| Title: | Implications of changes in the benthic environment and decline of macro-benthic communities in the inner part of Ariake Bay in relation to seasonal hypoxia |
| Authors: | Tsutsumi, Hiroaki Browse this author →KAKEN DB |
| Takamatsu, Atsushi Browse this author |
| Nagata, Sayaka Browse this author |
| Orita, Ryo Browse this author |
| Umehara, Akira Browse this author |
| Komorita, Tomohiro Browse this author |
| Shibanuma, Seiichiro Browse this author |
| Takahashi, Tohru Browse this author |
| Komatsu, Toshimitsu Browse this author |
| Montani, Shigeru Browse this author →KAKEN DB |
| Keywords: | Ariake Bay |
| halocline |
| red tide |
| stratification of the water |
| tidal currenｔ |
| Issue Date: | 2015 |
| Journal Title: | Plankton and Benthos Research |
| Volume: | 10 |
| Issue: | 4 |
| Start Page: | 187 |
| End Page: | 201 |
| Publisher DOI: | 10.3800/pbr.10.187 |
| Abstract: | In the inner part of Ariake Bay, located on the west coast of Kyushu, in western Japan, red tides have occurred with more frequency since the second half of the 1990s. Hypoxic waters have occurred during the summer months since the 2000s, despite the fact that nutrient loading from the land to the bay has not increased over the last five decades. We monitored water conditions at nine stations in the inner part of the bay, conducted benthic environmental surveys, and quantitative samplings of macro-benthic communities at the innermost four stations between 2002 and 2008. Each summer, the water was well-stratified due to the development of a halocline and a thermocline. The DO of the water below the pycnocline fell to hypoxic conditions. At the innermost three stations in the bay, the mud content and organic matter content of the sediment increased significantly, and the carbon stable isotope ratios of the organic matter contained in the sediment ranged between −21.3±0.5‰ and −20.7±0.5‰ of δ13C. These facts indicated that the organic matter was derived photosynthetically from marine phytoplankton. The increase in the mud content of the sediment indicates a deceleration in the tidal current. This may be a key event that induces a series of environmental changes and disturbances, including the stratification of the water, the more frequent occurrence of red tides, the progress of the organic enrichment of the sediment, and the occurrence of hypoxic water during the summer. |
| Rights: | © 2015 Plankton Society of Japan and Japanese Association of Benthology |
| Type: | article |
| URI: | http://hdl.handle.net/2115/67176 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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