Adaptation and further development of methods for hydroacoustic estimation of fish stocks
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.
Hydroacoustic monitoring methods allow direct determination of stock parameters and distribution patterns of (mainly) pelagic fish species. To utilise 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, for an implementation of an ecosystem approach, species-specific parameters have to be measured. Therefore, modern acoustic methods can be applied to obtain abundance and distribution estimates for different marine organisms and trophic levels, thus allowing an in-situ assessment of pelagic marine ecosystems.
Policy-makers in marine environmental as well as common fisheries policy; Fisheries scientists; interested public
The project is based on data that are collected during regularly conducted hydroacoustic surveys or on additional data that are collected during other surveys. Together with established post-processing methods for hydroacoustic data, further analyses on acoustic species identification, abiotic environmental parameters as well as acoustic/physical processes are conducted. By comparing multifrequency data from modern scientific echosounders with known acoustic parameters of different marine species, we are able to assess spatially highly resolving distribution patterns and habitat preferences of multiple fish species. Furthermore, we are able to estimate the precision of established trawl surveys in relation to actual distribution patterns of target species. By estimating hydroacoustically based abundance indices, we are able to provide and implement alternative survey concepts for important fish stocks. Additionally, we analyse influences of the physical environment on both distribution patterns as well as scattering/acoustic properties of fishes.
Hydroacoustic data are collected with modern scientific multifrequency echosounders.
1.2001 - 12.2020
Project status: ongoing