The influence of physical and chemical conditions on the forage invertebrates and fish of the Baltic Sea and the Gulf of Riga
The influence of salinity and the gas regime on the molluscs of the Baltic Sea - Macoma baltica, Cardium lamarcki, Mya arenaria, and Dreissena polymorpha - are considered. Of them M. arenaria is the least euryhaline species with the salinity range -0 - 4-5 psu. M. arenaria well tolerates low salinity and survives at 2.5-7.5 psu. But the species is poorly adapted to the rapid changes in the salinity of the environment. M. baltica is the most euryhaline and plastic species, its salinity range reaches from 4 to 25 psu. The salinity range of C. lamarcki little differs from that of M. baltica. D. polymorpha and M. baltica are comparatively resistant to the oxygen deficiency, C. lamarcki and M. arenaria do not tolerate the environment with the oxygen content below 1 ml/l. The influence of manganese on the molluscs of the Gulf of Riga - M. baltica, M. arenaria, D. polymorpha - was also analyzed. It was established that weak manganese solutions, 2-7.5 mg/l, stimulated the gas exchange in the molluscs. The concentration 17.5-20 mg/l provoked a sharp increase in their breathing intensity. The effect of still higher manganese concentrations upon the molluscs was negative - their gas exchange decreased and the number of perishing individuals increased. In the tissues of M. baltica dwelling in the bottom of the Gulf of Riga with traces of manganese, notable manganese accumulations were absent. However, in the tissues of the M. baltica in the sediments of the Gulf of Riga with a high manganese concentration and ferromanganese concretions, the manganese concentration in the tissues was considerable.
| Main Authors: | , |
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| Format: | Book/Monograph/Conference Proceedings biblioteca |
| Language: | Russian |
| Published: |
Baltijskij Nauchno-issledovatelskij Institut Rybnogo Khozyajstva; "Zvaigzne"
1970
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| Subjects: | Macoma baltica, Mya arenaria, Dreissena polymorpha, Invertebrates, ASFA_2015::E::Environmental factors, ASFA_2015::M::Marine invertebrates, ASFA_2015::S::Salinity effects, |
| Online Access: | http://hdl.handle.net/1834/43249 |
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