CE17017 Irish Groundfish Survey Leg 2

This survey was conducted on board the RV Celtic Explorer in 2017 by the Marine Institute (MI) as part of the annual groundfish survey to determine the distribution and abundance of commercial fish around Ireland. The Irish Groundfish Survey (IGFS) forms part of the International Bottom Trawl Survey (IBTS) programme, an international survey effort coordinated by the International Council of the Exploration of the Sea (ICES). Each year the survey, taking place in Autumn/Winter, collects demersal trawl and ancillary data in Irish waters to produce relative abundance indices for fisheries management. In particular the survey provides an index of the share of young fish in the stock, which in turn gives an indication of its spawning success. The IGFS contributes to Ireland’s international obligation to supply scientific data that support the implementation of the Common Fisheries Policy (CFP). In Irish waters, France and Ireland survey the Celtic Sea area, Ireland surveys the shelf West of Ireland, Ireland and the UK Scotland cover the north coast of Ireland and the UK and Northern Ireland survey the Irish Sea. This survey is a series of demersal sampling trawls at pre-defineds stations. The 2017 survey took place over 2 legs. Leg 1 focused on the northerly ICES Area and took place in October, while Leg 2 in the western and mainly southern areas was carried out from 5th November to 9th December. The western areas were not as extensively surveyed in 2017 due to difficulties with the neighbouring EVHOE survey (conducted by France). This resulted in number of days being allocated to completing 22 hauls south of the normal IGFS survey range. Time was allocated mostly from ICES areas 7bc. In order to make data as comparable as possible, each survey operates under a set of agreed standard protocols. Each tow is 30min long and takes place during daylight hours at 3.5-4 knots. Net geometry and ground contact is monitored and logged. All fish and commercial shellfish are sorted to species level prior to taking lengths and other biological measurements such as age, sex and maturity. Additional oceanographic data on conductivity, temperature and depth (CTD) was also collected. The primary purpose of the Irish Groundfish Survey is to develop estimates of juvenile abundances for important commercial fish species. Measurements of the abundance of juvenile fish are a critical measure of the health of a stock, serving as an annual indication of recruitment (the number of newly spawned fish which enter the population each year) success or failure. Most importantly, they allow forecasting of future commercial abundance. In addition, the Irish Groundfish Survey provides data on the distribution and biology of commercial and non-commercial species of ecological interest, as well as hydrographic and environmental observations.