1. A Symposium on Water for Sustainable Inland Fisheries and Aquaculture was convened in conjunction with the Twentieth Session of the European Inland Fisheries Advisory Commission (EIFAC) in Praia do Carvoeiro, Portugal, from 23 to 26 June 1998. The Symposium was convened by Mr R. Müller (Switzerland) and chaired by Mr H. Ackefors (Sweden). The Symposium was attended by 68 participants from 23 countries.

Assessment of quantitative and qualitative characteristics of water resources

2. Ground and surface freshwater resources are finite but demand on them from various sectors and interests in society is increasing. Growing scarcity is therefore leading to competition between the various users including fisheries and is becoming a major issue in Europe and elsewhere. The intensification of use is also leading to greater pressure on water quality through pollution and eutrophication.

3. It was concluded that inland fisheries planners and administrators need to participate pro-actively in fora at all levels concerned with the allocation of water and management of living aquatic resources. Such participation is necessary to:

a) ensure that water is assigned for the maintenance of aquatic ecosystems and living organisms. Such allocation should include criteria for water use, including quantity, quality and timing which should be established on the basis of scientific evidence;

b) ensure that the aquaculture sector is not penalized by unrealistic requirements for effluent quality. It was recognized that for its part the aquaculture sector would need to be responsible in its approach to improving the quality of its discharges;

c) limit the potential damage resulting from introductions and transfers of exotic fish, and other animals and plants within the inland waters of Europe; and

d) promote awareness and knowledge of the social, economic and environmental significance of inland fisheries and aquaculture among decision-makers and stakeholders at all levels.

Water requirements of inland aquaculture systems

4. Aquaculture was established originally in regions where water resources were readily available but supplies are now becoming a limiting factor in some areas due to population increase, industrialization, environmental concerns and other factors. Several fish farms have had to convert from production to nature conservation or recreational areas. Other intensive fish farms are also having problems in the disposal of their effluents. Despite these difficulties, the need for fish as healthy food is increasing, and efforts are being made in many countries to increase the proportion of fish in the diet. However, given current circumstances, studies and trend analyses indicate that some conventional aquaculture systems need to evolve and adapt to changing social, economic and environmental conditions in many European countries.

5. Aquaculture must be accepted and legally recognized as a legitimate user of water.

6. The availability of freshwater resources for aquaculture production will continue to decrease in the future but new methods and production systems are available for the more efficient use and protection of those water resources that remain. While there is little need to introduce these into many countries at present, medium-and long-term planning of aquaculture development should consider their potential for the future. Research and development of new types of water efficient fish production systems should get priority in formulating R&D programmes.

7. The possibility of integrating aquaculture into irrigation systems should be considered as an

option for improved efficiency of water use. However a flexible approach is suggested which uses all types of habitat created by existing agronomic practices, the hydrological cycle and the features of the landscape. The principle of integration may also be applied on a wider scale, and more active collaboration among the various water users, planners and administrators is necessary. Collaboration between countries in which water shortage already exists and where such problems are anticipated in the future should also be promoted in order to exchange information and execute joint projects.

8. Fisheries scientists have an acceptable level of knowledge on the theoretical water quantity and quality requirements for fish for many aquatic ecosystems. Increasing pressures on water resources, coupled with a heightened public demand for truly sustainable development, means there are now key cross-disciplinary considerations related to the need to manage the environment as a whole. There is an increasing need for a better understanding of the different demands placed on the aquatic system and how these demands relate to one another. There is also a need for improved communication and acceptance of how the requirements of one user will modify and compromise those of another.

9. Water resources are generally under pressure under existing demand regimes. There is significant scope for reducing demand and managing impacts in order to comply with new environmental awareness. Given current levels of demand it will not always be possible to protect the environment fully, but the appraisal process must be carried out so as to balance priorities and apply mitigation measures.

10. Current knowledge is sufficient for technical interventions to mitigate continuing damage by other users or to rehabilitate impacted systems. Public incapacity to improve the aquatic system lies more in the sphere of policy making and allocation among different user groups. The new need is for political processes that will facilitate compromise by stakeholders and favour integrated resource management.

11. Fishery scientists should continue to build understanding of the impacts of hydrological change on fish communities. Robust environmental appraisal processes must be carried out to properly balance resource priorities, guide decisions on allocation and on any mitigation measures that may be necessary.