This is a new survey which began in December 2006 and extends from the waters to the south west of Ireland, the Porcupine Bank and the North West of Ireland. It is conducted in close collaboration with colleagues from the Marine Laboratory, Aberdeen who survey the west coast of Scotland, the Rockall Bank and into the Northern North Sea.
Purpose of the Survey
The objective is to provide an estimate of the total weight of the highly valuable Anglerfish stocks and to provide information on how the stock changes from year to year. Ultimately, this information is presented to the ICES stock assessment working groups and will form an important source of information for future fisheries advice.
How the survey works
Unlike the other surveys conducted by FSS, which in recent years use the research vessels Celtic Explorer and Celtic Voyager, the Anglerfish survey is conducted using commercial fishing vessels and trawls. Both the survey design and equipment were selected with full industry consultation. The trawls used by the Marine Institute and the Marine laboratory in Aberdeen are identical, and the vessels are similar in size and engine power; this allows direct comparisons to be made between the Irish and Scottish surveys.
The surveys are conducted towards the end of the year and are therefore susceptible to winter storms - but this is the optimum time to catch anglerfish. Four different depth zones (strata) are surveyed, 0 – 140 m; 140 – 200 m; 200 – 500 m and 500 – 1000 m, a larger amount of survey time is spent in the 140 - 200 m zone as this is known to contain the highest concentrations of Anglerfish. In addition to collecting biological data, a number of anglerfish from each haul are tagged and released to provide information on migration patterns and growth rates.
Recent Survey Results
As this survey is in its infancy, it is too early to draw any conclusions from the recent information. The data is currently being analysed and will be compared with other sources of information from commercial landing statistics and the annual Irish Groundfish Survey (IGFS) to provide a clearer picture of this highly important stock.