They allow :
- Flood regulation
- Maintenance of water quality and pollution control
- Development of social and economic activities (agriculture, extensive grazing, fisheries, leisure activities, etc.).
These habitats act as real biological reservoirs.
As well as being looked on as a resource, Mediterranean wetlands have long been considered hostile to people and over the centuries they have been "sanitised", drained and filled in. The area occupied by wetlands has decreased steadily. Currently, the majority of Mediterranean wetlands are endangered by hydraulic works, pollution, climatic change and the introduction of exotic plants and animals. It is estimated that over the course of the last fifty years or so, half the wetlands have been destroyed. For example, in the Mediterranean area:
- 86% of the main wetlands in France were degraded between 1930 and 1994
- 73% of the marshes in northern Greece have been drained since 1973
- 60% of the initial area of Mediterranean wetlands in Spain have disappeared
- 84% of the wetlands of the Medjerda Basin in Tunisia disappeared during the 20th century.
Only now with the realisation of how much of their natural functioning has been lost has the full extent of the economic, social and environmental importance of Mediterranean wetlands begun to be appreciated.
La Tour du Valat, together with other organisations, has instigated a number of initiatives favouring wetland conservation, including international treaties, the MedWet Initiative, support for national policies, the creation of protected areas, and programmes for management and restoration, training, education and awareness raising. The conservation of wetlands is no longer seen as an obstacle to development but rather as an essential measure by those working for sustainable development. The role of, and the need for, research organisations such as the Tour du Valat, which are able to lend their credibility and expertise when advising on the conservation and sustainable development of wetlands, is certain to increase.