Acoustic Survey Stations

Acoustic surveys have been generally carried out on spawning and pre-spawning aggregations of fish. Outside of the spawning season many pelagic species have been generally very scattered over a large geographical area and difficult to detect using acoustic methods. A cruise track was first formulated with data from previous surveys, commercial catch data and the help of the fishermen and fishing industry. This is the spatial dataset of the acoustic survey haul station locations undertaken during surveys. Acoustic surveys have taken place in the North Atlantic Ocean between Donegal and the west coast of Scotland; and in the Celtic Sea off the south coast of Ireland. Acoustic surveys have taken place on an annual frequency since 1999. Acoustic survey in fishing is one of the research methods that can detect the abundance of target species using acoustic detectors. For example, many pelagic fisheries are generally very scattered over a broad ocean and difficult to detect. Hence survey vessel with acoustic detector emits sound waves to estimate the density of plankton and fish shoal. Generally, the transducer is put under water, which is linked to an echo sounder in the vessel which records the shoals of fish as marks on a screen or paper trace. Then the density and number of marks are converted into biomass. Survey shot and haul stations have been based on acoustic survey data. The aim of an acoustic survey has been to determine the relative abundance of the target species. This information has been then used to determine catch rates and management advice for the following year. Acoustic surveys have been managed by the fisheries science section of the Marine Institute known as Fisheries Ecosystem Advisory Services who coordinated the annual surveys on board the research vessel Celtic Explorer. Data is considered a complete record of stations including only those stations between 1999 and 2009 as published on Irelands Marine Atlas.