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Fosså, Jan Helge; Mortensen, Pål B.; Furevik, Dag M.

doi:10.1023/a:1016504430684

Cited by 407 publications

(57 citation statements)

References 18 publications

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“…Using the CR rates obtained here, and considering a ∼22% seafloor coverage (Lindberg, 2004;Kutti et al, 2013), CWCR and sponge grounds account for 78% of the total benthic respiration, and consume 63% of the total OC export flux in the Traena MPA (Slagstad et al, 1999). CWCR habitats cover ∼1671 km 2 of the Norwegian continental shelf (150.000 km 2 , Fossa et al, 2002), while recent ROV observations suggest at least a similar coverage for sponges (Cruise report, R/V Håkon Mosby-cruise #2009615). Using these estimates of seafloor coverage, CWCR and sponge grounds are jointly responsible for 36% of the total benthic respiration on the Norwegian continental shelf, and process 5% of the total primary production in the area (Schluter et al, 2000).…”

Section: Discussionmentioning

confidence: 93%

“…These reef ecosystems are widespread across the deep ocean (Klitgaard and Tendal, 2004;Roberts et al, 2006), but they face an uncertain future, as the human imprint on the deep-sea rapidly increases (Pusceddu et al, 2014). As oil and gas exploration are moving into deeper waters, seafloor installations, accidental oil spilling and sediment plumes are increasingly impacting the reef structures (Purser and Thomsen, 2012;Fisher et al, 2014;Roberts and Cairns, 2014), while physical disturbance by intensified bottom trawling significantly damages the slow growing reefs (Fossa et al, 2002;Althaus et al, 2009;Miller et al, 2012). …”

Section: Introductionmentioning

confidence: 99%

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Cold-water coral reefs and adjacent sponge grounds: hotspots of benthic respiration and organic carbon cycling in the deep sea

et al. 2015

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Cold-water coral reefs and adjacent sponge grounds are distributed widely in the deep ocean, where only a small fraction of the surface productivity reaches the seafloor as detritus. It remains elusive how these hotspots of biodiversity can thrive in such a food-limited environment, as data on energy flow and organic carbon utilization are critically lacking. Here we report in situ community respiration rates for cold-water coral and sponge ecosystems obtained by the non-invasive aquatic Eddy Correlation technique. Oxygen uptake rates over coral reefs and adjacent sponge grounds in the Traena Coral Field (Norway) were 9-20 times higher than those of the surrounding soft sediments. These high respiration rates indicate strong organic matter consumption, and hence suggest a local focusing onto these ecosystems of the downward flux of organic matter that is exported from the surface ocean. Overall, our results show that coral reefs and adjacent sponge grounds are hotspots of carbon processing in the food-limited deep ocean, and that these deep-sea ecosystems play a more prominent role in marine biogeochemical cycles than previously recognized.

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Section: Discussionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Cold-water coral reefs and adjacent sponge grounds: hotspots of benthic respiration and organic carbon cycling in the deep sea

et al. 2015

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“…Table 3 summarizes the effects of fishing and litter on benthic organisms and habitats. Negative effects from bottom trawling have been clearest demonstrated for large megabenthos (corals and sponges; Fosså et al, 2002;Mortensen et al, 2005;Buhl-Mortensen et al, 2016;Buhl-Mortensen, 2017). Buhl-Mortensen (2017) studied the health status of Lophelia reefs off northern Norway in relation to bottom trawling, and found minimal damage on coastal reefs where little bottom trawling occurs, whereas extensive damage was documented on offshore reefs, exposed to greater FI.…”

Section: Impacts Of Bottom Trawlingmentioning

confidence: 99%

Impacts of Bottom Trawling and Litter on the Seabed in Norwegian Waters

Buhl-Mortensen

Buhl‐Mortensen

2018

Front. Mar. Sci.

