Fishery. Photo: DTU Aqua

Fisheries management

DTU Aqua’s research into fisheries management develops methods, models and tools for estimating and evaluating the effects of management measures and regulations of fisheries. The results are used for advising national authorities and the EU.

Main themes within fisheries management systems

Which biological and economic effects can be expected for a fish stock and the affected fisheries and fleets, if fishing is regulated using quotas on landings or catches, by limiting the number of allowed days at sea, or by means of trawl mesh sizes or closed areas? DTU Aqua can perform a research-based evaluation to clarify such issues. 

The purpose of the evaluation is to optimize sustainable fishing and to minimize the impact of fishing on the ecosystem, including reducing fish discards.

Research into fisheries management has three main themes:

  • Models and tools for evaluating fisheries options and management
    DTU Aqua develops holistic models and tools which can contribute to increase the efficiency of fisheries management. The ecosystem and fisheries management models can vary from simple cases to complex issues involving several fish stocks, the affected ecosystem and several fishing fleets and are geographical and seasonal explicit. In addition, some models can link biological, climatic and socioeconomic conditions, to name but a few. Our work involves linking ecosystem simulation models or multi-species models with fisheries bio-economic simulation models, enabling us to compare different scenarios and options for fisheries management. Furthermore we link to other marine management within transport, energy, aquaculture and recreational use of the sea.

  • Models for estimating the impact of fishing on ecosystems
    DTU Aqua develops models for estimating the condition of fish stocks and key factors impacting them, including the impact of fishing on ecosystems. We evaluate and develop sustainable management options for e.g. mixed fisheries, i.e. fishing for several species and stocks simultaneously. We also develop models for evaluating closed fishing areas under spatial planning and various methods for minimizing fish discards. Moreover, we develop a tool for calculating the energy consumption and the CO2 emissions of individual vessels within different types of fishing. This will facilitate the development of management strategies that can help optimize the fuel consumption of the fishing industry. 

  • Indicators for the condition of and pressures on fish stocks and fisheries
    An important aspect of working with models is to develop the correct indicators for the conditions that need to be analysed. We develop
    • biological indicators for, e.g., the status of and impact on the affected fish stocks and the ecosystem, e.g. stock maximum sustainable yield (MSY)
    • bioeconomic indicators for, e.g., the activities and the actions of the fishermen. the efficiency of the fleets and the fishing economy.
    • indicatoros for energy efficiency of the fishery i terms of fuel consumption or CO2 emissions.
    • socioeconomic indicators for, e.g., the affected fishing fleets and local fishing communities. 

Why do we do research into fisheries management?

Fish and shellfish are a limited but renewable resource, which means that a sustainable exploitation of those is possible within the limits of productivity in nature. Therefore fisheries are subject to a large number of regulations to ensure that the productive potential of the fish and shellfish stocks is not jeopardized and to ensure economic and social sustainability of the fishery.

Within the EU, fisheries are, to a large extent, regulated by the EU’s common fisheries policy which is managed by the European Commission and the authorities in the individual member states. In Denmark, the Ministry of Food, Agriculture and Fisheries is the supreme authority in the area. 

In the management of the fisheries policy, a number of management measures and regulation methods are available to the authorities. These may, for example, include quotas for the amount of fish which the fishermen are allowed to land or catch, landing obligations and discard ban, regulations governing the properties and mesh sizes of fishing gears, closed fishing areas and marine reserves, limiting the number of days at sea for the fishing fleets and regulating fishing fleet sizes (activity and capacity regulations). Typically, several types of management are used at the same time, i.e. different management methods. 

But how do the different methods available to the fisheries management authorities work and how can we evaluate the effects of different methods? And how do they work when several methods are applied simultaneously? The research carried out by DTU Aqua helps to clarify this.

For example, is the best result achieved for a given fish stock if the management plan includes both quotas, a maximum number of fishing days and mesh size regulations, or should an area be completely closed for fishing or should fishing be banned for a period of time? What consequences will the composition of the management plan have for the fishing industry, and may fishers thus react? These are the type of issues on which the authorities need advice, and it is thus here that DTU Aqua carries out research. The research results in complex models and tools, which can be used in scenario evaluation for, e.g., simulating the expected effects of a management plan before implementing it – in the same way as a pilot flying a flight simulator before the first real flight. 

Fisheries management and regulation has become increasingly more complicated over the years and now also involves marine management in terms of other sectors, such as energy, aquaculture, transport and recreational use. Many fish stocks are, however, still exploited at a very high level in relation to the sustainability criteria. For that reason there is an urgent need for management research to continue the development for the benefit of both ecosystems and fisheries. 

What is the research used for?

The research conducted by DTU Aqua into fisheries management is, in particular, used in the consulting services we offer to fisheries management authorities: the EU and the Danish Ministry of Food, Agriculture and Fisheries. The consulting services help the authorities choose the best management options, measures, tools and systems and contribute to evaluating the existing management activities.  

In addition, we offer advisory and consulting services to international organisations such as the International Council for the Exploration of the Sea (ICES), the Helsinki Commission (HELCOM), EU Scientific and Technical Committee for Fishery (EU STECF), and Advisory Councils (ACs).  

The simulation models and evaluation tools produced by the fisheries management research make considerable use of biological data collected by DTU Aqua and international sister institutes, e.g. from the DTU Aqua’s research areas Marine Living Resources and Fisheries technology

We use monitoring data collected from commercial fisheries and during our own research surveys in an international collaboration. Economic fisheries and fleet data collected by the EU and the Danish Ministry of Food, Agriculture and Fisheries are also used in standard form in the models. The research in fisheries management thus helps ensure that the many data collected by DTU Aqua and other research institutes are used in practice and standardized to international formats and procedures.


Project websites

The DiscardLess project will help provide knowledge, tools and technologies to achieve the gradual elimination of discarding.  
Go to the project website

The EFIMAS project designed operational evaluation tools for fisheries management options.
Go to the project website

The IMAGE project examined the interplay between agriculture, fisheries, aquatic environmental qualities and economy in Baltic waters and developed a management evaluation tool which can address different eutrophication and climate scenarios and different agriculture and fisheries management options. 
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The BENTHIS project studies the impacts of fishing on benthic ecosystems and will provide the science base to assess the impact of current fishing practices.
Go to the project website

Fehmarn Belt
The project investigated fish stock and fisheries dynamics in relation to the marine environment as part of the impact assessment of the projection of the Fehmarn Belt Fixed Link between Denmark and Germany. 
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The SOCIOEC project promoted a scientific basis for ecosystem based and sustainable fisheries management and evaluated different options, e.g. bio-economic fisheries management modelling.
Go to the project website 

The VECTORS project examined the significant changes taking place in European seas and developed holistic ecosystem models of bio-geo-chemical dynamics, trophic interactions and anthropogenic impacts.
Go to the project website


J. Rasmus Nielsen
Ph. +45 21 31 49 69