Study on Purification Ability for Water Quality in Tidal Flats in Hiroshima Bay-Evaluation for the Characteristics of Organic Matter Decomposition.

Annual sediment respiration in estuarine sandy intertidal flats in the Seto Inland Sea, Japan

“…A similar seasonal change in sediment respiration has been reported previously for other estuarine intertidal flats (van Es 1982;Middelburg et al 1995Middelburg et al , 1996. At our study site, the Therkildsen and Lomstein (1993) Tidally dominated bay Northern Waddesn Sea, Germany 2.7-4.3 b Kristensen et al (1997) Intertidal estuary Westerschelde Estuary, The Netherlands 2.2-6.3 b Middelburg et al (1996) Intertidal flat Hiroshima Bay, Japan 2.4-2.8 a Seiki et al (1998) Sublittoral area Sapelo Island, Georgia, USA 1.26-2.16 a Smith (1973) Intertidal esutary Kurose River Estuary, Japan 1.8 b Present study a Value was determined under submerged conditions b Value was determined under air-exposed conditions Landscape Ecol Eng (2012) 8:107-114 111 monthly respiration was minimum in February (4.7 g CO 2 -C m -2 ) and maximum in August (11.5 g CO 2 -C m -2 ). In terrestrial habitats, extremely low soil respiration in winter is common (e.g., Mariko et al 2000;Rayment and Jarvis 2000;Mo et al 2005).…”

“…Our results indicate that the estuarine intertidal flats contribute considerably to organic matter mineralization at the interfaces between terrestrial and marine White and black column shows sediment respiration under air-exposed and submerged conditions, respectively systems, although its area is only 0.2% of the terrestrial river basin area. Seiki et al (1998) Intertidal sandy flats at coast Island Sylt, Germany 500-767 a de Beer et al (2005) Intertidal sandy beach Eastern English Channel, France 15 b Spilmont et al (2005) Estuarine intertidal flats Ems-Dollard Estuary, The Netherlands 66-298 a van Es (1982) Estuarine intertidal flats Scheldt Estuary, The Netherlands 252 b Middelburg et al (1995) Estuarine intertidal flats Kurose River Estuary, Japan 92 c Present study a Measurement was conducted under submerged conditions; O 2 consumption rates were converted to CO 2 emission rates assuming the respiratory quotient was 1 b Measurement was conducted under air-exposed conditions c Value considering the variation of sediment respiration rates with temperature and tide Landscape Ecol Eng (2012) 8:107-114 113…”

“…Temperature is an important factor affecting sediment respiration rates in any terrestrial habitat, including intertidal flats (e.g., Raich and Schlesinger 1992;Lloyd and Taylor 1994;Middelburg et al 1996;Seiki et al 1998). At our study site, sediment respiration rates changed significantly with sediment temperature, and the seasonal variation in sediment respiration rates was largely explained by variation in the sediment temperature (r 2 = 0.70, p \ 0.05; Fig.…”

Tidal effects on the organic carbon mineralization rate under aerobic conditions in sediments of an intertidal estuary

“…Although some authors have reported CO 2 emission rates under air-exposed conditions (Middelburg et al 1996;Migne´et al 2002;Spilmont et al 2005), most investigations of benthic respiration in intertidal estuaries, including organic carbon mineralization rate, were conducted under submerged conditions (e.g., van Es 1982;Cammen 1991;Seiki et al 1998). Therefore, the amount of mineralized organic carbon in intertidal estuaries likely has been underestimated.…”

“…During the measurements, water temperature was kept at 20°C. Changes in O 2 concentration in the seawater were monitored with a dissolved oxygen meter (model 52, YSI Nanotech Inc.) for at least 5 h. For comparison with CO 2 emission rates, O 2 consumption rates were converted to CO 2 emission rates assuming a molar ratio of 1:1 (Seiki et al 1998).…”