Stig Falk-Petersen

Stig Falk-Petersen
Akvaplan-niva · Research

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211
Publications
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Publications

Publications (211)
Article
The availability of food for the zooplanktivorous seabirds, such as an endemic High Arctic alcid, the little auk (Alle alle) is essential for its population status and in consequence for fertilizing nutrient-poor Svalbard tundra. Since the zooplankton composition and concentration vary over time and space on foraging grounds, it is challenging to m...
Article
Full-text available
Arctic sea ice contains a substantial amount of living biota of which part is lost through melt and export out of the Arctic Ocean every year. It is unclear how populations can be maintained within the Arctic Ocean. A representative ice inhabitant, the amphipod Apherusa glacialis was previously assumed to spend its entire life in the sea ice habita...
Article
Large swarms of individuals at different spatiotemporal scales characterise the distributions of many animal species. In the ocean several mesozooplankton taxa aggregate in large patches or swarms driven by active behavioural responses to hydrographic structures, although intrinsic biotic characteristics of species´ life cycles not related with the...
Article
A comparative study of lipid profile of the daubed shanny Leptoclinus maculatus postlarvae from fjords of different domains (arctic-boreal Kongsfjord and high-arctic Rjipfjord) of Svalbard Archipelago waters in summer was performed. A more efficient accumulation of lipids in the fishes from Kongsfjord compared to Rjipfjord due to triacylglycerols a...
Article
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Effective ocean management requires integrated and sustainable ocean observing systems enabling us to map and understand ecosystem properties and the effects of human activities. Autonomous subsurface and surface vehicles, here collectively referred to as “gliders”, are part of such ocean observing systems providing high spatiotemporal resolution....
Chapter
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The marine pelagic primary production is an important energy source for most Arctic ecosystems, both marine and terrestrial. Single‐celled algae in the water column and in sea ice are at the base of the food web. There are two main drift patterns for sea ice and the upper polar mixed layer in the Arctic Ocean: the Beaufort Gyre (BG) and the Transpo...
Article
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Isfjorden, a broad Arctic fjord in western Spitsbergen, has shown significant changes in hydrography and inflow of Atlantic Water (AW) the last decades that only recently have been observed in the Arctic Ocean north of Svalbard. Variability and trends in this fjord’s climate and circulation are therefore analysed from observational and reanalysis d...
Article
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Recent discoveries of high levels of biological activity in the Arctic marine ecosystems during the polar night raise questions regarding the ecophysiology of the pelagic postlarval daubed shanny Leptoclinus maculatus. Of special interest is the composition of the lipid sac—a unique feature not found in other Arctic fishes. Analysis of the fatty ac...
Chapter
Pelagic communities play a key role in Arctic ecosystems. Although zooplankton occupy several different trophic levels in the food chain, their primary niche is often considered that of a link between pelagic and ice-associated primary production on one side and higher trophic levels on the other. In fact, most of the biological energy (organic car...
Article
Full-text available
The seasonal dynamic of lipids and their fatty acid constituents in the lipid sac and muscles of pelagic postlarval Leptoclinus maculatus, an ecologically important fish species in the Arctic food nets, in Kongsfjord, Svalbard waters was studied. The determination of the qualitative and quantitative content of the total lipids (TLs), total phosphol...
Article
Full-text available
Mesopelagic fish and zooplankton are consistently found in the high Arctic, but their assemblage and trophic relationships change between summer and winter.
Chapter
Zooplankton in Kongsfjorden, Svalbard, is shaped by irregular advection of seawater from the West Spitsbergen Current as well as input of freshwater of glacial and riverine origin. The zooplankton community reflects contributions of Arctic vs. Atlantic water masses in the fjord, and is changing with increasing tem- perature and declining sea ice. H...
Article
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In the original version of the article, the word not is missing in a sentence in the third last paragraph of “Results and discussion”. Please find the corrected sentence here: Leptoclinus maculatus, not being a piscivorous fish, most likely acquire juveniles of Anisakis sp. and Pseudoterranova sp., as well as diphyllobothriid plerocercoids, when fe...
Article
Full-text available
A large amount of warm Atlantic water (AW) enters the Arctic as a boundary current through Fram Strait (West Spitsbergen Current [WSC]) and is the major oceanic heat source to the Arctic Ocean. Along the north-western Svalbard shelf, the WSC splits into the shallow Svalbard Branch, the Yermak Branch that follows the slope of the Yermak Plateau, and...
