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No.78 (2004/9) >

Title :Status of Organic and Inorganic Nutrients in Waters and Sediments at the Habitat of the Mangrove Sesarmid Crabs from the Ryukyu Islands, Japan
Authors :Islam, Md. Sirajul
Shokita, Shigemitsu
Mfilinge, Prosper L.
Tsuchiya, Makoto
Authors alternative :土屋, 誠
Issue Date :Sep-2004
Abstract :To estimate the relative importance of mangrove swamps for sesarmids habitat, total organic carbon (TOC) and inorganic nutrients in water, and the sediment C/N ratios were determined from three different sites of the Ryukyu Islands: the Shira River mangrove swamp at Iriomote Island, the Nuha River mangrove swamp at Okinawa Main Island, and the Nagura River mangrove swamp at Ishigaki Island, during December 2000, August 2001, and September 2002, respectively. The concentrations of total organic carbon in mangrove waters were 1.28, 1.52 and 0.60 ppm in the Shira, Nuha and Nagura rivers, respectively. The concentration of inorganic nutrients were determined from those mangrove waters are sodium (Na^+), potassium (K^+), ammonium (NH^+_4), chlorine (Cl^-), fluorine (F^-), bromine (Br^-), nitrate (NO^-_3), phosphate (PO^-2_4) and sulfate (SO^-2_4). No satisfactory explanation was found for the high concentrations of sodium and chlorine. The mangrove sediments C/N ratios were 17.9, 12.8 and 25.2 in the Shira, Nuha and Nagura rivers, respectively. The C/N ratio of Nuha river sediment was lower than that of the Shira and Nagura river, indicating higher nutritional value because of many organic matters decomposed here. Sediments from three mangroves had a mean C/N ratio of 18.6, indicating lower C/N ratios could be a richer source of nitrogen, which is regular ingestion by sesarmid crabs. Significant differences (P<0.0001) were found among the TOC concentrations in mangrove waters and C/N ratios in mangrove sediments from these three sites.
Type Local :紀要論文
ISSN :0286-9640
Publisher :琉球大学理学部
URI :http://hdl.handle.net/20.500.12000/13167
Citation :琉球大学理学部紀要 = Bulletin of the College of Science. University of the Ryukyus no.78 p.327 -356
Appears in Collections:No.78 (2004/9)

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