Distribution patterns of deep-sea fish and benthic invertebrates from trawlable grounds of the Hatton Bank, north-east Atlantic: effects of deep-sea bottom trawling

Abstract

Distributions of deep-sea fish, benthic invertebrates and the effects of deep-sea bottom trawling were studied based on data collected in 2005 from a joint collaboration survey undertaken between the Spanish Institute of Oceanography and a deep-sea trawler on the Hatton Bank (north-east Atlantic). A total of 163 valid bottom trawl hauls (600–1600 m) were analysed. The main trawlable grounds were located on the sedimentary seabed of the western flank of the bank (Hatton Drift). Grenadiers and smoothheads were predominant in the trawl catches (67% and 11.8% by weight respectively). Both species were abundant along the western flank. Deep-water sharks accounted for 7.4% of weight, and were abundant along the south-eastern slopes. Chimerids, lotids, morids and other deep-sea species were also taken as by-catch. Grenadiers and deep-water sharks dominated the discards. By-catches of cold-water corals were generally associated with the rocky outcrop and were more abundant at the top of the bank. Abundant by-catches of large sponges, characteristic of sponge-dominated biotopes, were taken from the eastern flank.

Distribution of Deep-Sea Sponge Aggregations in an Area of Multisectoral Activities and Changing Oceanic Conditions

“…Sherwin et al, 2006) and trawl marks could have been erased. In addition, fishermen may intentionally now avoid the FSC NCMPA sponge aggregations in order to limit damage to fishing gear or due to relatively little fish biomass present in sponge aggregations (e.g., see Munoz et al, 2012;Kenchington et al, 2013;Kutti et al, 2014). Present findings on sponge richness/diversity and bodysize distribution are a strong indication about the presence inside the FSC NCMPA of more favorable conditions for reproduction, recruitment and growth of sponges.…”

Cold-water corals and deep-sea sponges by-catch mitigation: Dealing with groundfish survey data in the management of the northwest Atlantic Ocean high seas fisheries

“…Corals and sponges, as erect and fragile invertebrates, are especially vulnerable to bottom fishing-induced impacts. Particularly, bottom fishing gears can catch unwanted and non-targeted cold-water corals and deep-sea sponges when their spatial distributions overlap with the fishing footprint [2,3].…”

“…In this case, catch data collected from groundfish surveys are being annually updated for assessment of significant concentrations of cold-water corals and deep-sea sponges, underpinning the advice on area closures. 3 Of the above mentioned 14 closures adopted [12], a total of 11 closed areas were located within the Flemish Cap (Division 3 M), which indicates the relevance of the EU groundfish survey data.…”

A Multi Criteria Assessment Method for Identifying Vulnerable Marine Ecosystems in the North-East Atlantic

“…Scientific data on the presence of coral at Rockall dates back to the 1970s (Wilson, 1979) and a spate of recent surveys have revealed the occurrence of coral mounds (Wienberg et al, 2008; Durán Muñoz et al, 2009), cold seep ecosystems (Neat et al, 2018), and other important geomorphological features throughout the area (Roberts et al, 2008;Sayago-Gil et al, 2010). In addition, several VME indicator species including cold-water corals and sponges have been identified in recent years through collaboration with commercial trawl and longline fisheries , Durán-Muñoz et al, 2012b. Thus the variable amount of information for this area and the range in quality of that information (e.g., fishing records vs. scientific observations), serves as a good case study to illustrate the approach.…”

“…Techniques developed to identify VMEs could therefore inform what statistical power and effect size should be used to detect VMEs in future broad-scale surveys. Currently, larger amounts of data on VME indicator taxa occurrences across large spatial scales may be available from bycatch records from fisheries surveys (e.g., Murillo et al, 2011Murillo et al, , 2012Portela et al, 2012), cooperative surveys , 2012b and commercial fishing operations. The problem in using bycatch data to inform on the presence of VMEs lies in the fact that bottom fishing gear are poor sampling tools for VME indicator organisms and that bycatch data may not represent the true benthic community composition and densities (Auster et al, 2011).…”