Long-term dynamics of biological indicators of navaga Eleginus nawaga (Walbaum, 1792) of the White Sea in relation to changes of the reservoir temperature regime
Journal Title: Вестник МГТУ - Year 2017, Vol 20, Issue 2
Abstract
Systematic studies of navagа of the White Sea were initiated in the late 1960-ies. Data sets on dimensional indicators, age composition of populations of navaga of the Onega, Dvina, Mezen Bays and Voronka of the White Sea have been accumulated during 45 years of observations. The aim of this work is to identify the causes of the interannual and long-term changes of biological population parameters of navaga. As investigated interannual changes reflecting fish growth, the length and mass of 2 and 3 years old specimens have been chosen. It has been proved that interannual fluctuations in length and weight may depend on the length of the feeding season, as well as the number of populations. Climate warming has resulted that over the past 45 years since the beginning of observations the water temperature in the White Sea in April on average has increased by one degree, and some years – even more. Due to lengthening of the feeding period the seasonal growth of navaga has increased, respectively the annual rates of its length and weight have increased as well. The increase in the growth rate of navaga in the Onega and Dvina Bays has led to its mass mature and joining the fishing (commercial) herd at the age of two years. In the Mezen Bay and Voronka the trend on the increase in annual average length and weight navaga of only younger age groups has kept. Growth rate of large size navaga has decreased due to the almost complete cessation of fishing and the increase of older fish number. The revealed regularities in the change of the navaga population parameters of the White Sea should be used for preparing the forecast data on the state of its reserves.
Authors and Affiliations
V. A. Stasenkov
Keywords
Related Articles
- EP ID EP225837
- DOI 10.21443/1560-9278-2017-20-2-370-380
- Views 96
- Downloads 0
Features of laser diodes' radiation in different temperature intervals
In the literature there is practically no information on the change in the characteristics of the emission spectrum of industrial semiconductor laser diodes in a wide range of temperatures, including cryogenic temperatur...
Estimation of morphometric and fish-breeding biological indicators of Siberian sturgeon (Acipenser baerii Brandt) from the Lena River population, rearing in the conditions of the Far North
Aquaculture is actively developing in the European North. This area is mainly based on using natural water bodies and the cultivation of cold-loving fish species. Sturgeon is a valuable and perspective object of warm-wat...
Industrial development of near-open pit reserves based on multivariate analysis and computer modelling of geotechnology objects
The conditions for potential production of deposit reserves are studied at the initial stage of its development as every deposit is a unique one. Mining conditions can change during production, therefore, it is necessary...
Evaluation of the functional activity of activated sludge from local waste water treatment plant in the Arctic region
The paper considers characteristics of the activated sludge in the local wastewater treatment plant (LWTP) and its ability to purify fully domestic sewage water in the Far North. Biochemical process of destruction of org...
The fractionation of 13С in the Тransbaikalia ecosystem
The analysis of isotopes of the main biogenic elements is carried out in determining the geographical origin of the sources of raw materials used for the manufacture of food products, as well as the authenticity of its o...