DEEP.SEA RESEARCH PAU Il PERGAMON Deep-Sea Research 1149 (2002) 4983-5002 www.elsevier.com/locate/dsr2 Phytoplankton biomass,production and potential export in the North Water Bert Kleina,., Bernard LeBlanca, Zhi-Ping Meia, RachelBereta, Josée Michauda, C.-J. Mundyb, Ceci lie H. von QuillfeldtC, Marie-Ève Garneaud, Suzanne Royd, Yves Grattone, J. Kirk Cochranf, Simon Bélangerg, Pierre Laroucheg, J. Dean Pakulskih,l,Richard B. Rivkinh, Louis Legendrea,2 aGIROQ, Département de biologie, Universié Lava/, Qoebec, QC, Canada G1K 7P4 bCentrefor Earth Observation Science (CEOSJ, Department of Geography, University of Manitoba, Winnipeg, MB, Canada R3T lNl C Norwegian Polar Institute, Troms", Norway dISMER. Universir du Qlébec à Rimouski, Rimouski, QC, Canada G5L 3Al e INRS-ETE, Sainte-Foy, QC, Canada Gl V 4C7 rMarine Sciences Research Center, State University of New York, StonyBrook, NY 11794-5000, USA 1 Institut Maurice-Lamontagne, Minis~re desPêches et des Océans, Mont-Jo/i, QC, Canada G5H324 bOcean Sciences Center, Memor;a/University of NewFoundland, St. John's, NF, Canada A1C5S7 Received 24 October 2000; received in revised forrn 28 November 2001; accepted21 December 2001 Abstract The seasonal patterns of phytoplankton biomass and production were detennined in the North Water, located between Greenland and Ellesmere Island (Canadian Arctic), in August 1997,April-July 1998,and August-September 1999.The patterns differed among the four defined regions of this large polynya, i.e. North (> 77.S0N),East (> 7S0W), West « 7S0W), and South « 76°N). Phytoplankton biomass and production were low during April throughout the North Water. Biomass first increased in the East during April. From there, the biomass spread north- and westwards during May-June, when the bloom culminated (chlorophyll a concentrations up to 19.8 mg m-3). The large-sized (> 5 ~m) fraction dominated the biomass and production during the bloom. During July, August, and September, biomass and production decreased over the whole region, with the highest biomass, dominated by large cells, occurring in the North. The annual particulate and dissolved phytoplankton production were the highest ever reported for the high Arctic, reaching maximum values of 254 and 123gCm-2yr-l, respectively, in the East. Rates in the North and West were considerably lower than in the East (ca. two- and three-fold, respectively). Thef-ratios (i.e. ratio ofnew to total production), derived from the sile structure of phytoplankton, were high north of 76°N (O. 4--{). 7). Regionally. this indicated a high potential export of particulate organic carbon (Epoc) from the phytoplankton community to other trophic compartments and/or downwards in the East (155 g C m -2 yr-I), with lower values in the North and West (i.e. 77 and 42 g C m-2 yr-I, respectively). The seasonal and spatial patterns of EPOC were consistent with independent .Corresponding author. Tel.: + 1-418-656-7858; fax: + 1-418-656-2339. E-mail addresses: bcrt.klein@giroq.ulaval.ca (B. Klein). 1 Present address: Bigelow Laboratory for Ocean Sciences, 180 McKown Point Rd., West Boothbay Harbor, Maine 04575-0475, USA. 2Present address: Laboratoire d'Océanographie de Villefranche, BP 28, F06234 Villefranche-sur-Mer Cedex, France. 0967-0645/02/$ - see front matter @ 2002 Elsevier Science Ltd. Ali rights reserved. PlI: S 0 9 6 7 -064 5( 0 2 )00174-1