Working Group on Mackerel and Horse Mackerel Egg Surveys

The Working Group addressed the problem of estimating the spawning stock sizes of mackerel and horse mackerel in the western spawning area (VI, VII, VIIIa,b,d,e) and the southern spawning area (VIIIc and IX a). As in the previous years the annual egg production method was implemented, using international egg surveys conducted in 2001 between January 11 and July 23 and associated estimates of fecundity and atresia. The sampling was completed as planned, and the Working Group concluded that in 2001 the temporal and spatial coverage for the plankton sampling was very good. Also, the sampling for fecundity and atresia was much better than in 1998. With a total of more than 380 ship days the entire survey effort was nearly 40% higher than in the previous one.The ICES Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS) met in Dublin on April 16-20, under the chairmanship of Dr. Cornelius Hammer, to analyse the data from the 2001 Mackerel and Horse Mackerel Egg Survey. This survey takes place triennially under the participation of Portugal, Spain, England, Scotland, Ireland, The Netherlands, Norway and Germany. The basis of the survey is to relate the number of freshly spawned eggs found in the water with the number of females having produced these eggs. Knowing the fecundity of the females it renders an estimate for the spawning stock biomass. Now the large number of samples has been analysed and the group met to evaluate the results and to assess the size of the mackerel and horse mackerel stocks in the NE Atlantic.