Fosså, Jan Helge; Arnøy, Ole Oskar; Skadal, Janicke; Gamst, Kjell Arne; Johannesen, Edda (2011): Length and mass measurements of individual fish and sponges from long line fishing onboard the fishing vessel Øyfisk during cruise IMR-2009813 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.756324

The objective of the IMR-2009615 cruise was to study the distribution of fish and plankton in relation to the occurrence of Lophelia cold-water coral reefs and the general topography in the Traena Deep coral reef field. Geographic areas (2 x 2 km) for long-line fishing were selected on the basis of multi-beam bathymetric maps. This included two plots with high density of coral reefs, two plots with low density of coral reef and two plots without any Lophelia reefs (however the area contained high densities of large sponges). Fishing was carried out by the coastal long-liner M/V Øyfisk. During a 5 day period a total of 22 fleets of long-line were set, each containing approximately 1280 hooks. The hooks were baited with squid. Soak time was approximately 4 hours. Fishing was performed with no consideration to what time of the day the lines were set since in June there is light 24 h a day. four fleets of long line were set across each plot. Setting direction was parallel with the main current direction at the site and perpendicular to the depth contour. Starting position for the first line was selected randomly from 0 to 1000 m away from the western up-current side of the plot. The second line was set 900 m away from the first one to avoid that one line would "steal" fish from the other. Fishing was carried out two times in each block, the second time with a new randomly selected starting position. Catch was registered per 250 m sub-section of the line (160 hooks). All fish was identified, weighed and length determined and analyzed for sex and degree of maturity. Stomachs were collected whenever possible. From each subsection of the line otoliths were collected for age determination for a maximum of 10 individuals per fish species. By-catch of sponges and corals were registered.