Article
A fatty acid content of structural (phospholipids, PLs) and storage (triacylglycerols, TAGs) lipids in muscles of daubed shanny Leptoclinus maculatus postlarvae from Kongsfjord (Svalbard archipelago waters) was studied. A high level of monounsaturated fatty acids (MUFAs), mainly due to 20:1(n-9) and 22:1(n-11), was shown in TAGs of daubed shanny mu...
Article
Full-text available
Zooplankton provide the key link between primary production and higher levels of the marine food web and they play an important role in mediating carbon sequestration in the ocean. All commercially harvested fish species depend on zooplankton populations. However, spatio-temporal distributions of zooplankton are notoriously difficult to quantify fr...
Article
Full-text available
The daubed shanny, Leptoclinus maculatus (Fries 1838), is an arctic-boreal fish species and widely distributed in Svalbard waters. The ecological role of L. maculatus is determined by its complex life cycle—adults are bottom-dwelling while the young are pelagic—which indicates its place in the Arctic trophic food webs, both pelagic and benthic. As...
Article
Life cycle and reproduction of Calanus hyperboreus were studied during a year of record low ice cover in the southeastern Beaufort Sea. Stages CIV, adult females and CV dominated the overwintering population, suggesting a 2- to 3-year life cycle. Within two spring-summer months in the upper water column females filled their energy reserves before i...
Article
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Phenological variations of the marine copepod Calanus finmarchicus were studied in Svalbard and northern Iceland, where samples were collected in summer and spring, respectively, over two decades. Four phenological indices, developed for copepodite stage-structured data, were used: the proportion of CV to total abundance (CVT), the population devel...
Article
Full-text available
The daubed shanny Leptoclinus maculatus is a relatively common fish species in Svalbard waters, but little is known about its reproduction. In total, 207 specimens (76 females, 131 males) were collected and examined. Gonadosomatic (GSI) and hepatosomatic indices were significantly higher in females (mean 2.8 and 2.7%, respectively) than males (mean...
Article
Due to retreating sea ice and predictions of undiscovered oil and gas resources, increased activity in Arctic shelf sea areas associated with shipping and oil and gas exploration is expected. Such activities may accidentally lead to oil spills in partly ice-covered ocean areas, which raises issues related to oil spill response. Net Environmental Be...
Article
For oil spill responses, assessment of the potential environmental exposure and impacts of a spill is crucial. Due to a lack of chronic toxicity data, acute data is used together with precautionary assumptions. The effect on the Arctic keystone (copepod) species Calanus hyperboreus and Calanus glacialis populations is compared using two approaches:...
Article
Full-text available
Arctic marine ecosystems support fisheries of significant and increasing economic and nutritional value. Commercial stocks are sustained by pelagic food webs with relatively few keystone taxa mediating energy transfer to higher trophic levels, and it remains largely unknown how these taxa will be affected by changing climate and the influx of borea...
Article
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The patterns of growth and development have been studied in L. maculatus early life stages of different ecological groups (pelagic and demersal) from Kongsfjorden and Billefjorden (the northwestern coast of West Spitsbergen). It has been found that the growth rate of larvae markedly increases by age 2+ (stage L2), which is due to their transition t...
Article
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In the advective realm of the seas, it is challenging to disentangle the role of regional and local processes on zooplankton populations. However, comparative studies of spatially separated zooplankton populations can provide valuable insights into this issue. We studied interannual abundance variation of the key zooplankton species Calanus finmarc...
Article
The content of total phospholipids and their classes (phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, sphingomyelin) of muscles (flesh) and lipid sac of different developmental stages of young fish the daubed shanny, Leptoclinus maculatus from Kongsfjord (Svalbard, Norway) in winter was studied. The content...
Article
The objectives of this study were to explore trophic levels and possible diet overlap between harp seals (Pagophilus groenlandicus) and common minke whales (Balaenoptera acutoroostrata) in the Barents Sea using stable isotopes of nitrogen (δ¹⁵N) and carbon (δ¹³C) and fatty acid analyses, and to explore the energy pathways from the plankton to the t...
Article
Full-text available
The dynamics of lipid and fatty acid composition of the muscles (flesh) and lipid sac in L. maculatus early life stages of different age collected in Kongsfjorden (Svalbard, Norway), in winter, during the polar night was studied. We showed that the total lipid content in the muscles increases on account of energetic triacylglycerols derived from th...
Article
Full-text available
Zooplankton abundance and community structures were studied in three west Spitsbergen fjords at the beginning of the warm phase, which seem to have entered in 2006. Sampling was conducted in summer 2007 at stations distributed along transects in Hornsund, Isfjorden and Kongsfjorden. Variations in zooplankton standing stocks and community structures...
