BIOLOGICALY IMPACTS OF OIL POLLUTION : MANGROVES

Mangroves have traditionally provided plant product, fish and shellfish for coastal communities in the tropics. They also provide services such as coastal stabilization and food chain support for near-chore fisheries. This report provides information on the ecology and human use of mangroves, and on the fate and effects of oil. These topics, together with clean-up methods and rehabilitation, are discussed with reference to case history experience and results from field experiments.

Ecology of mangrove forests :

Mangroves are salt-tolerant species which grow in the tropics and some sub-tropical regions. They desalinate sea water by a filtration process. Mangrove roots typically grow in anaerobic sediment and receive oxygen through small pores on the aerial roots and trunks. Mangroves support many different biological communities, and can be one of the most productive ecosystems, supporting large populations of invertebrates, fish, birds and mammals.

Human use of mangroves:

Sustainable uses ;
The mangrove ecosystem produces both ‘goods’ (products) and ‘services’. Products include fuelwood, paper pulp, poles, railway sleepers, wood for furniture, roof thatching, bark for tannin, medicines, sugar, alcohol and dyes. Mangroves also provide fish and shellfish.
Services include :
- Protection of shorelines
- Trapping of water-borne pollutants
- Nursery and feeding grounds for fish, prawns, crabs and mollusks
- Nesting sites for birds; and
- Resources for tourism and recreation

Non-sustainable uses:
Non-sustainable uses lead to loss of the mangrove habitat, and associated losses of shoreline, organic matter and species. Mangrove forests are felled to make room for aquaculture, salt pans, rice fields, airport and road construction, port and industrial development, resettlement and village development.

Conservation:
Conservation objectives include:
- Maintenance of ‘reservoirs’ for