Shift towards the dominance of boreal species in the Arctic: inter-annual and spatial zooplankton variability in the West Spitsbergen Current

Abstract

We studied summer mesozooplankton composition between 2001 and 2009, in the epipelagic zone of the West Spitsbergen Current (WSC) and adjacent areas, which constitute a transition zone between warmer Atlantic and cold Arctic waters. According to hydrography and species composition, this region could be divided into 4 main areas: western and eastern branches of the WSC, the Greenland Sea together with Fram Strait, and the shelf areas of Spitsbergen and the Barents Sea. The most abundant species was Oithona similis and the most important, in terms of biomass, was Calanus finmarchicus; both species were found at all stations. The novel spatial analysis method of principal coordinates of neighbour matrices (PCNM) and the following variation partitioning were applied to disentangle the contributions of environmental variables and spatial differences in explaining mesozooplankton community variation. In spite of the large geographic area covered, environmental factors used in redundancy analysis (RDA) explained 30.6% of zooplankton variability, while the spatial distribution of sampling stations was responsible for 27.2%, and 12.5% was a common share of both predictors, coming from their correlations. We observed a smooth change from dominance of ubiquitous and boreo-Arctic taxa such as O. similis and Triconia sp. in the beginning of the study period towards stronger dominance of boreal taxa such as C. finmarchicus, which was the most abundant species in 2009.

Seasonal Variation in Transport of Zooplankton Into the Arctic Basin Through the Atlantic Gateway, Fram Strait

“…Time series of 9-14 years from the WSC indicate that with a warming AW we can expect higher abundances of the Atlanticboreal species C. finmarchicus and Oithona similis (Weydman et al, 2014;Gluchowska et al, 2017a). However, based on optical data with high spatial resolution the generally patchy distribution of zooplankton has been confirmed for a region of the AW inflow in the Fram Strait (Trudnowska et al, 2016).…”

Responses in Arctic marine carbon cycle processes: conceptual scenarios and implications for ecosystem function

“…These positive feedbacks may be significant for the global climate system (Symon et al 2005;Rhein et al 2013) but may also have large implications for the functioning of Arctic marine ecosystems and subsequent consequences for the marine carbon cycle in these polar waters. Indeed, ecosystem structure changes have already been observed in the Arctic (e.g., Wassmann & Reigstad 2011;Grebmeier 2012;Weydmann et al 2014).…”

First records of Lacydonia eliasoni Hartmann-Schröder, 1996 (Polychaeta: Phyllodocida) in the European Arctic

“…As is the influence of this increase on the composition, productivity and diversity of functional traits of both planktonic and benthic communities (Drinkwater 2006;Weydmann et al 2014;Meyer et al 2015). Organisms with pelagic life stages have better dispersal potential and should be the first to react to changing environments with range expansions (e.g.…”