The Norwegian in-year monitoring fishery for sandeel in the North Sea using satellite-based VMS data and landings information

Abstract

Due to the critically poor status of the sandeel stock in the North Sea, the Norwegian Ministry of Fisheries and Coastal Affairs decided to conduct a monitoring fishery in April/May 2006 with a limited number of Norwegian commercial vessels. An eventual re-opening of the sandeel fishery (in the Norwegian Economic Zone) was to be based on the results from the monitoring fishery. It was later decided that the monitoring fishery should take place in week 16-18. One of the main goals with the monitoring fishery is to obtain an estimate of the strength of the 2005 year class (since age 1 is the most important age group in the fishery). This requires estimation of a relationship between Catch Per Unit Effort (CPUE) and abundance. Logbooks from the Norwegian sandeel fleet are not recorded electronically and it is therefore difficult to perform traditional CPUE calculations. However, data from the Norwegian satellite-based vessel monitoring system (VMS) can be used to measure effort, and CPUE can then be estimated by combining VMS and landings data (which exist electronically on trip level). In this work, some of the preliminary analyses conducted in advance of the monitoring fishery are presented. The correlation between estimated CPUE of age 1 (based on VMS data) and estimated abundance of age 1 (from the latest ICES assessment) was positive and significant (p < 0.05) for the years 2001-2005.