Eastern Baltic cod recruitment revisited—dynamics and impacting factors
| Autor: | Piotr Margonski, Karin Hüssy, Jan Dierking, Axel Temming, Friedrich W. Köster, Jens-Peter Hermann, Jonna Tomkiewicz, Viola Neumann, Bastian Huwer, Maris Plikshs, Daniel Oesterwind, Paul Kotterba, Andrei Makarchouk, Hans-Harald Hinrichsen, Margit Eero, Burkhard von Dewitz |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
Stock assessment Ecology Reproductive success biology 010604 marine biology & hydrobiology Fishing Sprat 04 agricultural and veterinary sciences Aquatic Science Oceanography biology.organism_classification 01 natural sciences Predation Fishery Herring 040102 fisheries 0401 agriculture forestry and fisheries Hydrography Ecology Evolution Behavior and Systematics Stock (geology) |
| Zdroj: | ICES Journal of Marine Science. 74:3-19 |
| ISSN: | 1095-9289 1054-3139 |
| DOI: | 10.1093/icesjms/fsw172 |
| Popis: | The Eastern Baltic cod abundance started rapidly to increase in the mid-2000s as evidenced by analytical stock assessments, due to increased recruitment and declining fishing mortality. Since 2014, the analytical stock assessment is not available, leaving the present stock status unclear and casting doubts about the magnitude of the recent increase in recruitment. Earlier studies identified main factors impacting on cod reproductive success to be related to the loss of two out of three spawning areas in the 1980s caused by lack of major Baltic inflows with a concurrent reduction in salinity and oxygen. Other important factors include prey availability for first-feeding larvae, egg predation by sprat and herring and cannibalism on juveniles, all in one way or the other related to the prevailing hydrographic conditions. These factors cannot explain increased reproductive success in the last decade, as the period was characterized by an absence of large-scale Baltic inflows since 2003 and persistent anoxic conditions in the bottom water of the deep Baltic basins. This questions the perception of the increased recruitment in later years and challenges our present understanding of cod recruitment dynamics in the Baltic Sea. In this contribution, we review evidence from the recent literature supplemented by information from latest research cruises to elucidate whether cod reproductive success indeed has increased during the last decade, and we suggest the key processes responsible for the recent dynamics in cod recruitment and outline directions for future research. |
| Databáze: | OpenAIRE |
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