Comparison of marine mollusk assemblages between natural and artificial seashore in Taiwan

The natural coast of Taiwan is replaced by the artificial coast gradually, while disappearing at the extremely quick speed. The natural landscape is destroyed and the living beings perching in the natural coast face assaulting. The difference of mollusk assemblage between natural and artificial seashore in the eastern, western, northern and southern Taiwan were compared. Total of 39 families, 166 species, 8912 individuals of mollusk from different coast habitat, 135 species from nature seashore and 96 species from artificial seashore were recorded. There were 62 species found both in artificial and natural coast. The result indicates that there are higher diversity and evenness in natural coast. Littorinidae are dominant species and widely dispread both in nature and artificial coast. The microhabitat disappeared by artificial destruction result in lots of species disappear, the complexity of habitat decrease have influenced the community structure of mollusks directly. Feeding compositions are similar in both habitat, herbivorous mollusks are major populations, secondly carnivorous, thirdly filter feeding, lastly vermivorous habits. Littorinids, oysters and mussels become dominant species in the artificial coast. Moreover, carnivorous and worm’s feeding species reduce cause the energy level dropped, only the herbivorous or filter feeding guild remain in the lower levels.