Institute of

SF Sea Fisheries

Project

Hydroacoustics - Methods, Applications, Development

Lead Institute SF Institute of Sea Fisheries

Unlike many other fish species, such as herring, sprat or cod, mackerel do not have a swim bladder and are therefore very difficult to record or quantify using classic hydroacoustic methods. However, with modern multi-frequency echo sounders and corresponding evaluation procedures, this is now possible and can thus be used for an alternative recording of stock parameters.

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.

Background and Objective

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.

Target Group

Policy-makers in marine environmental as well as common fisheries policy; Fisheries scientists; interested public

Approach

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.

Data and Methods

Hydroacoustic data are collected with modern scientific multifrequency echosounders.

Our Research Questions

How can hydroacoustic data contribute to an ecosystem survey?
How can we utilise hydroacoustic data to evaluate and expand established scientific surveys?

Preliminary Results

Publications in international, peer-reviewed journals
Presentations and working group documents in different ICES working groups (e.g. WGFAST, WGTC etc.)

Links and Downloads

International Council for the Exploration of the Sea (ICES)

Thünen-Contact

Dr. Matthias Schaber

Telephone

+49 471 94460 452

matthias.schaber@thuenen.de

SF Institute of Sea Fisheries

Involved Thünen-Partners

Gastauer, Sven SF Institute of Sea Fisheries

Duration

1.2001 - 12.2027

More Information

Project status: ongoing

Fotostrecke (ziehen Sie das Bild zur Seite)

Echogramm aus dem Kattegat — Verschiedene Meerestiere liefern unterschiedliche Echosignaturen, vor allem, wenn man gleichzeitig Echogramme von Echolotschwingern verschiedener Frequenzen analysiert. Man kann sich hierbei die sogenannte „Frequency response“, also eine typische Echosignatur bei bestimmten Frequenzen, zunutze machen. In der rechten Bildhälfte (120 kHz-Echogramm) sieht man einen dichten Schwarm ab ca. 70 m Tiefe in einer Senke. Das sind Mysidaceen (Schwebgarnelen). Auf beiden Echogrammen (links und rechts) sieht man im Bereich vor der Senke einzelne Signale, die von großen Heringen und auch von Seelachsen stammen. Auf dem linken Echogramm (38 kHz) ist der Mysidaceenschwarm aufgrund seiner Frequency Response nicht sichtbar. Dafür erkennt man Signale einzelner Fische, die im Bereich des Schwebgarnelenschwarms schwimmen. Dies sind räuberische Seelachse (Pollachius virens), die sich von den Mysidaceen ernähren.

Multifrequenz-Identifikation der Atlantischen Makrele (Scomber scombrus) — Zur akustischen Identifizierung von Makrelen macht man sich deren „Frequency Response“ bei verschiedenen Frequenzen zunutze. Makrelen haben bei verschiedenen Arbeitsfrequenzen der Echolote verschieden starke, aber typische Echosignaturen. Mittels aufeinander aufbauender Algorithmen, die auf der besagten Frequency Response basieren, können selbst in gemischten Schwärmen (1. und 2. Bild v.l.) „Makrelenkandidaten“ (2. Bild v.r.) identifiziert werden und zur Biomasse- und Abundanzberechnung aus den Echodaten isoliert werden (rechtes Bild).

Publications

0
Van Dijk TAGP, Roche M, Lurton X, Fezzani R, Simmons SM, Gastauer S, Fietzek P, Mesdag C, Berger L, Klein Breteler M, Parsons DR (2024) Bottom and suspended sediment backscatter measurements in a flume - Towards quantitative bed and water column properties. J Mar Sci Eng 12(4):609, DOI:10.3390/jmse12040609
https://literatur.thuenen.de/digbib_extern/dn068519.pdf
1
Jech M, Schaber M, Gastauer S, Alegria N, Algroy T, Andersen LN, Anderson C, Annasawmy AP, Arendt C, Ariza A, Barbin L, Berger L, Boyra G, Brehmer P, Bristow M, Calise L, Carlsen A, Cermak J, Chawarski J, Chu D, et al (2022) Working Group of Fisheries Acoustics, Science and Technology (WGFAST). Copenhagen: ICES, 93 p, ICES Sci Rep 4(54), DOI:10.17895/ices.pub.20178464
https://literatur.thuenen.de/digbib_extern/dn065841.pdf
2
Jech M, Ariza A, De Robertis A, Rezvanifar A, Lavery AC, Lebourges-Dhaussy A, Sepulveda A, Bertrand A, Blanluet A, Scoulding B, Berges B, Bárðarson B, Robinson C, Wall C, Anderson C, Taylor C, O'Donnel C, Grados D, Copland D, Schaber M, et al (2020) Working Group on Fisheries Acoustics, Science and Technology (WGFAST). Copenhagen: ICES, 18 p, ICES Sci Rep 2(70), DOI:10.17895/ices.pub.7444
3
Gröhsler T, Schaber M (2014) Annex 6: Cruise reports from other acoustic surveys in the area : Annex 6a: Western Baltic acoustic survey ; Survey report for FRV "Solea" ; German Acoustic Autumn Survey (GERAS), 30 September 2013 - 19 October 2013. In: Report of the Working Group of International Pelagic Surveys (WGIPS) ; 20-24 January 2014. Copenhagen: ICES, pp 224-251
4
Gröhsler T, Schaber M (2014) Survey Report for FRV "Solea" German Acoustic Autumn Survey (GERAS) 30 September 2013 - 19 October 2013. In: Report of the Baltic International Fish Survey Working Group (WGBIFS) : 24-28 March 2014 ; Gdynia, Poland. Copenhagen: ICES, pp 250-258
5
Planque B, Kristinsson K, Astakhov A, Bernreuther M, Bethke E, Drevetnyak K, Nedreaas K, Reinert J, Rolskiy A, Sigurdsson T, Stransky C (2013) Monitoring beaked redfish (Sebastes mentella) in the North Atlantic, current challenges and future prospects. Aquatic Liv Res 26(4):293-306, doi:10.1051/alr/2013062
6
Schaber M, Gröhsler T (2013) Survey Report for FRV "Solea" 2-21 October 2012. In: Report of the Baltic International Fish Survey Working Group (WGBIFS) : Annex 8: Cruise reports of acoustic surveys BASS and BIAS in 2012. Copenhagen: ICES, pp 266-289
7
Bethke E, Götze E, Planque B (2010) Estimation of the catchability of redfish and blue whiting for survey trawls in the Norwegian Sea. J Appl Ichthyol 26:47-53, DOI:10.1111/j.1439-0426.2010.01446.x

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