Problems, policy and management of wetlands
It is now widely recognised that wetlands provide many important goods and services to human societies. Examples include drinking water, flood mitigation, water quality control, fish products and recreational and residential opportunities. The non-use values that society attributes to wetland species and ecosystems can also be significant (Turner et al., 1998a). Wetland ecosystems are, however, under stress from human activities, in particular changes in land use with concomitant habitat loss and fragmentation, resource extraction, drainage and reclamation, and pollution. Not surprisingly, wetlands are currently receiving considerable attention in environmental science and policy.
Wetlands all over the world are threatened, in spite of various international agreements and national policies to protect them. There are a number of fundamental reasons for this (see also Turner et al., 2000). Market failures exist because of the public good aspects of many wetlands and consequent lack of property rights for certain wetland goods and services. In addition, economic activities such as agriculture, industry and water abstraction trigger externalities for other stakeholders. These stakeholders include direct, indirect and even non-users of wetland goods and services. Next, there is a failure of information and a lack of understanding of the multitude of values associated with wetlands as a result of the complexity and ‘invisibility’ of spatial relationships between groundwater, surface water and wetland vegetation.