. The maximal correlations for the PBS group was in the west part of the Bering Sea: r = 0.3-0.5. The effects of the temperature factors on salmon productivity were visibly lower during winter feeding.