Mangrove forests have declined significantly in
Southeast Asia over the past four decades. The main
reasons for mangrove loss and degradation have been
population pressure, wood extraction, conversion to
agriculture and salt production, tin mining, coastal
industrialization and urbanization, and conversion to
coastal aquaculture (Ong, 1995; Macintosh, 1996).
Shrimp farming in particular has had a major impact
on mangroves in several countries (Primavera, 1993).
In Thailand, for example, the mangrove forest area
declined from an estimated 367 900 Ha in 1961
to only 168 682 Ha in 1993, a decrease of 54%
(Khemnark, 1995). The specific causes of mangrove
destruction in Thailand up to 1986 (by area) were:
conversion to shrimp ponds (64%); coastal developments
(26%) other activities including salt ponds
(6%); and tin mining (3%) (Aksornkoae et al.,
1993).
Increasing awareness of the true value of mangrove
ecosystems has led to renewed efforts to protect and
restore them. Mangrove restoration or rehabilitation
has been initiated successfully in various parts of
*Corresponding author. E-mail: don.macintosh@biology.au.dk the world, including Thailand (Khemnark, 1995