Browsing Survey & Cruise Reports by Author "Ullgren, J"
Blue Whiting Acoustic Survey Cruise Report Spring 2007O'Donnell, C; Mullins, E; Johnston, G; Beattie, S; Ullgren, J; Heino, M; Anthonypillai, V (Marine Institute, 2007)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.
Celtic Sea Herring Acoustic Survey RV Celtic Explorer 1st – 21st October 2006O'Donnell, C; Doonan, I; Lynch, D; Egan, A; Boyd, J; Wall, D; Ullgren, J (Marine Institute, 2006)In the Celtic Sea and ICES Division VIIj the herring fishery is divided into 3 main catching seasons. In quarters four and one, the fishery is focused on autumn and winter pre-spawning and spawning aggregations. In the 2004/05 season 34 vessels participated in the fishery, ranging from small dry hold polyvalent vessels (<20m) to purpose built RSW (Refrigerated seawater) vessels of 23-40m. Single and pair midwater trawling are common, with the latter representing the preferred catching method. In recent years a quarter-3 summer fishery has developed targeting offshore feeding aggregations, 78nmi (nautical miles) offshore on the Labadie Bank. This offshore fishery is restricted to the RSW fleet on the grounds of product quality delivered to processors. The 2006 autumn survey is the most comprehensive survey carried out in the current time series. The geographical extent of the annual 21 day survey was extended further offshore to include areas to the south of the main coastal spawning grounds to target winter spawning fish on an inward spawning migration. Spatial resolution of acoustic transects were increased over the entire south coast survey areas, with a special focus on spawning grounds throughout the survey confines. The acoustic component of the survey was complimented by a continuation of the detailed hydrographic work first established in the Celtic Sea in 2004.