Zoning Of The North-western Part Of The Black Sea
ZONING OF THE NORTH-WESTERN PART OF THE BLACK SEA
BASED ON THE PARAMETRS OF MUSSELS GROWTH
A.Yu. Varigin
Odessa Branch Institute of biology of Southern Seas, National
Academy of Sciences of Ukraine
As is known, the growth of animal is an important integral parameter, which characterize a degree of suitablety of the environmental factors for development of this species in concrete location. The growth rate of mollusks depends first of all on depth, quality of fodder base, regime of temperature and salinity of water, density of settlements, degree of a wave action and some other factors. With the help of the analysis of character of growth of mussels it is possible to conduct ranking them locations on a degree of fitness both for natural development, and for simulated cultivation.
For the comparative analysis of mussel\’s growth samples from ten districts of the northwestern Black Sea [1.] were used. In these samples using sklerochronology method [2.] average lengths of shells for each age class were defined. Using the von Bertalanffy growth equation the asymptotic length of shell and growth coefficient “k” was calculated. For formalizing the obtained dates the procedure of their normalization was conducted, as the result of which the linear characteristics were converted to dimensionless indexes. The values of these indexes have formed the basis for build-up of a matrix of measures of intersection of parameters of mussels growth from different districts. Then the matrix of measures of likeness of these parameters was calculated. Using the theory of careless multitudes [3.] the comparative analysis was conducted.
As the result of the subsequent analysis, three major areas were selected, inside which between districts the greatest measure of likeness of growth parametrs was observed. So, the Central district and Zmeiny Island can be united in one area. The value of measure of likeness (S) for them was equal 79,5. Its lowest values are marked for Zmeiny island as contrasted to Dnestrovsky (S=13,8) and Tendrovsky districts (S=14,8).
Last districts can be united in other area. So, on Dnestrovsky district the growth of mussels was most similar to those on Sanzheika(S=76,9) and Odessa bay (S=74,2). The character of mussels growth on Sanzheika and Tendrovsky district was wery similar (S=83,3).
The third area was united by four districts, includes Shagansky bank and Filloforny field (S=82,3), and also Mezhvodnoe (S=74,9) and Tetis (S=69,2). The difference of this area from other also expresses in values of matrix of measures of likeness. So, the character of mussels growth on Dnestrovsky district is least similar to those on Shagansky bank (S=5,92), in Central district (S=19,1) and on Mezhvodnoe (S=13,9). So, the analysis of a matrix of measures of likeness has shown, that Central district and Zmeiny island includes in the first area, in second - Dnestrovsky, Tendrovsky districts, Sanzheika and Odessa bay, in third - Shagansky bank, Filloforny field, Mezvodnoe and Tetis.
Inside each of the major areas the boundaries of oscillations of the values of growth coefficient "k" were calculated. So, the limit of oscillations of the value “k” in I area was 0,29-0,30, in II area - 0,18-0,21, and in III area - 0,33-0,56. These datas confirm justification of the given zoning of the north-western part of the Black Sea.
References
1. Shurova N.M., Zolotarev V.N., Varigin A.Yu. 1991. Growth characteristics of the mussel Mytilus galloprovincialis in the north-western part of the Black Sea // Biologia morya, N4, P. 70-79(In Russian).
2. Zolotarev V.N. 1989. Marine bivalvia sklerochronology // Kiev, Nauk. dumka, 232 p. ( In Russian).
3. Andreev V.L. 1987. Analisys of ecologo-geografic datas using the theory of careless multitudes // L., Nauka, 154 p. (In Russian).
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