Man meets mangrove

Moses Chege, intern at UNEP in Nairobi

There are eight species of mangrove trees along the Kenyan coast. Approximately 53,000 hectares of the mangrove forest are found in the Lamu area, along the northern coast, and the Vanga-Funzi area, near the Tanzanian boarder. The main threat to any ecosystem is man. As human pollution increases, man continues to put more stress on vital ecosystems in general and on mangroves, a species that takes a long time to regenerate, in particular.

Human threats to mangrove ecosystems can be roughly divided into two categories: consumptive and non-consumptive. A threat is consumptive when whole trees, or parts of them, are cut for products such as timber, fuel, or pulp. It is non-consumptive when forests are threatened by human activity other than the direct exploitation of the trees.

Various sectors, such as agriculture, fisheries, industry, tourism or construction, have a damaging impact on coastal ecosystems. Long-term effects may include loss of biodiversity and natural resources, which would impair future generations. In many countries, major cities and industries are located along the coast, causing increased environmental degradation through pollution, excessive water consumption, land misuse, beach erosion and inadequate waste disposal methods.

For example, the conversion of mangrove and sea grass areas into aquaculture ponds destroys critical ecosystems that nurture juvenile fish and filtrate sediments. Furthermore, illegal logging and mining cause soil erosion and contaminate rivers and seas. The harvesting of banned species and illegal fishing practices like blast fishing or the intrusion of commercial fishing vessels into municipal waters deprive local fishermen of food and income and deplete natural resources and biodiversity.

There are other threats to these fragile yet important ecosystems. A few examples are the conversion of mangrove forests to other land uses, the collection of non-wood products and oil pollution through extensive tanker transportation.
There is an urgent need to address the problems facing mangrove forests in Kenya and in the world. This will promote sustainable development and thus economic development for today’s and future generations. Action needs to begin at the individual level before communities and nations as a whole can take responsibility. ■

Photo: Viivi Erkkilä

References

FAO, The world’s mangroves 1980-2005. FAO forestry paper 153. Rome: Food and Agriculture Organization of the United Nations, 2007. Available at FAO.org.

UNEP, Eastern Africa Atlas of Coastal Resources: Kenya. Nairobi: United Nations Environmental Programme, 1998.

S.P. Godrej Marine Ecology Centre, “Mangrove Conservation by Soonabai Pirojsha Godrej Marine Ecology Centre.” Available at mangroves.godrej.com.

F. Hoogervorst, “East African Wildlife Society - Good News for Mangroves,” Swara Magazine 1996. Available at easternarc.org.