Conference Paper
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The variation of the ice edge position is analyzed and compared with the total solar irradiance (TSI). Autocorrelation of the wavelet spectrum shows stationary periods close to the orbital periods of Saturn, Uranus and Neptun, suggesting a relation.
Article
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Diel vertical migration (DVM) of zooplankton is considered less prominent at high latitudes where diel changes in irradiance are minimal during periods of midnight sun and polar night, leaving zooplankton without a temporal refuge and thus eliminating a key advantage of DVM. One of the shortcomings of previous DVM studies of zooplankton based on ne...
Article
Full-text available
Six and a half month records from three ice-tethered Acoustic Doppler Current Profilers deployed in October 2013 in Young Sound fjord in Northeast Greenland are used to analyze the acoustic backscatter signal. The acoustic data suggest a systematic diel vertical migration (DVM) of scatters below the land-fast ice during polar night. The scatters we...
Poster
Full-text available
Six and a half month time series of acoustic backscatter and velocity from three ice-tethered Acoustic Doppler Current Profilers deployed in the Young Sound fjord in Northeast Greenland were used to analyse the acoustic signal. During period of civil polar night below the land-fast ice, the acoustic data suggest a systematic diel vertical migration...
Poster
Full-text available
Variations of the ice edge has been analyzed and stationary periods close to the orbital periods of Saturn, Uranus and Neptun are found. They appear also in total solar irradiation series. This indicates that there may be a connection between the planets, the Sun, and the position of the ice edge.
Article
The fatty acid (FA) composition has been analysed in the blubber of 56 minke whales caught during the Norwegian commercial whaling period in 2009–2011. Minke whales from four regions were sampled: the North Sea, Vesterålen, Spitsbergen/Bear Island and Finnmark. The FA profiles of the whale blubber have been compared with FA profiles of potential pr...
Article
Full-text available
The current understanding of Arctic ecosystems is deeply rooted in the classical view of a bottom-up controlled system with strong physical forcing and seasonality in primary-production regimes. Consequently, the Arctic polar night is commonly disregarded as a time of year when biological activities are reduced to a minimum due to a reduced food su...
Article
Full-text available
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...
Article
Full-text available
Polar regions are characterized by a strong seasonality in primary production and distinct fluctuations in food supply. The storage of energy in the form of lipids is expected to follow a seasonal pattern; however, year-round observations are lacking. The seasonal variations of lipid classes and fatty acid compositions of four pelagic amphipods hav...
Article
Full-text available
Arctic species of Calanus are critical to energy transfer between higher and lower trophic levels and their relative abundance, and lipid content is influenced by the alternation of cold and warm years. All three species of Calanus were collected during different periods in Kongsfjorden (Svalbard, 79°N) and adjacent shelf during the abnormally warm...
Article
Full-text available
The light regime is an ecologically important factor in pelagic habitats, influencing a range of biological processes. However, the availability and importance of light to these processes in high Arctic zooplankton communities during periods of 'complete' darkness (polar night) are poorly studied. Here we characterized the ambient light regime thro...
Article
Full-text available
Underwater light regime is controlled by distribution and optical properties of Colored Dissolved Organic Matter (CDOM) and particulate matter. The Fram Strait is a region where two contrasting water masses are found. Polar water in the East Greenland Current (EGC) and Atlantic water in the West Spitsbergen Current (WSC) differ with regards to temp...
Article
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Herein we document findings from a unique scientific expedition north of Svalbard in the middle of the polar night in January 2012, where we observed an ice edge north of 82°N coupled with pronounced upwelling. The area north of Svalbard has probably been ice-covered during winter in the period from approximately 1790 until the 1980s, a period duri...
Article
Full-text available
Macrozooplankton (e.g. krill, amphipods and jellyfish) and nekton (e.g. decapod shrimp, squid and fish) are integral parts of pelagic ecosystems, but knowledge of their vertical distributions and migrations during winter at high latitudes is lacking. This study provides the quantification of macrozooplankton and nekton distributions during the pola...
Data
The annual routines and seasonal ecology of herbivorous zooplankton species are relatively well known due to their tight coupling with their pulsed food source, the primary production. For higher trophic levels of plankton, these seasonal interactions are less well understood. Here, we study the mid-winter feeding of chaetognaths in high-Arctic fjo...
Article
Full-text available
The annual routines and seasonal ecology of herbivorous zooplankton species are relatively well known due to their tight coupling with their pulsed food source, the primary production. For higher trophic levels of plankton, these seasonal interactions are less well understood. Here, we study the mid-winter feeding of chaetognaths in high-Arctic fjo...
Article
Full-text available