IMIS

In the Northern Ireland survey, the sampling design is stratified with fixed-position stations. Stratification is by depth and seabed type. Haul duration is 3 nautical miles at 3 knots over the seabed. Stations in the St George's Channel are 1 nautical mile at 3 knots and have only been surveyed since October 2001. Number of stations is 45 in northern Irish Sea and 12 in St George's Channel. Tows are during day time only. The surveys have been carried out in March and October since 1992. From March 1992 to March 2001, the survey extended from 54° 43' N to 53° 22' N. From October 2001 the survey is extended into the St George's Channel to 52° 18' N. Depth range is from 20 to 120m. The surveys are carried out on the R.V. Lough Foyle, a 43.5m stern trawler of 880 kw and GRT 547 tonnes. The fishing gear is a rock-hopper otter trawl with a 17m footrope fitted with 250 mm non-rotating rubber discs. The gear has a mean vertical opening of 3 m. The door spread varies from around 25m at 20m depth to 40m at 80m depth. A 20mm (inside mesh) codend is fitted.