Blue Whiting Acoustic Survey Cruise Report Spring 2007

Abstract

Acoustic surveys on the blue whiting (Micromesistius poutassou) stock in the north east Atlantic have been carried out since the early 1970s by the Institute of Marine Research (IMR), Norway. In the early 1980s a coordinated acoustic survey approach was adopted, with both Russia and Norway participating to estimate the size of this migratory stock within its key spawning grounds. Since 2004, the coordinated survey program has expanded and now includes vessels from the Netherlands, Faroes and Ireland in addition to those from the Russian Federation and Norway. Due to the highly migratory nature of the stock, a large geographical area has to be surveyed. Spawning takes place from January through to April, with a peak time between mid-March and early April. Consequently acoustic surveys are routinely carried out during the peak spawning period within known geographic confines. To facilitate a more coordinated spatiotemporal approach to this spawning stock survey, participating countries meet annually to discuss survey methods and define target areas at the ICES led Planning Group of Northern Pelagic Ecosystem Surveys (PGNAPES). Data from the annual spawning stock abundance survey (March/April), juvenile surveys (May) and commercial landings data are presented annually at the ICES led Northern Pelagic and Blue Whiting Fisheries Working Group (WGNPBW). Ultimately, combined data inputs into the management and catch advice for this cross boundary stock. The 2007 survey was part of an International collaborative survey using the vessels RV “Celtic Explorer” (Marine Institute, Ireland), RV “Atlantida” (AtlantNIRO, Russian Federation), RV “Tridens” (IMARES, Netherlands) and the RV “Magnus Heinason” (FRS, Faroes) and the FV “Eros” (IMR commercial charter). The total combined area coverage in 2007 extended from the Faroe Islands in the north (61.30°N) to south of Ireland (50.30°N), with east –west extension from 5°-19° W. Combined area coverage included shelf break areas (>200m) and large bathymetric features including the Porcupine, Rockall and Hatton Banks. The Irish component of the survey was made up of transects covering 2,624 nmi (nautical miles) covering the north Porcupine area, the eastern and western fringes of the Rockall Bank and the western slopes of the Hatton Bank. This survey represents the 4th survey in the Irish time series.