Variations in Year-Class Strength of Different Perch (Perca fluviatilis) Populations in the Baltic Sea with Special Reference to Temperature and Pollution
| Autor: | Richard Hudd, Hannu Lehtonen, Gunnar Thoresson, Paula Böhling, Erik Neuman, Peter Karås |
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| Rok vydání: | 1991 |
| Předmět: |
Abiotic component
Pollution Perch Biotic component biology Ecology media_common.quotation_subject Environmental factor Aquatic Science medicine.disease_cause biology.organism_classification Water level Baltic sea medicine Environmental science Water pollution Ecology Evolution Behavior and Systematics media_common |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 48:1181-1187 |
| ISSN: | 1205-7533 0706-652X |
| DOI: | 10.1139/f91-142 |
| Popis: | Variations in the year-class strength of perch (Perca fluviatilis) were analyzed among 23 populations in Baltic coastal areas distributed between 57 and 66°N using the age distribution in catches. In spite of large differences in abiotic and biotic factors, the variations in year-class strength were similar in 14 of these areas. The similarities could be attributed to large-scale weather variations influencing water temperature. Year-class strength was shown to be correlated with an index based on temperature and day length during the whole first year of life. In two of the nine deviating populations, perch nursery areas are situated in small nearshore freshwaters, where fluctuations in the water level may be more important for recruitment than temperature variations. The other deviating areas were exposed to environmental disturbances, i.e. acidification, oxygen deficits, pulp mill effluents, and thermal discharge, which obviously affected recruitment in a decisive way. |
| Databáze: | OpenAIRE |
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