The use of molluscan fauna as model Taxon for the Ecological classification of river estuaries
The use of molluscan fauna as model Taxon for the Ecological classification of river estuaries
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DOI：
10.3390/w9050356
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发表时间：
2017-05
期刊：
影响因子：
3.4
通讯作者：
Rei Itsukushima;Kai Morita;Y. Shimatani
中科院分区：
文献类型：
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作者：
Rei Itsukushima;Kai Morita;Y. Shimatani
河口是重要的水环境，其水质、河床物质和微地形在纵向和横向上具有较大的环境梯度。河口的地理或栖息地因潮汐、波浪和河流的能量而异，因此，栖息在河口的生物群因河口类型而异。有鉴于此，为了有效地保护河口，有必要根据河口类型的客观数据，了解潜在的栖息地和生物区系。因此，本研究的目的是分类河流河口的软体动物区系和物理指标，揭示软体动物区系和物理环境之间的关系。物理指标分类结果表明，河口湾可分为波能主导型河口湾、潮能主导型河口湾和低潮波能主导型河口湾3种类型。这一分类结果与软体动物区系的分类结果基本一致。因此，软体动物区系是非常有用的变量，代表河口环境。从软体动物区系与自然环境的比较来看，有些河流虽然具有相似的自然环境，但在软体动物区系的分类中却没有被归入同一组。其中一些河流的软体动物区系偏离预期，经历了通道改造，预计这将导致这一动物群的转变。这些结果表明，这种方法可以用来确定已被人类活动退化的河流。
River estuaries are important aquatic environments characterized by large environmental gradients in their water quality, riverbed material, and microtopography in the longitudinal and transverse directions. The geography or habitats in river estuaries differ depending on the energy from the tide, waves, and river; therefore, the biota inhabiting river estuaries vary depending on the river estuary type. In view of this, for effective conservation in river estuaries, there is a need for information about potential habitats and biota based on objective data about the river estuary type. The objective of this study thus was to classify river estuaries by their molluscan fauna and physical indicators to reveal the relationship between molluscan fauna and the physical environment. The classification results using physical indicators indicated three types of river estuaries (wave energy-dominated group, tide energy-dominated group, and low tide and wave energy group). This classification result was similar to the classification of molluscan fauna. Therefore, it was suggested that molluscan fauna is extremely useful as a variable representing the river estuary environment. From the comparison between molluscan fauna and the physical environment, some rivers were not classified into the same group in the classification of molluscan fauna, despite them having similar physical environments. Some of these rivers with a molluscan fauna that diverged from expectations had undergone channel modification, which is expected to have caused a shift in this fauna group. These results suggest that this approach could be used to identify rivers that have been degraded by human activities.