Preface The expedition ARK XIX/3 with the German icebreaking RV ...

A. 4.8.4 Fisheries Impact Studies on the Porcupine Seabight and Bank
Grehan, A., Unnithan, V., Guinan, J., Wilson, M.
Previous detailed ROV surveys conducted during 2001 at mound sites in the
Porcupine Seabight and the Rockall Trough revealed limited evidence of fisheries
impacts in areas where there were corals (Grehan et al. 2003). Lost static gears were
imaged in the Belgica and Pelagia mound province.
The more extensive surveys during ARK XIX/3a particularly along the western edge of
the Porcupine Bank of "Twin mounds", "Giant mounds" and "Scarp mounds" have for
the first time demonstrated that destructive trawl damage to corals does occur in Irish
waters. A recently lost trawl was imaged at "Giant mounds" full of coral and associated
fauna. Some specimens of Lophelia were clearly still alive attesting to the recent
nature of the impact. Areas of the "Twin mounds" appeared heavily trawled. This was
evident not only from lost nets, but also from scar marks left by the passage of trawl
doors. A number of box cores were taken at this site to assess impacts on biodiversity.
There were numerous examples of lost static gear all along the scarp face snagged on
corals and other protrusions. These did not in most cases appear to have been
dragged but may have been sweep over the ledges by the strong bottom currents in
the area.
References
Grehan, A. J., Unnithan, V., Olu, K. and Opderbecke, J. 2003. Fishing impacts on Irish deepwater
coral reefs: making the case for coral conservation. In: J. Thomas & P. Barnes (eds)
Proceeding from the Symposium on the Effects of Fishing Activities on Benthic Habitats:
Linking Geology, Biology, Socioeconomics and Management, American Fisheries Society,
Bethesda, Maryland, USA.
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