• Blue Whiting Acoustic Survey Cruise Report March-April 2005

      O’Donnell, Ciaran; Mullins, Eugene; Power, Gavin; Goddijn, Lonneke; Mackey, Mick (Marine Institute, 2005)
      Acoustic surveys on northern blue whiting (Micromesistius poutassou) stocks have been carried out since the early 1970s by the Institute of Marine Research (IMR), Bergen. In the early 1980s a coordinated acoustic survey approach was adopted, with both Russia and Norway participating to estimate the size of the stock. The acoustic survey programme is carried out for fishery management purposes, results are presented annually at the ICES led Northern Pelagic and Blue Whiting Fisheries Working Group and from this catch advice is determined for the following year. The highly migratory nature of this stock and its components require a large geographical area to be surveyed during a relatively short spawning window. Acoustic surveys are routinely carried out on specific spawning and pre-spawning aggregations of blue whiting. This can allow for high concentrations of fish to be surveyed in a relatively small geographical and often well defined area, if the timing is synchronised. This survey was conducted as part of a collaborative survey coordinated by the Institute of Marine Research, Bergen, Norway, using the vessel the RV “G.O. Sars”. Also participating were the RV “Fridtjof Nansen” (PINRO, Russia), RV “Atlantniro” (Russia), RV “Tridens” (RIVO, Netherlands) and the RV “Magnus Heinason” (Faroes). The total combined area surveyed in 2005 covered from the Faroe Islands in the north (62º of longitude) to the southern coast of Ireland (49º N), area coverage to the west extended from 2º -20º of latitude. The Irish component of the survey was made up of transects covering some 2,228 nautical miles. In addition to the collection of acoustic data fishing hauls were carried out to determine the make up of fish marks recorded by the equipment and to assess the length, weight, age, sex and maturity of the stock. Oceanographic data was collected using a number of spaced hydrograhic stations where salinity and temperature of the water column was recorded at depths of up to 1200 m.
    • Blue Whiting Acoustic Survey Cruise Report March-April 2006

      Mullins, Eugene; Johnston, Graham; Power, Gavin; Goddijn, Lonneke; Mackey, Mick (Marine Institute, 2006)
      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 the combined stock. The acoustic survey programme is carried out for fishery management purposes and is continued to date. Results of this annual spawning stock assessment combined with juvenile surveys and commercial catch at age data are presented annually at the ICES led Northern Pelagic and Blue Whiting Fisheries Working Group. Ultimately, from this combined scientific data, management and catch advice is determined for the following year. The highly migratory nature of the combined stock requires a large geographical area to be surveyed during a protracted spawning period. Consequently Acoustic surveys are routinely carried out on specific spawning and post-spawning aggregations of blue whiting. To facilitate a more coordinated spatio-temporal approach to spawning stock assessment, several nations became involved in the PGNAPES coordinated survey programme in 2004. Ireland is one of these nations involved in this annual survey. The 2006 survey was part of an International collaborative survey coordinated by the Institute of Marine Research, Bergen, Norway, using the vessel the RV “G.O. Sars”. Also participating were the RV “Atlantniro” (Russia), RV “Tridens” (RIVO, Netherlands) the RV “Magnus Heinason” (Faroes) and RV “Celtic Explorer” (Ireland). The total combined area surveyed in 2006 covered from the Faroe Islands in the north (62°of longitude) to the southern coast of Ireland (51° N), area coverage to the west extended from 4°-18° of latitude. The Irish component of the survey was made up of transects covering some 2,632 nautical miles (Figure 1). In addition to the collection of acoustic data, fishing hauls were carried out to determine the make up of fish marks recorded by the equipment and to assess the length, weight, age, sex and maturity of the stock. Oceanographic data was collected using a number of spaced hydrograhic stations where salinity and temperature of the water column was recorded at depths down to 800m.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2004

      O'Donnell, Ciaran; Griffin, Karen; Clarke, Maurice; Lynch, Deirdre; Ulgren, Jenny; Goddijn, Lonneke; Wall, David; Mackey, Mick (Marine Institute, 2004)
      In the Celtic Sea and ICES Division VIIj, to the south and southwest of Ireland, herring is an important commercial species and currently Ireland is the only country targeting this species in this area. Herring in this region comprise both autumn and winter spawning components. Commercial fishing has targeted the fish during spawning times, though in most recent years fish have been targeted during the summer feeding phase too. In VIIj, fishing has traditionally taken place in October, and concentrated in the bays and inlets. In contrast, fishing in VIIaS has mainly been in December to January, though in VIIg the fishery traditionally takes place from November to January. The protracted spawning period of herring and the overlap between the two spawning socks in this area (October to February) means that it is difficult to design a survey that covers all spawning fish in one specific survey. The stock structure and discrimination of herring in this area is not fully understood. It is known that fish in the eastern Celtic Sea recruit from nursery areas in the Irish Sea and tagging studies have shown linkages between these areas also. For the purpose of stock assessment and management these areas have been combined since 1982. A project is currently underway to describe stock structure and discrimination of herring around Ireland. The results of this project may have implications for the design of this survey and for the stock assessment. For a period in the 1980’s, egg and larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and the current survey is the 15th in the series. In addition to the survey track a small component (Baginbun) was intensively surveyed using acoustic and multibeam mapping techniques. The Baginbun area is located east of Waterford Harbour in ICES division VIIaS. Baginbun has supported a large winter fishery for many years and is one of the most important and well known winter spawning areas on the south coast. This year for the first time the RV Celtic Explorer was to survey the area. This allowed a more extensive degree of coverage in the time allocated, the survey was further complemented with a number of hydrographic transects concentrating along the bays in the west and southwest and also along the southern coastline.