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Arctic Ocean outflow shelves in the changing Arctic: A review and perspectives
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-28)Over the past decade or so, international research efforts, many of which were part of the International Polar Year, have accrued our understanding of the Arctic outflow shelves. The Arctic outflow shelves, namely the East Greenland Shelf (EGS) and the Canadian Arctic Archipelago (CAA), serve as conduits through which Arctic sea ice and waters and their properties are exported to the North Atlantic. ... -
Asynchronous Accumulation of Organic Carbon and Nitrogen in the Atlantic Gateway to the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-15)Nitrogen (N) is the main limiting nutrient for biological production in the Arctic Ocean. While dissolved inorganic N (DIN) is well studied, the substantial pool of N bound in organic matter (OM) and its bioavailability in the system is rarely considered. Covering a full annual cycle, we here follow N and carbon (C) content in particulate (P) and dissolved (D) OM within the Atlantic water inflow to ... -
Bacterial response to permafrost derived organic matter input in an Arctic fjord
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-06)The warming of the Arctic causes increased riverine discharge, coastal erosion, and the thawing of permafrost. Together, this is leading to an increased wash out of terrestrial dissolved organic matter (tDOM) into the coastal Arctic ecosystems. This tDOM may be anticipated to affect both carbon and nutrient flow in the microbial food web and microbial community composition, but there are few ... -
Changes in marine prokaryote composition with season and depth over an Arctic polar year
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-13)As the global climate changes, the higher latitudes are seen to be warming significantly faster. It is likely that the Arctic biome will experience considerable shifts in ice melt season length, leading to changes in photoirradiance and in the freshwater inputs to the marine environment. The exchange of nutrients between Arctic surface and deep waters and their cycling throughout the water column ... -
How microbial food web interactions shape the arctic ocean bacterial community revealed by size fractionation experiments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-17)In the Arctic, seasonal changes are substantial, and as a result, the marine bacterial community composition and functions differ greatly between the dark winter and light-intensive summer. While light availability is, overall, the external driver of the seasonal changes, several internal biological interactions structure the bacterial community during shorter timescales. These include specific ... -
Importance of bacteria and protozooplankton for faecal pellet degradation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014)The degradation mechanisms of faecal pellets are still poorly understood, although they determine their contribution to vertical fluxes of carbon. The aim of this study was to attempt to understand the microbial (bacteria and protozooplankton) degradation of faecal pellets by measuring the faecal pellet carbon-specific degradation rate (FP-CSD) as an indicator of pellet degradation. ‘In situ’ and ... -
In the dark: a review of ecosystem processes during the Arctic polar night
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-28)Several recent lines of evidence indicate that the polar night is key to understanding Arctic marine ecosystems. First, the polar night is not a period void of biological activity even though primary production is close to zero, but is rather characterized by a number of processes and interactions yet to be fully understood, including unanticipated high levels of feeding and reproduction in a ... -
Influence of Phytoplankton Advection on the Productivity Along the Atlantic Water Inflow to the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-27)Northwards flowing Atlantic waters transport heat, nutrients, and organic carbon in the form of zooplankton into the eastern Greenland Sea and Fram Strait. Less is known of the contribution of phytoplankton advection in this current, the Atlantic Water Inflow (AWI) spanning from the North Atlantic to the Arctic Ocean. The <i>in situ</i> and advected primary production was estimated using the ... -
Microbial processes in a high-latitude fjord (Kongsfjorden, Svalbard) : II. Ciliates and dinoflagellates
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)The composition and ecological role of ciliates and dinoflagellates were investigated at one station in Kongsfjorden, Svalbard, during six consecutive field campaigns between March and December 2006. Total ciliate and dinoflagellate abundance mirrored the seasonal progression of phytoplankton, peaking with 5.8 9 104 cells l-1 in April at an average chlorophyll a concentration of 10 lg l-1. ... -
Planktonic food webs in the Arctic Ocean : structure and function in contrasting seasons and physical settings across Fram Strait
(Doctoral thesis; Doktorgradsavhandling, 2011-12-08)This thesis investigates the structure and function of planktonic food webs at two sites between Greenland and the Svalbard Archipelago, covering a coastal ecosystem influenced by Atlantic water masses (Kongsfjorden, 78º N) and a more oceanic system off the East Greenlandic shelf, influenced by the outflow of Arctic water and sea ice from the Arctic Ocean (northwest Fram Strait, 75 - 80º N). In ... -
Seasonal microbial processes in a high-latitude fjord (Kongsfjorden, Svalbard) : I. Heterotrophic bacteria, picoplankton and nanoflagellates
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)Temporal dynamics of the microbial food web in the Barents Sea and adjacent water masses in the European Arctic are to a large extent unknown. Seasonal variation in stocks and production rates of heterotrophic bacteria and phototrophic and heterotrophic picoplankton and nanoflagellates was investigated in the upper 50 m of the highlatitude Kongsfjorden, Svalbard, during six field campaigns between ... -
Synechococcus in the Atlantic Gateway to the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-05)Increasing temperatures, with pronounced effects at high latitudes, have raised questions about potential changes in species composition, as well as possible increased importance of small-celled phytoplankton in marine systems. In this study, we mapped out one of the smallest and globally most widespread primary producers, the picocyanobacterium Synechococcus, within the Atlantic inflow to ...
