Long-term changes in phytoplankton, zooplankton and salmon related to climate

Beaugrand, G and Reid, PC 2003 Long-term changes in phytoplankton, zooplankton and salmon related to climate. Global Change Biology, 9 (6). 801-817. https://doi.org/10.1046/j.1365-2486.2003.00632.x

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Abstract/Summary

Recently, large-scale changes in the biogeography of calanoid copepod crustaceans have been detected in the northeastern North Atlantic Ocean and adjacent seas. Strong biogeographical shifts in all copepod assemblages were found with a northward extension of more than ° in latitude of warm-water species associated with a decrease in the number of colder-water species. These changes were attributed to regional increase in sea surface temperature. Here, we have extended these studies to examine long-term changes in phytoplankton, zooplankton and salmon in relation to hydro-meteorological forcing in the northeast Atlantic Ocean and adjacent seas. We found highly significant relationships between (1) long-term changes in all three trophic levels, (2) sea surface temperature in the northeastern Atlantic, (3) Northern Hemisphere temperature and (4) the North Atlantic Oscillation. The similarities detected between plankton, salmon, temperature and hydro-climatic parameters are also seen in their cyclical variability and in a stepwise shift that started after a pronounced increase in Northern Hemisphere Temperature anomalies at the end of the 1970s. All biological variables show a pronounced change which started after circa 1982 for euphausiids (decline), 1984 for the total abundance of small copepods (increase), 1986 for phytoplankton biomass (increase) and Calanus finmarchicus (decrease) and 1988 for salmon (decrease). This cascade of biological events led to an exceptional period, which is identified after 1986 to present and followed another shift in large-scale hydro-climatic variables and sea surface temperature. This regional temperature increase therefore appears to be an important parameter that is at present governing the dynamic equilibrium of northeast Atlantic pelagic ecosystems with possible consequences for biogeochemical processes and fisheries.

Item Type:	Publication - Article
Additional Keywords:	Zooplankton; Phytoplankton; Climatic changes; Marine environment; Long-term changes; Surface temperature; Temperature anomalies; Ecosystem disturbance; Pelagic environment; Geographical distribution; Sea surface temperature analysis; Copepods; North Atlantic Oscillation; Biogeography; Ecosystems; Crustaceans; Fisheries; Climatic effects on marine life; Ocean temperature effects on marine life; Salmon ecology; Northern Hemisphere weather; Calanus finmarchicus; Salmo salar; Calanoida; Euphausiidae; Copepoda; Salmonidae; Atlantic Ocean, North; AN, North Atlantic, North Atlantic Oscillation; Northern Hemisphere; ANE, North Atlantic
Subjects:
Divisions:	Sir Alister Hardy Foundation for Ocean Science > Other (SAHFOS) (expired)
Depositing User:	EPrints Services
Date made live:	20 Sep 2006
Last Modified:	25 Apr 2020 09:55
URI:	https://plymsea.ac.uk/id/eprint/1717

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