Archives / Volume 46
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.
УДК 597.541 (265.51DOI: 10.15853/2072-8212.2017.46.24-30Download the full article
The size and weight composition and the some data of the otolith shape analysis of underyearlings and two-year-old individuals of saffron cod Eleginus gracilis in the south-western part of the Bering Sea
It is demonstrated that the body length and weight of 0+ age saffron cod varied in the trawl survey catches in Karaginsky Gulf in October of 2013 in the ranges 5.3–16.8 cm and 0.5–30.5 g. The number of males and females was equal. Female and male average length and weight did not differ. The correlation between the length and weight of 0+ age saffron cod can be approximated through the y=0.0029x3,3077 power f unction cur ve. The weight growth rate in the underyearlings with the body length up to 10 cm and the body weight up to 5 mg is lower that in the bigger individuals. The otolith length in the underyearlings varied in the ranges 3.2–8.1 mm, the width – in the ranges 1.3–3.9 mm, and the weight – 3–32 mg. Tight positive correlation exists between the body length and weight of the fish and the otolith length, width and weight. The body length of 1+ age saffron cod in Karaginsky Gulf varies in the ranges 12.9–29.0 cm, and the weight – 13–190 g. The correlation between the body length and weight of 1+ age saffron cod is reflected in the function y=0.0025x3.3496. Females are bigger than males. The differences between their selective means, compared via Student’s test, are statistically significant. The difference in the growth rates of males and females of saffron cod in Karaginsky Gulf during their second year of life can occur due to mass gonad maturation in this age. The otolith length of two-year-old saffron cod can vary in the ranges 7.0–9.4 mm; the width – 2.7–7.4 mm, and the weight – 19–48 mg.
УДК 597-116:597.553.2 DOI: 10.15853/2072-8212.2017.46.31-41Download the full article
Non-commercial crustaceans of the northern part of the West Kamchatkan shelf in 2013–2014
As a result of processing 163 samples of benthos collected in the northern part of the West Kamchatkan shelf in 2013–2014, 186 species of non-commercial crustaceans belonging to 6 taxonomic groups were detected. The cr ustaceans were distr ibuted almost ever ywhere in the area examined, and their average biomass was 1.53±0.43 g/m2 and it was little bit higher in the northern part of area, and the population density was higher in the southern part. Different crustacean species dominated in the area examined on different grounds, often mixed.
УДК 574.583 DOI: 10.15853/2072-8212.2017.46.42-50Download the full article
Long term dynamics and modern state of zooplankton community in the Lake Dalneye
Transformations in the zooplankton community were figured out and analyzed for the long period from 1938 to 2016. It was found, that juvenile sockeye salmon abundance, being dependent on the level of spawning run, predetermins species composition, year-to-year changes in the population indexes and size composition of forage organisms. Different vulnerability of crustacean populations in terms of increasing pressure of resident and anadromous juvenile sockeye salmon stocks was due to different vertical distribution, fecundity and sizereproductive characteristics of the forage organisms.
УДК 556.51, 911.52 DOI: 10.15853/2072-8212.2017.46.51-65Download the full article
The correlation between morphometric characteristics, landscape drivers of flow generation and the characteristics of maximum and mean annual river flow in the Avacha River catchment (Kamchatka)
The study was to investigate the flow generation drivers and a landscape driver in particular in the basin of Avacha River (East Kamchatka).
In terms of poor meteorological information the actual instrument in the study was analysis of the hydrometeo monitoring data and using methods of remote sensing. First, we created a GIS which included published maps, field data Earth remote sensing (ERS) data and morphometric derivations for the Avacha basin area. We also made actual landscape map for the territory of the Avacha river basin. Our next step was estimation of the effects of morphometric characteristics and distribution of different landscapes on formation of mean and maximum flows on the base of updated hydrological data. In the third step we analyzed effects of the complex of runoff forming factors in the maximum flow during flood periods on the base of the formula of linear regression. It has been revealed, that the spatial distribution of certain landscapes has significant effect in the flow generation in western part of the basin, whereas the relief (morphometrical parameters) was the most contributing factor in the eastern part.
УДК 597.562 DOI: 10.15853/2072-8212.2017.46.66-70Download the full article
On the new record of larval saffron cod Eleginus gracilis (Til.)on West Kamchatka
Data of ichthyoplankton survey carried out on the shelf of West Kamchatka in June of 2016 were used in this article. Larval saffron cod was caught at the depth of 63 m. In June in the area of the capture (53º19´N and 155º37´E) the temperature of the water near the bottom was +1.7 ºC and on the surface – +6.8 ºC. Full length of larva was 9.7 mm. The larval body length was 9.6 mm, and the number of myomeres was 58–59.
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