Sustainable Management - Seagrass Beds

Seagrass beds have an immense ecological and economical importance to tropical coastal areas. They are the base and for a large number of commercial fish and shellfish, at the same time as they physically stabilise the coastal areas, serve as sediment filters and harbour some of the major biological sand producers. However, presently little is known about the distribution and status of east African seagrass beds.

In the present situation in the east African region, fast developments are taking place. While in many ways beneficial to the coastal population, developments in e.g. the tourism industry and seaweed cultivation might have detrimental effects on the seagrass beds, possibly leading to extensive coastal degradation thereby, hitting back on the newly developed industries. The project "Sustainable Management and Valuation of Seagrass Ecosystems in the Western Indian Ocean Region" aimed to, in a regional cooperation network, assess the damage that has already taken place and by using modern ecological, physiological and economical tools, and estimated possible future impacts. Specific objectives of the project were to:

i) assess seagrass structural importance and ecosystem function. Here the following aspects were covered: seagrass production; biomass; nutrients; seagrass mapping, a monitoring program through seagrass mapping, to be able to follow changes in the seagrass meadows; as well as Halimeda studies and seaweed studies.

ii) assess vulnerability of seagrasses to stresses. Here the following aspects were covered: eutrophication (both in seagrasses and macroalga); siltation and toxicity studies.

iii) evaluate seagrass ecosystems. The following aspects were covered: ecological-economics in general; fin-fish and invertebrate food resources; productivity; their role in hindering beach erosion; as nursing and recruitment areas for fishes; the couplings between the different ecosystems within