Tropical habitats such as coral reefs, sea grass meadows and mangrove forests are among the most productive and biodiverse ecosystems in the world. Worldwide millions of people depend on these ecosystems for their livelihoods and for coastal protection. In spite of this strong dependence, many ecosystems have degraded severely during the last four decades as a result of pollution, overharvesting, and coastal development. In many places degradation has reached such levels that coastal communities are on the brink of economic collapse due to catastrophic ecosystem failure.
Habitat degradation is a principal cause of the loss of biodiversity and ecosystem services, world-wide. The underlying causes are often complex, which makes natural ecosystem recovery a very slow process at best. In some cases natural recovery may not even be possible due to the existence of alternate stable ecosystem states or persistent pressures on the ecosystem. In such cases artificial intervention in terms of direct habitat enhancement may be the only option for (partial) recovery. Sometimes nature needs a helping hand to get started again.
Benefits of habitat enhancement
Active habitat enhancement can restore ecosystem services which not only result in reduced costs for society but also recovery of ecosystem productivity. For example, fish biomass production increases if the natural functions of coral reefs and mangroves are improved or if suitable artificial alternatives are provided. Other benefits may include a rise in income from tourists, improved coastal protection and resilience to sea level rise.
Habitat enhancement may entail a large range of seemingly unrelated measures (Fig. 1) ranging from the deployment of artificial habitat-like structures (eg. artificial reefs for coastal protection) to the use, farming, or seeding of bio-building species such as oysters, corals or mangroves.