FN Archimer Export Format PT J TI Calanus and environment in the eastern North Atlantic. 2. Role of the North Atlantic Oscillation on Calanus finmarchicus and C. helgolandicus BT AF FROMENTIN, Jean-Marc PLANQUE, Benjamin AS 1:1;2:1,2; FF 1:;2:; C1 Laboratoire d'oceanographie Biologique et d'Ecologie du Plancton Marin. URA2077, Station Zoologique. BP 28, F-06230 Villefranche-sur-Mer, France Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth PL1 2PB, United Kingdom C2 OBSERV OCEANOL VILLEFRANCHE, FRANCE HARDY FOUND OCEA SCI, UK IF 1.928 TC 0 UR https://archimer.ifremer.fr/doc/00033/14456/11758.pdf LA English DT Article AB The influence of the North Atlantic Oscillation (NAO) on 2 major zooplankton species ofthe eastern North Atlantic and the North Sea, Calanus finmarchicus and C. helgolandicus (Copepoda, Calanoida), was investigated. Our results confirm that from December to April, west wind stress (WWS) intensity and temperature are strongly related to the NAO. If these results were expected, more striking were the close relationships between NAO and Calanus species abundance. Fluctuations in abundance of C. finmarchicus mainly result from the combination of 2 factors, both driven by the NAO: WWS effects on spring primary production and temperature. The case of C. helgolandicus is more complicated,as the links between this species and the NAO result from the combination of several factors. Two of these factors, spatial heterogeneity of WWS strength over the area and temperature, are directly driven by the NAO. The third one, competition between the 2 Calanus species, is indirectly influenced by the NAO. Biogeographical boundaries of the 2 copepods are also modified by the NAO. Thus, in a comparable way to the El Nifio Southern Oscillation in the Pacific, the NAO impacts the pelagic ecosystem of the eastern Atlantic and the North Sea. PY 1996 PD APR SO Marine Ecology Progress Series SN 0171-8630 PU Inter-Research VL 134 BP 11 EP 118 ID 14456 ER EF