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  • 1
    Publication Date: 2018-08-24
    Description: In a bid to further understand processes that influence deep-sea epibenthic megafauna, which fulfil critical roles in the global carbon cycle, we present data from the Arctic Long-Term Ecological Research observatory HAUSGARTEN, in the Fram Strait, showing significant temporal changes in total biomass of 3 key organisms (Kolga hyalina, Elpidia heckeri and Mohnia spp.) at stations N3, HG-IV and S3 during repeated deployments over a time series spanning 2004−2015. Overall, all species investigated displayed a similar reproduction/recruitment cycle, with increasing mean mass per individual leading to decreases in abundance, and vice versa. However, there were 3 ‘events’ that deviated from this pattern. The first was a mass reproduction event of E. heckeri at HG-IV from 2012 onwards, likely due to an increased carrying capacity. The second event involved migration of K. hyalina from HG-IV between 2004−2007, with a return in 2011. This coincided with a shift in the composition of the particle flux at the station. The final event was a mass migration of K. hyalina to N3 between 2004 (0 ind. m−2) and 2007 (4.765 ± 0.084 ind. m−2). This event coincided with a 4-fold increase in phytodetrital food availability at the seafloor at N3. Our results highlight the importance of time-series studies to ascertain the key factors that influence epibenthic megafaunal communities. It also highlights the fact that more needs to be done in understanding the life history of these organisms, as this understanding is, so far, widely lacking.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 2
    Publication Date: 2014-10-07
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 3
    Publication Date: 2018-02-23
    Description: One of the recently recognised stressors in Arctic ecosystems concerns plastic litter. In this study, juvenile polar cod (Boreogadus saida) were investigated for the presence of plastics in their stomachs. Polar cod is considered a key species in the Arctic ecosystem. The fish were collected both directly from underneath the sea ice in the Eurasian Basin and in open waters around Svalbard. We analysed the stomachs of 72 individuals under a stereo microscope. Two stomachs contained non-fibrous microplastic particles. According to µFTIR analysis, the particles consisted of epoxy resin and a mix of Kaolin with polymethylmethacrylate (PMMA). Fibrous objects were excluded from this analysis to avoid bias due to contamination with airborne micro-fibres. A systematic investigation of the risk for secondary micro-fibre contamination during analytical procedures showed that precautionary measures in all procedural steps are critical. Based on the two non-fibrous objects found in polar cod stomachs, our results show that ingestion of microplastic particles by this ecologically important fish species is possible. With increasing human activity, plastic ingestion may act as an increasing stressor on polar cod in combination with ocean warming and sea-ice decline in peripheral regions of the Arctic Ocean. To fully assess the significance of this stressor and its spatial and temporal variability, future studies must apply a rigorous approach to avoid secondary pollution.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 4
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    INTER-RESEARCH
    In:  EPIC3Marine Ecology-Progress Series, INTER-RESEARCH, 556, pp. 45-57, ISSN: 0171-8630
    Publication Date: 2017-01-31
    Description: Stones released by melting icebergs are called dropstones, and these stones constitute island-like hard-bottom habitats at high latitudes. In 2012, dropstone megafauna in the HAUSGARTEN observatory in the Fram Strait was sampled photographically. We tested the hypothesis that dropstones would have the same species distribution patterns as terrestrial islands, using 5 patterns commonly found in the classical island literature. Higher richness, diversity, and abundance of fauna occurred on larger stones and on stones near a deep-water rocky reef. These patterns can be explained by the greater surface area of larger stones, the exposure of larger stones to faster current higher in the benthic boundary layer, and increased larval supply from the rocky reef. Some pairs of morphotypes (12 pairs out of 56 morphotypes and 1540 possible pairs) co-occurred less often than expected by chance. While similar patterns have been attributed to interspecific competition in the classical island literature, we offer alternative mechanisms for dropstones. Non-random co-occurrence on dropstones may be explained by larval dispersal. Dropstone fauna had an overdispersed (clumped) distribution, so pairs of morphotypes may have negative non-random co-occurrence simply because short larval life and limited dispersal ability prevent them from having randomly overlapping distributions. In addition, we found 8 morphotype pairs that co-occurred more often than expected by chance because of epibiontism. The patterns found in dropstone communities resemble terrestrial islands, but different mechanisms may be responsible.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 5
    Publication Date: 2015-11-27
    Description: Although recent reports indicate that anthropogenic waste has made it to the remotest parts of our oceans, there is still only limited information about its spread, especially in polar seas. Here, we present litter densities recorded during ship- and helicopter-based observer surveys in the Barents Sea and Fram Strait (Arctic). Thirty-one items were recorded in total, 23 from helicopter and eight from research vessel transects. Litter quantities ranged between 0 and 0.216 items km−1 with a mean of 0.001 (±SEM 0.005) items km−1. All of the floating objects observed were plastic items. Litter densities were slightly higher in the Fram Strait (0.006 items km−1) compared with the Barents Sea (0.004 items km−1). More litter was recorded during helicopter-based surveys than during ship-based surveys (0.006 and 0.004 items km−1, respectively). When comparing with the few available data with the same unit (items km−1 transect), the densities found herein are slightly higher than those from Antarctica but substantially lower than those from temperate waters. However, since anthropogenic activities in the Fram Strait are expanding because of sea ice shrinkage, and since currents from the North Atlantic carry a continuous supply of litter to the north, this problem is likely to worsen in years to come unless serious mitigating actions are taken to reduce the amounts of litter entering the oceans.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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