[A-CG43] 沿岸海洋生態系──２．サンゴ礁・藻場・マングローブ

[ACG43-P08] Characteristics of water quality in the river of the Philippines

*森本 直子¹、梅澤 有²、渡邉 敦³、マックグローン マリア⁴、フェレラ チャリッサ⁴、レジーノ・モンポンバウナ ジェネビーブ⁴、宮島 利宏¹ (1.東京大学大気海洋研究所 海洋化学部門、2.東京農工大学大学院 農学府、3.東京工業大学 環境・社会理工学院、4.フィリピン大学 海洋研究所)

キーワード：河川流入、陸源負荷、C,N,O,H同位体比、熱帯沿岸域

Terrestrial inputs is one of the key factors for degradation of coastal habitats these days, whose effect is greatly increasing by development of its drainage basin through e.g. change of the land use and population increase, causing local eutrophication and suspendation. Coastal areas are also threatened by various human activities, such as mariculture, and environmental changes caused by global warming. However, those water qualities of rivers are not well investigated especially in coral triangle areas, which are the center of marine biodiversity. In this study, samples were collected both in the wet and dry seasons along the rivers to compare the site-specific characteristics of Luzon, Panay, Negros, Mindoro, and Mindanao islands of the Philippines. We analyzed nutrients, dissolved/particulated inorganic/organic carbon and nitrogen, isotopic composition such as δD/δ¹⁸O-H₂O, δ¹⁵N/δ¹⁸O-NO₃, δ¹³C-DIC and δ¹³C/δ¹⁵N-POM. Especially dissolved parameters seem to be well reflected local characteristics. Relationships between each component also allow us to estimate carbon and nitrogen dynamics.