| Abstract | Shrimp fisheries and farming, difference of shrimp population in different
condition of mangroves were examined at Welu Estuary in Khlung District, Chantaburi
Province. In the estuary there was a large pristine mangrove area and abundant brackish
water animals especially penaeid shrimps, but the large areas of mangrove forests were
conve1ted into shrimp ponds, and then penaeid and other shrimp production were gradually
decreased in this area.
The small-scale fishers and shrimp farmers of Boh Sub-district were chosen for this
studied due to they got effect from decreased of shrimp stock in their fishery activities as
trammel net, shrimp-spear, and extensive shrimp farming along Krob river.
The species, size composition, and seasonal abundance of shrimps in four different
habitats, 1) Shrimp pond without mangrove fringe, 2) Shrimp pond with mangrove fringe,
3) River fringe of mangrove forest, 4) Mangrove creek, were studied in order to determine
the effect from changing of mangrove habitats to shrimp populations. The sampling was
performed in April, June and July 2006. Samples were collected three times at each habitat
in a month by plankton net in night time, and trammel net in day time. A total of 1,252
individuals belonging to four penaeid species (Penaeus merguiensis, P. indicus, Penaeus sp.,
and Metapenaeus sp.) and Sergestidae, Palaemonidae, Alpheidae, Mysidae and mantis
shrimp were collected. There was significant difference in mean catch among habitats. The
penaeid sluimps were found only habitats with mangrove forest, while two shrimp groups as
Sergestidae and Mysidae were found in all habitats. However, abundance of these two
sluimp groups was also higher in mangrove habitats than mangrove cleared habitats.
Information regarding fishing activities of small-scale fishers (i.e. trammel net fishers
and shrimp-spear fishers) and extensive slu·imp farmers, and perception and paiticipation of
mangrove and shrimp conservation were collected by interview and PRA. Shrimp production
from trammel net fishers was also estimated by sampling from fishery catch. Each fishery
was compared in terms of production and income between high and low production period.
The production and income of extensive shrimp farming were compared between shrimp
pond with mangrove fringe and slu·imp pond without mangrove fringe, which extensive
slu·imp pond with mangrove fringe showed higher productivity than pond without
mangroves.
For the perception and participation of small-scale fishers and slu·imp farmers to
conserve slu·imp stock and mangrove forest, there was few factors which encourage their
participation e.g. income, perception on affect of their livelihood from changing of slu·imp
stock. Therefore, though almost of small-scale fishers group and shrimp farmers group had
awareness in the necessary for participation on slu·imp stock and mangrove conservation
but only half of each group had experience in these participation.
The result of this study suggests that mangrove area could enhance the shrimp
stock, and these findings can be used to promote understanding of benefit of mangroves by
the small-scale fishers and slu·imp farmers, and develop conservation measure in which
slu·imp stock and mangrove conservations are compatible.
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