CE0713 Herring Biomass Assessment Survey

This survey was conducted by the Marine Institute on board the R.V. Celtic Explorer in autumn 2007 to survey the Abundance and distribution of herring In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j). Here, herring is an important commercial species to the pelagic and polyvalent fleet. The stock is composed of both autumn and winter spawning components and the fishery targets pre-spawning and spawning aggregations. The autumn 2007 survey covered the area from Loop Head in ICES Division VIIb in Co. Clare and extended south along the western seaboard covering the main Bays and inlets in Divisions VIIj & VIIg. The survey started in the north and worked in a southerly direction to facilitate Temporal Progression of spawning within stock components. Acoustic data were collected using the Simrad ER60 scientific echosounder. A single pelagic midwater trawl with the dimensions of 19 m in length (LOA) and 6 m at the wing ends and a fishing circle of 330 m was employed during the survey. All components of the catch from the trawl hauls were sorted and weighed; fish and other taxa were identified to species level. stations were carried out during the survey at predetermined locations along the track. Oceanographic (CTD) stations were carried out during the survey at predetermined locations along the track. Visual observations for marine mammals and seabirds were conducted during Daylight hours.