Abstract
This study unveiled the distribution pattern of total carbon (TC), total nitrogen (TN), and total phosphorus (TP) in the surface sediment of Lake Ogawara. Furthermore, zoobenthos community structure was compared between sites with different TP level. Our results suggested: (1) The distribution patterns of TC, TN, and TP were different spatially: TN was enriched in the center part of the lake where water depth is deep, while TP was enriched in the southern part of the lake where the major inflowing rivers are inpouring. (2) Dominant species of zoobenthos was different between northern-center, and southern part of the lake: Corbicula japonica was dominant in the northern-center part, while Tubificidae sp. was dominant in the southern part. (3) Distribution of particle size and TN in each size fraction was different at the three sites, which was attributed to the material loading from the inflowing rivers. In summary, it is suggested that the sediment environment and zoobenthos community structure in the Lake Ogawara is influenced by the loading of substances responsible for eutrophication from the inflowing rivers.
