Fisheries research surveys: Monitoring of fish communities

Project

Unterwegs in der Bornholmsee zum Dorsche messen (c) Thuenen-Institut
Unterwegs in der Bornholmsee zum Dorsche messen (© Thuenen-Institut)

DCF (Data Collection Framework): Monitoring of cod, herring, sprat and flatfish stocks in the western Baltic Sea in the frame of internationally coordinated research cruises to estimate independent abundance indices.

Eine Seefahrt, die ist lustig… A research vessel cruise is mainly hard work onboard at sea, according to a fixed station grid and a tight schedule, under almost any weather condition. Expertise, routine and endurance are in demand.

Background and Objective

In former times, each country conducted fisheries-independent surveys in its national waters using national standards. Fish stocks, however, do not stick to national sea boundaries. To ensure maximum comparability between national survey data, these research surveys are internationally standardized since 2000. Thus, every year large areas of the Baltic Sea are monitored simultaneously by fisheries biologist from different countries using standard procedures.

The survey results are analyzed nationally and uploaded into the data base DATRAS of the International Council for the Exploration of the Sea (ICES). The data are used for estimation of fisheries-independent stock indices, determination of year-class strength and fishing mortality. These data are used in models to estimate stock status, together with the data collected from the fisheries.

Approach

On fisheries-independent research cruises, the catch procedure, the workup of the catch and data analysis followed precisely defined standards, which differ according to the aim of the cruise. These standards are documented in so-called survey manuals. Each research cruise has a scientific cruise leader. Technicians and research assistants have a central role in the workup of the catches on board.

Preliminary Results

We conduct the following important fisheries-indepedent research sruveys: the „Baltic International Trawl Survey“ (BITS) in February and October/November targeting demersal species, as well as the „Baltic International Acoustic Survey“ (BIAS) in May/June, and the „Baltic Acoustic Sprat Survey“ (BASS) in October targeting the pelagic species herring and sprat. The „Rügen Herring Larvae Survey“ (RHLS) in the Greifswalder Bodden provides estimates on year class strength at the level of recently hatched larvae.

Based on the research surveys we regularly determine important indices to assess the year class strength of certain fish stocks and estimate the fishing mortality. These are essential input parameters in the population models we use to estimate stock size and derive a reliable catch advice.

Thünen-Contact


Involved Thünen-Partners


Duration

Permanent task 1.2001 - 12.2018

More Information

Projekt type:
Project status: ongoing

Publications

hits: 18

  1. 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
  2. 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
  3. Krumme U, Gröhsler T (2013) Analysis of the questionaires concerning the issue of species misreporting in the mixed pelagic fisheries in the Baltic Sea (sprat-herring mix). In: Report of the Benchmark Workshop on Baltic Multispecies Assessments (WKBALT): 4-8 February 2013. Copenhagen: ICES, pp 266-276
  4. Oeberst R, Gröhsler T, Schaber M, Larson N (2013) Applicability of the Separation Function (SF) in 2011 and 2012. In: Report of the Baltic International Fish Survey Working Group (WGBIFS) : 20-25 March 2013. Copenhagen: ICES, pp 399-405
  5. Oeberst R, Gröhsler T, Schaber M (2013) Applicability of the Stock Separation Function (SF) on the first period of GERAS in 1994-2004. Working Document WKPELA2. Benchmark Workshop on on Pelagic Stocks (WKPELA): 4-8 February 2013. Copenhagen: ICES, 4 p
  6. Gröhsler T (2013) Assessment input database. In: Report of the Benchmark Workshop on Pelagic Stocks (WKPELA): 4-8 February 2013. Copenhagen: ICES, pp 417-437
  7. Oeberst R, Gröhsler T (2013) Comparison of stock indices based on GERAS estimated with the standard procedure and by the new proposed method : Working document Baltic International Fish Survey Working Group (WGBIFS) 20-25 March 2013. Copenhagen: ICES, 9 p
  8. Gröhsler T (2013) German herring and sprat fisheries & stock assessment data in the Baltic Sea in 2012. In: Report of the Baltic Fisheries Assessment Working Group (WGBFAS): 10-17 April 2013; Working Document 2. Copenhagen: ICES, pp 735-761
  9. Gröhsler T (2013) German herring fisheries & stock assessment data in the Western Baltic in 2012. In: Report of the Herring Assessment Working Group (HAWG) . Copenhagen: ICES, pp 806-818
  10. Gröhsler T, Oeberst R, Schaber M (2013) Implementation of the Stock Separation Function (SF) on German commercial landings. In: Report of the Benchmark Workshop on Pelagic Stocks (WKPELA): 4-8 February 2013. Copenhagen: ICES, pp 379-386
  11. Gröhsler T, Oeberst R, Schaber M (2013) Implementation of the Stock Separation Function (SF) within GERAS in 2005-2011. Working Document WKPELA 1. Benchmark Workshop on on Pelagic Stocks (WKPELA): 4-8 February 2013. Copenhagen: ICES, 6 p
  12. Oeberst R, Gröhsler T, Schaber M (2013) Investigations on quality of Stock Separation Function (SF). Working Document WKPELA4. Benchmark Workshop on on Pelagic Stocks (WKPELA): 4-8 February 2013. Copenhagen: ICES, 22 p
  13. Bartolino V, Gröhsler T, Vitale F, Krischansson B, Johansson M (2013) Maturity at age in the WBSSH herring : motivation of the study and background. In: Report of the Benchmark Workshop on Pelagic Stocks (WKPELA): 4-8 February 2013. Copenhagen: ICES, pp 470-475
  14. Krumme U, Gröhsler T (2013) Sprat (BS)/Central Baltic Herring (CBH): Analysis of the questionnaires concerning the issue of species misreportning in the mixed pelagic fisheries in the Baltic Sea (sprat-herring mix). In: Report of the Benchmark Workshop on Baltic Multispecies Assessments (WKBALT): 4-8 February 2013. Copenhagen: ICES, pp 266-276
  15. 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
  16. Oeberst R, Velasco A, Mieske B (2012) Measuring the international standard trawl for Baltic demersal surveys (TV3-520 Meshes) : working paper Working group of Baltic International Fish Survey, 26 – 30 March 2012. Copenhagen: ICES, 4 p
  17. Velasco A, Oeberst R (2012) Ungewöhnliche Gewichtsabnahme von Dorsch im 2. Jahresquartal im Bornholm Becken (ICES-Gebiet 25) und der Arkonasee (ICES-Gebiet 24). Inf Fischereiforsch 59:19-23, DOI:10.3220/Infn59_19-23_2012
    pdf document (limited accessibility) 255 kb
  18. Velasco A (2010) Bericht über die 629. Reise des FFS "Solea" vom 28.10. bis zum 19.11.2010. 8 p

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