Fisheries Management

Main themes within the research area Fisheries Management

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.

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 advisory models can vary from simple cases of data limited stock assessment 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 end-to-end ecosystem simulation models or multi-species models with bio-geo-chemical climate models and 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 and methods 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, stocks and trophic levels simultaneously. We also develop models for evaluating closed fishing areas and their fisheries and ecosystem consequences under spatial planning and various methods for minimizing benthic impacts of fisheries or fish discards. Moreover, we have developed tools for calculating the energy consumption and the CO₂ emissions of individual vessels within different types of fishing and fleets. This facilitates the development of management strategies that can help understand and manage the contributions of the fishing industry to climate change. 
  
  
• 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 ecosystem functions and diversity, including benthic communities, e.g. stock maximum sustainable yield (MSY).
  • bioeconomic indicators for fleet activity and behavior, e.g. the decisions and actions of fishers, the efficiency of the fleets, and the sustainability of the fishing economy.
  • wider indicators of sustainability of the fishery in terms of fuel consumption or CO₂ emissions.
  • socioeconomic indicators for, e.g. the targeted fishing fleets and fishing communities. 
  • indicators to estimate the wider consequences of management interventions and appraise their socioecological consequences for the sector and more widely for other marine sectors and livelihoods.

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. However, as common goods, management interventions are required to ensure the sustainability of those exploitations. 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 the ecological, 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 competent 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 other marine sectors, 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, tools and methods, 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.  

Marine exploitation management has become more integrative over the past decade, so that fisheries management and regulation now also consider other marine sectors, such as energy, aquaculture, transport and recreational use. Spatial and temporal constraints imposed to fishery from other sectors by this integrative approach can limit access to certain areas for the fishery. It can also help researchers and managers to understand indirect effects on stocks from several sectors to better define sustainable yield considering broader pressures than just fishery, and also ensure the sustainability of traditionally fishing communities. Many fish stocks are, however, still exploited at a very high level in relation to the yield they can sustain. For that reason, there is still 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 provides the foundation for advice we provide to the EU and the Danish Ministry of Food, Agriculture and Fisheries. This advice 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 organizations 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), including broader stakeholder groups.  

The simulation models and evaluation methods produced by the fisheries management research make considerable use of biological data collected by DTU Aqua and international sister fisheries research 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 international collaborations. Economic fisheries and fleet data collected by the EU and the Danish Ministry of Food, Agriculture and Fisheries are also used as standard input for stock assessment and management models. Furthermore, we integrate stakeholder feedback information in our research projects. 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.