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maintaining high productivity as outlined previously. However, the mangroves are also very important as mud stabilizers. As the pioneers grow out onto the mud, the band of vegetation becomes broader and the rear becomes drier. Eventually new land is created, which can be used for agricultural purposes. They also play a role as an important protective barrier against destructive storm waves, thus reducing the risk of flooding.
Man's impact on the mangrove
The most significant impact by man has been the drainage and reclamation of the mangroves to provide sites for settlement and agriculture. This century alone about 1700 hectares of mangroves have been converted into deep fish ponds and vegetable growing areas and many of these, more recently, have been converted into container storage facilities and other industrial purposes. Many of Hong Kong's mangrove stands have already been totally destroyed; Mai Po's mangroves still survive to give an impression of what Deep Bay, indeed much of Hong Kong's shoreline would have looked like because they have been protected since 1976 as a Site of Special Scientific Interest. The effects of deep fish pond development, vegetable gardening, industrial usage and new town development can all now be seen in the Deep Bay area.
The likelihood of further major reclamation of Deep Bay for urban expansion poses new threats to the ecology of this mangrove area and to the life which it supports (Irving & Morton, 1988).
However, at present, the biggest threat is pollution. The many streams and rivers that drain into Deep Bay carry an enormous load of agricultural, domestic and industrial waste. Increasing pollution loads have already been reflected in a changed use of the ponds in recent years. A marked decrease in shrimp harvest has led to the conversion of some gei wais and mangrove areas to freshwater ponds to protect them from marine pollution. If this trend continues, then extreme changes will result as more and more of the mangrove areas are turned into deep ponds and, as pollution has a greater effect on mudflat productivity, the whole area will eventually lose the ecological value which it now has as a multifaceted series of habitats supporting an enormous variety of flora and fauna. In particular, it will cease to be a
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maintaining high productivity as outlined previously. However, the mangroves are also very important as mud stabilizers. As the pioneers grow out onto the mud, the band of vegetation becomes broader and the rear becomes drier Eventually new land is created, which can be used for agricultural purposes. They also play a role as an important protective barrier against destructive storm waves, thus reducing the risk of flooding.
Man's impact on the mangrove
The most significant impact by man has been the drainage and reclamation of the mangroves to provide sites for settlement and agriculture This century alone about 1700 hectares of mangroves have been converted into deep fish ponds and vegetable growing areas and many of these, more recently, have been converted into container storage facilities and other industrial purposes. Many of Hong Kong's mangrove stands have already been totally destroyed; Mai Po's mangroves still survive to give an impression of what Deep Bay indeed much of Hong Kong's shoreline would have looked like because they have been protected since 1976 as a Site of Special Scientific Interest. The effects of deep fish pond development, vegetable gardening, industrial usage and new town development can all now be seen in the Deep Bay area.
The likelihood of further major reclamation of Deep Bay for urban expansion poses new threats to the cology of this mangrove area and to the life which it supports (Irving & Morton, 1988).
However, at present, the biggest threat is pollution. The many streams and rivers that drain into Deep Bay carry an enormous load of agricultural, domestic and industrial waste. Increasing pollution loads have already been reflected in a changed use of the ponds in recent years. A marked decrease in shrimp harvest has led to the conversion of some gei wais and mangrove areas to freshwater ponds to protect them from marine pollution. If this trend continues, then extreme changes will result as more and more of the mangrove areas are turned into deep ponds and, as pollution has a greater effect on mudflat productivity, the whole area will eventualy lose the ecological value which it now has as a multifaceted series of habitats supporting an enormous variety of flora and fauna. In particular, it will cease to be a
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