Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s
Abstract The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), wh...
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2005
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Online Access: | http://dx.doi.org/10.1016/j.icesjms.2005.04.024 http://academic.oup.com/icesjms/article-pdf/62/7/1205/29124625/62-7-1205.pdf |
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croxfordunivpr:10.1016/j.icesjms.2005.04.024 2024-10-06T13:47:48+00:00 Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s Alheit, J. Möllmann, C. Dutz, J. Kornilovs, G. Loewe, P. Mohrholz, V. Wasmund, N. 2005 http://dx.doi.org/10.1016/j.icesjms.2005.04.024 http://academic.oup.com/icesjms/article-pdf/62/7/1205/29124625/62-7-1205.pdf en eng Oxford University Press (OUP) ICES Journal of Marine Science volume 62, issue 7, page 1205-1215 ISSN 1095-9289 1054-3139 journal-article 2005 croxfordunivpr https://doi.org/10.1016/j.icesjms.2005.04.024 2024-09-17T04:32:23Z Abstract The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces. After 1987, phytoplankton biomass in both systems increased and the growing season was extended. The composition of phyto- and zooplankton communities in both seas changed conspicuously, e.g. dinoflagellate abundance increased and diatom abundance decreased in the CBS. Key copepod species that are essential in fish diets experienced pronounced changes in biomass. Abundance of Calanus finmarchicus (NS) and Pseudocalanus sp. (CBS) fell to low levels, whereas C. helgolandicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes in biomass of different copepod species had dramatic consequences on biomass, fisheries, and landings of key fish species: North Sea cod declined, cod in the CBS remained at low levels, and CBS sprat reached unprecedented high biomass levels resulting in high yields. The synchronous regime shifts in NS and CBS resulted in profound changes in both marine ecosystems. However, the reaction of fish populations to the bottom-up mechanisms caused by the same climatic shift was very different for the three fish stocks. Article in Journal/Newspaper Calanus finmarchicus North Atlantic North Atlantic oscillation Oxford University Press ICES Journal of Marine Science 62 7 1205 1215 |
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Open Polar |
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Oxford University Press |
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croxfordunivpr |
language |
English |
description |
Abstract The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces. After 1987, phytoplankton biomass in both systems increased and the growing season was extended. The composition of phyto- and zooplankton communities in both seas changed conspicuously, e.g. dinoflagellate abundance increased and diatom abundance decreased in the CBS. Key copepod species that are essential in fish diets experienced pronounced changes in biomass. Abundance of Calanus finmarchicus (NS) and Pseudocalanus sp. (CBS) fell to low levels, whereas C. helgolandicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes in biomass of different copepod species had dramatic consequences on biomass, fisheries, and landings of key fish species: North Sea cod declined, cod in the CBS remained at low levels, and CBS sprat reached unprecedented high biomass levels resulting in high yields. The synchronous regime shifts in NS and CBS resulted in profound changes in both marine ecosystems. However, the reaction of fish populations to the bottom-up mechanisms caused by the same climatic shift was very different for the three fish stocks. |
format |
Article in Journal/Newspaper |
author |
Alheit, J. Möllmann, C. Dutz, J. Kornilovs, G. Loewe, P. Mohrholz, V. Wasmund, N. |
spellingShingle |
Alheit, J. Möllmann, C. Dutz, J. Kornilovs, G. Loewe, P. Mohrholz, V. Wasmund, N. Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s |
author_facet |
Alheit, J. Möllmann, C. Dutz, J. Kornilovs, G. Loewe, P. Mohrholz, V. Wasmund, N. |
author_sort |
Alheit, J. |
title |
Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s |
title_short |
Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s |
title_full |
Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s |
title_fullStr |
Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s |
title_full_unstemmed |
Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s |
title_sort |
synchronous ecological regime shifts in the central baltic and the north sea in the late 1980s |
publisher |
Oxford University Press (OUP) |
publishDate |
2005 |
url |
http://dx.doi.org/10.1016/j.icesjms.2005.04.024 http://academic.oup.com/icesjms/article-pdf/62/7/1205/29124625/62-7-1205.pdf |
genre |
Calanus finmarchicus North Atlantic North Atlantic oscillation |
genre_facet |
Calanus finmarchicus North Atlantic North Atlantic oscillation |
op_source |
ICES Journal of Marine Science volume 62, issue 7, page 1205-1215 ISSN 1095-9289 1054-3139 |
op_doi |
https://doi.org/10.1016/j.icesjms.2005.04.024 |
container_title |
ICES Journal of Marine Science |
container_volume |
62 |
container_issue |
7 |
container_start_page |
1205 |
op_container_end_page |
1215 |
_version_ |
1812175979655725056 |