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The researches of the aquatic biological resources of Kamchatka and the North-West Part of the Pacific Ocean

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No 41 (2016)
5-16 223
Abstract
Specific traits of Pacific herring spawning near the mouth of the River Khairyuzova were figured out on the materials collected in May-June for the period 1998-2001 in the course of experimental fishing. It is demonstrated, that herring spawn in mentioned area every year and lay eggs on algae within the sublittoral zone. The body length of the spawning individuals in the trap net catches and bottom net catches varied in the range 16-34 cm. The age composition consisted of 1-15-year-old individuals. The minimal age of spawning herring was 3 years and body length - 20 cm. Majority of spawners had mature gonads at their 4 year of life, when the body length is 22 cm, what makes the Khairyuzova Pacific population different from the other two herring populations of adjacent areas of the Okhotsk Sea - Gizhigin-Kamchatkan and Okhotsk ones. Equations to describe correlations between the body length and weight and between the age and length or weight are provided. The average length in the age groups of herring near the mouth of the River Khairyuzova has found similar to the length in the Gizhigin and Okhotsk populations. The individual absolute fecundity estimated at IV and V stages of gonad maturation varied from 7.0 thous. eggs (4-year-old fish with the body length 21.5 cm) to 78.7 thous. eggs (13-year-old fish with the body length 30.5 cm). The average fecundity was 40.0 thous. eggs. Graphics and equations for the correlations between the fecundity and the age, the body length and weight of the fish are demonstrated.
17-42 218
Abstract
It is found, that about 99% of the total catch of sculpins is provided by Danish seining on the west coast of Kamchatka. The main part of the catch is from the Kamchatka-Kuril subzone. For the period 2001-2015 the catch varied from 3.2 (2008) to 11.6 (2005) and the average catch was 5.8 thousand tons. From 2001 to 2015 the stock of Cottidae was increasing. In recent years three geners within Cottidae family - Myoxocephalus, Gymnacanthys and Hemilepidotus, provided maximal contribution to the total biomass of Cottidae on the West Kamchatkan shelf: about 94% or 221 thousand tons. In 1986 - 2015 the highest biomass (116.7 thousand tons) and density (1329 kg/km 2) within the area of the research was provided by Myoxocephalus polyacanthocephalus. Analysis of the average length and the length composition of the fish for the periods 1970 - 1999 and 2000 - 2015 has revealed very few difference, what can serve indirect indication of a stable condition of sculpin populations.
43-50 338
Abstract
The paper presents data on the distribution of deep-sea king crab Paralomis multispina, red vermillion crab Paralomis verrilli and scarlet king crab Lithodes couesi, in the subdistrict 61.52 The Central part of the Sea of Okhotsk. The studied species had a low density of settlements in the designated area. Spawning process in P. verrilli from a trap catch was discovered here in early November. P. multispina was found to have a high degree of infestation by rhizocephalan Briarosaccus callosus (males 26.2%, females 20.1%), which was not observed in the other two species.
51-80 146
Abstract
The current strategy of management of Pacific salmon resource in Kamchatka has in its basis the idea, that a certain optimal part of parental salmon (stock) should enter rivers within extensive area in commercial fishery districts as an escapement. Meantime, if there were commercial interests of several countries, the control of fishery should be based on certain volums of the catch and the escapement into each particular stream. In this article we make the escapement to fit the maximal sustainable catch, for the most important streams within the Petropavlovsk-Commander fisheries subzone. In view of precautionary approach to evaluation and in regard to uncertainties the escapement is given in the form of interval. Two methodical approuches are demonstrated. The method of data stratification for the maximal, minimal and intermediate levels of reproduction, relevant to changes in environmental conditions, was used for the river Kamchatka, where series of observations is long. In accordance with this, the escapement estimates are given in the form of interval (average and extremes). As for the other rivers, where the series of observations over the escapement is shorter or fragmental and the fishing normally operates in the coastal zone (where origin of the fish returned hardly can be identified), the data pools were analyzed in geographic clusters of several rivers. As a rule the cluster mentioned consisted of one big river and several minor rivers around. The parameters of the corporate "stock-recruitment" model for all rivers of South-East Kamchatka (except Kamchatka River) used for estimation of the escapement, can be splitted into the parameters of models for particular clusters depending on the average longterm annual parental stock and progeny (recruitment) in every cluster. The article is the first in a series addressed to the theme, where similar work is planned to carry out for the rivers of North-East and West Kamchatka.
81-88 183
Abstract
Winter hydrological conditions in the Okhotsk Sea and the Western Kamchatka region of the Okhotsk Sea have been analyzed on the base of results of satellite monitoring of ice cover extent and sea surface temperature. Results of statistical processing are demonstrated. Five gradations of winter conditions have been revealed: extremely cold (outstandingly huge ice extent), cold (huge ice extent), normal, warm (narrow ice extent) and extremely warm (outstandingly narrow ice extent). The results obtained should be usefull for experts in oceanography and related disciplines, when developing or improving prognostic models.


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ISSN 2072-8212 (Print)
ISSN 2782-6236 (Online)