Anchovy population expansion in the North Sea
| Type | Article | ||||||||
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| Date | 2012 | ||||||||
| Language | English | ||||||||
| Author(s) | Petitgas Pierre1, Alheit Juergen2, Peck Myron A.3, Raab Kristina4, Irigoien Xabier5, Huret Martin 1, Van Der Kooij Jeroen6, Pohlmann Thomas7, Wagner Carola2, Zarraonaindia Iratxe8, Dickey-Collas Mark4 |
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| Affiliation(s) | 1 : IFREMER, F-44300 Nantes, France. 2 : Leibniz Inst Balt Sea Res Warnemunde, D-18119 Rostock, Germany. 3 : Univ Hamburg, Inst Hydrobiol & Fisheries Sci, D-22767 Hamburg, Germany. 4 : IMARES, Inst Marine Resources & Ecosyst Studies, NL-1970 AB Muiden, Netherlands. 5 : AZTI Tecnalia, Pasaia 20110, Gipuzkoa, Spain. 6 : CEFAS, Lowestoft NR33 0HT, Suffolk, England. 7 : Univ Hamburg, IFM, Inst Oceanog, D-22457 Hamburg, Germany. 8 : Univ Basque Country, Bilbao 48940, Spain. |
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| Source | Marine Ecology-progress Series (0171-8630) (Inter-research), 2012 , Vol. 444 , P. 1-13 | ||||||||
| DOI | 10.3354/meps09451 | ||||||||
| WOS© Times Cited | 83 | ||||||||
| Keyword(s) | Climate variability, Small pelagic fish, Regime shift, Temperature, Anchovy, North Sea | ||||||||
| Abstract | The abundance and spatial occupation of European anchovy Engraulis encrasicolus have increased in the North Sea since the mid-1990s. We use a cross-disciplinary approach combining genetics, transport modelling, survey time series analyses and physical oceanographic modelling to investigate 3 hypotheses on the reasons for this change. Evidence from connectivity studies suggests that the population of North Sea anchovy is separate from that in the Bay of Biscay. The recruitment pulses observed in survey data fit a life cycle which includes spawning in early summer and larval development in late summer. This also supports the concept of population expansion originating from local remnant population(s). In terms of growth physiology, suitable thermal windows have expanded, making conditions more favourable for life cycle closure and population persistence/productivity. In addition to the increased frequency of warm summers, which favour larvae and juvenile growth, the decrease in the number of severe winters is also likely to improve overwinter survival. Overall, the evidence supports the hypothesis that the increase in anchovy abundance originated from the improved productivity of existing populations. This increase was associated with an expansion in thermal habitats and is probably not due to a northward shift in the distribution of southern conspecifics. | ||||||||
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