Online ISSN : 2186-8565
Print ISSN : 0911-9310
ISSN-L : 0911-9310
廣瀬 孝太郎後藤 敏一
ジャーナル オープンアクセス

2009 年 25 巻 p. 21-36


We investigated the recent diatom assemblages in 30 surface sediment samples from Osaka Bay, Japan, with the identified diatoms divided into five categories [halobious system ; Oligoeuryhaline Polyhalobous (OPH), Euryhaline Polyhalobous (EPH), Mesohalobous (MEH), Euryhaline Oligohalobous (EOH) and Stenohaline Oligohalobous (SOH)] based on their tolerance for salinity. The horizontal distribution pattern of each category suggested that the recent diatom distribution pattern of the bay is mainly controlled by the transportation of brackish/freshwater species from the mouth of the Yodo River through the river-water discharge into the bay. In other words, the distance from the river mouth controls the relative abundance of brackish/freshwater species at each site, which is a major part of the total floral composition and could be a useful paleoecological indicator for river-water discharge. The distribution pattern of Chaetoceros resting spores suggests they have potential as a paleoecological indicator for anthropogenic environmental degradation in exploited embayments. Taphonomic processes of recent diatoms are also discussed.

© 2009 日本珪藻学会
前の記事 次の記事