Multiple use of inland water ecosystems

Competing for resources

Fish stocks of various types of inland waters, such as lakes with their floodplains, reservoirs, rivers, wetlands and coastal lagoons are exploited for a range of fishery related purposes. The same waters are used for a number of human activities other than fisheries including power generation, agriculture, navigation, tourism, urban and industrial water supply and waste disposal. These compete with fisheries by modifying the structure of the environment and the quality and quantity of water. In so doing they threaten the sustainability of aquatic ecosystems and the fisheries that depend on them.

Many of these alternative demands on water are judged by society to be of greater value than fisheries and therefore are assigned a higher priority in reaching decisions as to the allocation of water. In lakes, human and natural processes in tributaries and the lake itself impact on the quality and quantity of fish present. In rivers the state of the environment reflects the accumulation of upstream processes. Current approaches to management are frequently piecemeal, based on national or administrative frontiers; broader mechanisms are needed to overcome these limitations.

Fisheries scientists know 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 that 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.

Demand and supply

Given current levels of demand it will not always be possible to protect the environment fully, but 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. Current knowledge is sufficient for technical interventions to mitigate continuing damage by other users or to rehabilitate impacted ecosystems. Public capacity 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 involvement by all stakeholders and favour integrated resource management.

It is important that concepts of social and economic value and use are developed for inland fisheries so that fisheries interests can be properly represented in the allocation debate and development plans. Collaboration with local stakeholders and with other groups expressing public concern for the environment should be sought in order to influence planners and politicians. The proper representation of fisheries requires improved long-term trend analysis, and assessment of economic and social value of fisheries and associated externalities. Lake and river basin authorities, charged with the conservation and management of the resources of such basins, and where the prime objectives of such authorities is other than fisheries, should explicitly have included in their remit protection of aquatic resources for their biodiversity andbiodiversity and fisheries.

Developing responsible strategies

Strategic planning for the inland fisheries and aquaculture sectors must take part in the wider discussions and decisions concerning future water resources allocation and water quality management. Those responsible for decisions on ground and surface water allocation and management at all administrative and technical levels must make adequate water available for maintenance of quality and timing of stream flows, water quality, and where deemed necessary for rehabilitation and improvement to maintain and enhance valuable recreational, commercial and subsistence fisheries.