Important legal notice
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Fisheries and Aquaculture
Fisheries and Aquaculture - Towards sustainable development of fishing and aquaculture activities
“NECESSITY will help stabilise and maintain the long-term viability of small cetacean populations by reducing, if not eliminating, the number currently caught and drowned in trawls.”

The problem

The long-term sustainability of some European fisheries is called into question due to the high by-catch. In many nephrops fisheries, the non-target catch is dominated by species subject to total allowable catch (TAC) and quota management controls, such as cod and haddock. Netted adults may be in excess of the permitted quota or there may be an abundance of juveniles – all of whom must be discarded but few survive. In other fisheries, porpoises and dolphins are caught and drown in numbers that may exceed the population regeneration rate.

NECESSITY  Modified fishing gear and practices to reduce by-catch in trawl fisheries


NECESSITY will develop ways of modifying trawls to enable by-catch species to escape from the trawl unharmed. The project will:

  • Study the behavioural characteristics that make small cetaceans (i.e. porpoises and dolphins), and certain fish species or age groups vulnerable to capture in trawl fisheries
  • Develop alternative fishing strategies, or fishing gear modifications, to reduce the by-catch in trawl fisheries
  • Consider the biological and socio-economic ramifications of modifying the fishing gear and practices
  • Transfer the information gathered to other fisheries subject to similar concerns

Contribution to policy development:

  • By reducing by-catch, NECESSITY will help the EU meet its commitments under the Common Fisheries Policy “to protect and conserve available and accessible living marine aquatic resources”
  • By reducing by-catch of cetaceans, NECESSITY will support the EU Council Regulation requiring Member States to take steps to ensure that incidental capture does not have a negative impact on cetacean species
  • The socio-economic aspects of the project will help “provide for rational and responsible exploitation, on a sustainable basis”
  • It will increase understanding of the consequences of adopting or varying particular fishery management measures

Project deliverables

  • Design and tests of fishing gear and cetacean exclusion devices – December 2004
  • Development of cost-benefit analysis (CBA) methods and models – September 2005
  • Modified fishing gear selectivity trials – December 2006
  • Sea trials of acoustic deterrents – June 2006
  • Assessment of cetacean behaviour and reactions to deterrents – June 2006


  • Project website launch (updated monthly) – October 2004
  • Final project reports submitted for peer review – May 2007

Technical information

Project acronym: NECESSITY
Project’s official full title: NEphrops and CEtacean Species Selection Information and TechnologY
Research priority: Modernisation and sustainability of fisheries, including aquaculture-based production systems
Specific webpage: Details not yet available
Proposal/contract no: 501605
Start date: 1/3/2004
Kick off meeting: March 2004
Completion date: 1/5/2007
European Commission scientific officer: Tore Jakobsen (

Name: Netherlands Institute for Fisheries Research
Abbreviated Name: RIVO
Address: Haringkade 1, 1976 CP Ijmuiden, Postbus 68, 1970 AB Ijmuiden
Country: The Netherlands
Tel: +31 (0) 113 672300
Fax: +31(0) 113 573477


Name: Cen­tre for En­­vi­­ronment, Fis­he­ries and Aqua­­­culture Science
Abbreviated Name: CEFAS
Country: UK

Name: Fisheries Research Services
Abbreviated Name: FRS
Country: UK

Name: University of St Andrews
Abbreviated Name: USTAN
Country: UK

Name: Sea Fish Industry Authority
Abbreviated Name: Seafish
Country: UK

Name: Institut Français de Recher­che pour l’Ex­ploi­tation de la Mer
Abbreviated Name: IFREMER
Country: France

Name: Centre de Recherche sur les Mammifères Marins
Abbreviated Name: ULR/CRMM
Country: France

Name: Finnish Game and Fisheries Research Institute
Abbreviated Name: FGFRI
Country: Finland

Name: Danish Institute for Fisheries Research
Abbreviated Name: DIFRES
Country: Denmark

Name: ConStat
Abbreviated Name: ConStat
Country: Denmark

Name: Danish Re­search Institute of Food Economics
Abbreviated Name: FOI
Country: Denmark

Name: Institute of Marine Research
Abbreviated Name: IMR-No
Country: Norway

Name: Institute of Marine Re­search, Natio­nal Board of Fisheries, Sweden
Abbreviated Name: IMR-Se
Country: Sweden

Name: An Bord Iascaigh Mhara
Abbreviated Name: BIM
Country: Ireland

Name: University College Cork
Abbreviated Name: UCC
Country: Ireland

Name: Agricultural Research Centre – Sea Fisheries Department
Abbreviated Name: CLO-DvZ
Country: Belgium

Name: Instituto Nacional de Investigação Agária e das pescas
Abbreviated Name: INIAP-IPIMAR
Country: Portugal

Name: Instituto de Ciencias del Mar
Abbreviated Name: ICM
Country: Spain

Name: Instituto Tecnologico Pesquero y Alimentario
Abbreviated Name: AZTI
Country: Spain

Name: Istituto di Scienze Marine - Consiglio Nazionale delle Ricerche
Abbreviated Name: ISMAR-CNR
Country: Italy

Name: National Centre for Marine Research
Abbreviated Name: NCMR
Country: Greece

Name: Institute of Marine Bio­logy of Crete
Abbreviated name: IMBC
Country: Greece

Name: Ege University, Fisheries Faculty
Abbreviated Name: EUFF
Country: Turkey