the coast or estuaries and they are affected by the tide and flow
with a wide variety of environments throughout the tropical
and sub-tropical regions (Nybakken 1992; Aksornkoae 1993).
Mangrove plays an important role in the lifecycle of various
aquatic organisms such as fishes, shrimps and mollusks especially
for spawning, nursery and feeding grounds (Pramudji
2001). Mangrove as a feeding ground contributes to the habitat
complexity and diversity of the macrofauna associated in
mangrove ecosystem, while crustaceans and mollusks are the
dominant macrofauna in this ecosystem (Hutchings & Saenger
1987; Sasekumar 1974). The macrofauna diversity and abundance
may reflect biological indicators of changing habitat in
mangrove ecosystem (Macintosh et al 2002).
The past tsunami in late 2004 has destroyed and reduced the
mangrove ecosystem in Aceh coastal zone and it resulted in a
negative impact on mangrove biota for example Gastropods
and Bivalves. According to Dewiyanti (2005) Rhizopora apiculata,
R. stylosa and Avicennia marina were the dominant
species of mangrove pre tsunami in Ulee Lheue coastal, Banda
Aceh city. Furthermore, Dewiyanti (2005) reported that there
were 22 species of Gastropods and 17 species of Bivalves occurred
before tsunami in mangrove area of Ulee-Lheue where
the most dominant families were Cerithidae and Isognomonidae
for Gastropods and Bivalves, respectively.
The changes of mangrove forest from the stable vegetation pre
tsunami to the newly vegetations covered by sapling and seedling
certainly caused a serious impact to the biotic life in changing
of community structures in relation to abundance and diversity.
Most of Bivalves, not only were consumed by the local people,
but also were used as a commercial alternative livelihood of local
people to increase their income. Gastropods and Bivalves
are generally benthos organism and they are regularly used as
bio-indicators of aquatic healthy. Gastropods and Bivalves can
produce a billion of larvae in the form of meroplankton that sustains
the biotic population and they have a role in food chain.
The observation of Gastropods and Bivalves populations in
mangrove ecosystem is important to evaluate their condition
in the post tsunami rehabilitation program in Aceh where the
new communities have begun to form. Hence, the objective
of the present study was to assess the species composition of
Gastropods and Bivalves in mangrove rehabilitation area post
tsunami based on the different level of vegetation age.