Hydroacoustic monitoring of fish stocks to determine stock parameters and distribution patterns
Hydroacoustic methods utilize sound waves to detect marine organisms. Modern echosounders can not only be used to determine stock parameters but also allow identification of habitat use, species composition and further parameters of marine ecosystems. These data are the basis for predictive models allowing estimating sustainable catch quotas.
Hydroacoustic monitoring methods allow direct determination of stock parameters and distribution patterns of (mainly) pelagic fish species. To utilize these parameters as a basis for predictive models estimating sustainable catch quantitites and to allow conclusions on distribution patterns and habitat use of different fish species, spatially highly resolving surveys of corresponding areas are required. Further, by concurrently measuring environmental parameters, estimates on distribution patterns and habitat preferences or habitat usage of different fish species can be made.
Policy-makers in marine environmental as well as common fisheries policy; Fisheries scientists; interested community
Within the framework of international surveys that are coordinated by the International Council for the Exploration of the Sea (ICES) we participate in surveys monitoring abundance indices of important fish stocks in the North Sea, Baltic Sea and Northeast Atlantic. On predefined hydroacoustic transects in the survey area data on echo distribution and total echo strength are collected, together with environmental parameters (temperature, salinity etc.). Based on total echo strenght/distribution, on species composition and corresponding length frequency distributions from targeted pelagic trawl hauls and based on backscattering characteristics of different fish species we are able to provide spatially highly resolved data on abundance, biomass and age structure of e.g. herring, sprat, blue whiting and redfish. These data are further used in internationally coordinated assessments of status and sustainable use of the corresponding stocks.
Hydroacoustic data are collected with modern scientific multifrequency echosounders.
How can hydroacoustic data be used to estimate abundances and distribution patterns of different marine species? What is the status of different (pelagic) fish stocks?
Estimates of biomass, abundance, age structure and distribution of pelagic fish stocks in the North Sea, Baltic Sea and North Atlantic
1.2001 - 12.2020
Project status: ongoing