Zooplankton structure in high latitude fjords with contrasting oceanography (Hornsund and Kongsfjorden, Spitsbergen)

Seasonal shifts in feeding patterns: Individual and population realized specialization in a high Arctic fish

“…Studies from the North American Arctic report a variety of ingested amphipod species with the predominance of set families or suborders depending on the region, essentially the Hyperiidea amphipod species T. libellula and Themisto abyssorum (Majewski et al, ), the Senticaudata amphipod, Apherusa glacialis (Walkusz, Majewski, & Reist, ), and Ampeliscidae amphipods, a family of the suborder Gammaridea (Cui et al, ). Our study highlights the ingestion of T. abyssorum in the Atlantic site of Smeerenburg in line with evidence supporting the presence of this amphipod in Atlantic domains (Ormańczyk, Głuchowska, Olszewska, & Kwasniewski, ).…”

“…Optimal diet theory (ODT) predicts that an increase in prey abundance and diversity should lead generalist predators to discriminate between preys and to specialize on higher value prey types (Sih & Christensen, ). Arctic fjords generally exhibit a diversity of potential prey such as T. libellula , T. abyssorum , euphausiids, and large calanoid copepods (Bandara et al, ; Cusa, ; Gluchowska et al, ; Ormańczyk et al, ), and the observed specialization on T. libellula could be the result of a seasonal behavioral specialization by a discriminating generalist. The predominance of T. libellula in the diet could also reflect a facility to catch this prey over other prey for a variety of reasons including handling ease, prey's color and visibility, aggregation and swimming behavior, and avoidance behavior.…”

Increased intrusion of warming Atlantic water leads to rapid expansion of temperate phytoplankton in the Arctic

“…In recent years, the influence of Atlantic waters along the WSC has also increased (Walczowski, Piechura, Goszczko, & Wieczorek, 2012), even extending into the eastern Eurasian Basin (atlantification sensu Polyakov et al, 2017). Many studies have reported increased importance of Atlantic species and atlantification of the marine food web west and north of Svalbard (Berge, Johnsen, Nilsen, Gulliksen, & Slagstad, 2005;Hegseth & Sundfjord, 2008;Orma nczyk, Głuchowska, Olszewska, & Kwasniewski, 2017;Wassmann et al, 2015;We z sławski, Buchholz, Głuchowska, & Weydmann, 2017). One in situ study in the summer of 2003 reported that E. huxleyi bloomed and dominated the phytoplankton assemblage in Atlantic waters that surfaced north of Svalbard (80-81°N, 30°E) with cell numbers up to 10 8 /m 3 (Hegseth & Sundfjord, 2008).…”

Pelagic Ecosystem Characteristics Across the Atlantic Water Boundary Current From Rijpfjorden, Svalbard, to the Arctic Ocean During Summer (2010–2014)

“…The boreal Calanus finmarchicus and Oithona similis INTRODUCTION Svalbard is located in a transition between boreal and Arctic biogeographic zones. This is most pronounced along the west coast of Svalbard, where the West Spitsbergen Current (WSC) transports Atlantic water (AW) northwards and where its influence is well documented on both protists (Piwosz et al, 2009(Piwosz et al, , 2014Hegseth et al, 2019) and zooplankton communities (Hop et al, 2006(Hop et al, , 2019Svensen et al, 2011;Vogedes et al, 2014;Soltwedel et al, 2016;Gluchowska et al, 2017b;Ormanczyk et al, 2017). North of Svalbard the Atlantic influence remains substantial as the AW Boundary Current turns eastwards, passing the Yermak Plateau, supplying AW, heat, nutrients and carbon along the upper continental slope en route to the Nansen Basin of the Arctic Ocean (Cokelet et al, 2008;Renner et al, 2018).…”