IMIS

The working group on mackerel and horse mackerel egg surveys (WGMEGS) coordinates the Mackerel and Horse Mackerel Egg Survey in the Northeast Atlantic and the Mackerel Egg Survey in the North Sea, both which are carried out triennially. Eggdata collected from both surveys provide an indices for the strength of the SSB of both the western and North Sea stocks of Atlantic mackerel (Scomber scombrus) and a relative abundance index of horse mackerel (Trachurus trachurus) spawning stocks in the Northeast Atlantic. The surveys are divided into 3 geogr aphical component areas, the western, southern and the North Sea. In the western area the mackerel egg survey has been running continuously on a triennial basis since 1977 and since 1992 has also sampled the southern spawning component. It typically takes place between February and July and aims to cover the entire spawning area from Cadiz in the south up as far as NW Scotland in the North and since 2010 up to the waters around the Faroe Islands and southeast of Iceland. The egg survey in the North Sea has been running since 1968.

A comprehensive description of the survey protocols, analysis techniques together with the methods used for calculating the egg abundance estimates can be found in the WGMEGS survey manual which is contained within Annex 5 of the 2 012 WGMEGS