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Bottom trawling and seabed littering are two serious threats to seabed integrity. We present an overview of the distribution of seabed litter and bottom trawling in Norwegian waters (the Norwegian Sea and the southern Barents Sea). Vessel Monitoring System (VMS) records and trawl marks (TM) on the seabed were used as indicators of pressure and impact of bottom trawling, respectively. Estimates of TM density and litter abundance were based on analyses of seabed videos from 1,778 locations, surveyed during 23 cruises, part of the Norwegian seabed mapping programme MAREANO. The abundance and composition of litter and the density of TM varied with depth, and type of sediments and marine landscapes. Lost or discarded fishing gear (especially lines and nets), and plastics (soft and hard plastic and rubber) were the dominant types of litter. The distribution of litter reflected the distribution of fishing intensity (density of VMS records) and density of TM at a regional scale, with highest abundance close to the coast and in areas with high fishing intensity, indicated from the VMS data. However, at a local scale patterns were less clear. An explanation to this could be that litter is transported with currents and accumulates in troughs, canyons, and local depressions, rather than reflecting the fisheries footprints directly. Also, deliberate dumping of discarded fishing gear is likely to occur away from good fishing grounds. Extreme abundance of litter, observed close to the coast is probably caused by such discarded fishing gear, but the contribution from aggregated populations on land is also indicated from the types of litter observed. The density of trawl marks is a good indicator of physical impact in soft sediments where the trawl gear leaves clear traces, whereas on harder substrates the impacts on organisms is probably greater than indicated by the hardly visible marks. The effects of litter on benthic communities is poorly known, but large litter items, such as lost fishing gear may add to the direct negative effects of bottom trawling.

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“…Bottom trawling is probably one of the largest anthropogenic threats to CWCs (Fosså et al, 2002;Hall-Spencer et al, 2002;Benn et al, 2010) and this fishing activity is increasing on the rims of canyons (Martín et al, 2014b). Trawl gear can damage CWC communities by reducing or changing coral abundances, diversity and community or the removal of structuring species (reviewed by Clark et al, 2016), as shown for coral reefs of the NE Atlantic (Hall-Spencer et al, 2002) and Solenosmilia thickets on Australian seamounts (Althaus et al, 2009).…”

Section: Threats and Canyons As Refuges For Cwc Habitatsmentioning

confidence: 99%

Cold-Water Coral Habitats in Submarine Canyons of the Bay of Biscay

et al. 2017

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The topographical and hydrological complexity of submarine canyons, coupled with high substratum heterogeneity, make them ideal environments for cold-water coral (CWC) habitats. These habitats, including reefs, are thought to provide important functions for many organisms. The canyons incising the continental slope of the Bay of Biscay have distinct morphological differences from the north to the south. CWCs have been reported from this basin in the late nineteenth century; however, little is known about their present-day distribution, diversity and environmental drivers in the canyons. In this study, the characteristics and distribution of CWC habitats in the submarine canyons of the Bay of Biscay are investigated. Twenty-four canyons and three locations between adjacent canyons were sampled using a Remotely Operated Vehicle (ROV) or a towed camera system. Acquired images were annotated for habitat type (using the CoralFISH classification system), substrate cover and coral identification. Furthermore, the influence of hydrological factors and geomorphology on the CWC distribution was investigated. Eleven coral habitats, formed by 62 morphotypes of scleractinians, gorgonians, antipatharians and seapens, inhabiting hard and/or soft substrate, were observed. The distribution patterns were heterogenous at regional and local scales; the south Bay of Biscay and the southeastern flank favored soft substrate habitats. Biogenic and hard substrate habitats supported higher coral diversities than soft substrate habitats and had similar species compositions. A higher coral species turnover characterized soft substrate habitats. Substrate type was the most important driver of the patterns in both distribution and composition. Observations of coral reefs on steeper areas in the canyons and coral rubble on flatter areas on the interfluve/upper slope support the hypothesis that canyons serve as refuges, being less accessible to trawling, although natural causes may also contribute to the explanation of this distribution pattern. The results of this study fed into a proposal of a Natura 2000 network in the Bay of Biscay where management plans are rare.

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Cited by 407 publications

References 18 publications

Cold-water coral reefs and adjacent sponge grounds: hotspots of benthic respiration and organic carbon cycling in the deep sea

Cold-water coral reefs and adjacent sponge grounds: hotspots of benthic respiration and organic carbon cycling in the deep sea

Impacts of Bottom Trawling and Litter on the Seabed in Norwegian Waters

Cold-Water Coral Habitats in Submarine Canyons of the Bay of Biscay

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