Since the 1982 UN Convention on the Law of the Sea came into force, many countries have claimed their 200nm Exclusive Economic Zones (EEZs), and thus ownership of all resources within them. This extended jurisdiction by coastal states has wide-ranging economic impacts, and may provide various benefits through permitting access (usually restricted) by foreign vessels to their fish resources.

Developing countries face decisions as to what extent their own fishing industries should be developed, or to what extent they can benefit from licensing foreign fleets. If the decision is to permit foreign fishing, then secondary decisions are required to determine licence fee levels, budget allowance for compliance control (surveillance and enforcement) and legal frameworks such as fines for illegal fishing.


This project aimed to develop a suitable framework, based on modern mathematical bio-economics, in order to address these decisions faced by developing countries in a practical and rigorous way.

The approach was limited to theoretical study of the ways in which the marginal value of a nationally controlled resource (ie, the difference between income fishing inside a zone as opposed to fishing outside a zone) could be used, in conjunction with known parameters (for example, fish prices, catches, and surveillance costs), to estimate the optimum combination of income, surveillance costs and the legal penalties that might be applied to non-compliance.

The study used mathematical bio-economic analysis and optimal control theory to investigate the relationship between the potential benefits of foreign vessel licensing and the prerequisites to effective fisheries resource management, notably the cost of monitoring, control and surveillance.


This project has been extremely successful, highlighting the relationship between the level of licence fees that can be charged, the investment in surveillance and the legal penalties which lead to optimum revenue for coastal states licensing foreign fleets. Appropriate computer software has also been developed, in the form of a spreadsheet management game.

A review of different cases of access of foreign fleets provided data which enabled realistic mathematical models to be developed to assess optimal management decisions. It also highlighted that the data necessary to answer relevant questions are often available but not collected. A key result indicates that it is critically important to relate the fines for illegal fishing directly to the value or fishing power of the vessels concerned. This appears to be applicable whether the decision is taken to spend large or small amounts on surveillance.

The models developed enable fisheries managers to choose the optimal combination of levels of licence fees and investments in surveillance which will maximise the benefits to the coastal states, but also subject to necessary conservation restraints.

Follow-on project R5049CB applied these general models to a wide variety of different types of fisheries, in order to test and refine the methodology.