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Purine and pyrimidine bases in marine environmental particles collected in Harima-Nada, the Seto Inland Sea, Japan, were investigated by high performance liquid chromatography.Purines and pyrimidines concentrations varied from 0.3 to 9.3 μg l−1 (n=20) for suspended matter, and 0.3 to 0.6 mg g−1 (n=10) for sinking particles. A good correlation was found between chlorophyll a and purine+pyrimidine bases in suspended matter, indicating that these bases contained in suspended matter originated from phytoplankton.A comparison between several compositional data of the suspended matter and the sinking particles, namely CN ratio, composition of purines and pyrimidines, and percentages of the nitrogen bases relative to total particulate organic nitrogen, demonstrates that the sinking particles were different from suspended matter. Also, from the variety of purine and pyrimidine concentrations of marine particle samples, it was estimated that the decomposition rate of these bases seemed more rapid than decomposition rates of amino acids reported in our earlier study. 相似文献
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Submarine ground water discharge (SGD) rates were measured continuously by automated seepage meters to evaluate the process of ground water discharge to the ocean in the coastal zone of Suruga Bay, Japan. The ratio of terrestrial fresh SGD to total SGD was estimated to be at most 9% by continuous measurements of electrical conductivity of SGD. Semidiurnal changes of SGD due to tidal effects and an inverse relation between SGD and barometric pressure were observed. Power spectrum density analyses of SGD, sea level, and ground water level show that SGD near shore correlated to ground water level changes and SGD offshore correlated to sea level changes. SGD rates near the mouth of the Abe River are smaller than those elsewhere, possibly showing the effect of the river on SGD. The ratio of terrestrial ground water discharge to the total discharge to the ocean was estimated to be 14.7% using a water balance method. 相似文献
3.
Direct measurements of submarine groundwater discharge (SGD) over a fractured rock aquifer in Flamengo Bay Brazil 总被引:1,自引:0,他引:1
Henry Bokuniewicz Makoto Taniguchi Tomotoshi Ishitoibi Matthew Charette Matthew Allen Evgeny A. Kontar 《Estuarine, Coastal and Shelf Science》2008
Measurements of submarine groundwater discharge (SGD) along the South American coast and over fractured rock aquifers are rare. The rate and distribution of SGD was measured using three types of vented benthic chambers on the floor of Flamengo Bay located at the southeast coast of Brazil. Discharge rates were found up to almost 400 cm day−1, although typically less than 100 cm d−1. Large variations in SGD rates were seen over distances of a few meters which are attributed to the geomorphologic features of the fracture rock aquifer underlying a thin blanket of coastal sediments; clustering of fractures and the topography of the rock–sediment interface might be focusing or dispersing the discharge of groundwater. SGD was modulated by the tides with the highest values occurring at times of low tide, but the interaction was non-linear and, the correlation was weak at tidal ranges less than 1 m. The effect was masked by devices that integrated the SGD, but detected on continuously recording devices. 相似文献
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The phenomenon of rapid increase in water temperature accompanied by a sudden, swift current (Kyucho) in Uwajima Bay is described on the basis of results of long term observations from July 1985 to September 1986. This phenomenon occurs somewhat periodically with an interval of about 15 days in summer, although it does not occur in winter. The increase in water temperature occasionally reaches about 5°C. This phenomenon results from the intrusion of a warm water mass into the bay. NOAA-9 satellite images show that the warm water mass originates from the Pacific Ocean south of the Bungo Channel. 相似文献
5.
Tomotoshi Okaichi 《Journal of Oceanography》1983,39(5):267-278
The cause of red tides appearing in neritic waters in Japan have been discussed by several workers in relation to the development of eutrophication. The author has been engaged in marine environmental studies on outbreaks of red tides, mainly, in the Seto Inland Sea since 1964 using a combination of the following approaches:
- surveys of the red tides that have occurred,
- elucidation of the oceanographical and biological characters of the water areas where red tides occur,
- isolation of the red tide organisms for physiological studies of their growth,
- chemical and biological assays of the growth promoting factors, and
- estimation of the effects of pollutants on the growth of the red tide organisms.
6.
We investigated submarine ground water discharge and salt water-fresh water interactions at two locations along the shoreline of the Upper Gulf of Thailand to evaluate mechanisms of water and material transport into the coastal zone. Our data set illustrates the value of using a combined approach consisting of automatic seepage meters to monitor flow rates while assessing the conductivity (salinity) of the subterranean fluids via remote resistivity measurements. Negative correlations between electric conductivities of fluids measured directly inside seepage meter chambers and the remotely assessed resistivities of subsurface pore water show that such measurements may evaluate the spatial distribution of flow rates as well as the subterranean water quality in the coastal zone. Combined seepage and resistivity measurements may thus provide a more complete understanding of coastal ground water dynamics. 相似文献
7.
Large amorphous aggregates (NUTA) observed in coastal areas after spring and autumn phytoplankton blooms and red tide outbreaks
were collected using NUTA traps which we devised. These particles become thickly attached to mooring ropes and/or fishing
nets.
The variation of the collection of materials by NUTA traps was about 23% in organic carbon and 25% in organic nitrogen (n=29).
The chemical nature and vertical distribution pattern of NUTA were significantly different from those of suspended particles
collected by water samplers. Since C/ATP and C/Chlα ratios in NUTA were very high compared with those of suspended particles, NUTA seems to consist of a small amount of phytoplankton
but much detritus. These values suggest that NUTA has characteristics intermediate between suspended particles and sinking
particles. The standing stock of NUTA was also estimated to be no more than 10% suspended particles from a calculation of
the trapping efficiency of the NUTA trap. 相似文献
8.
William C. Burnett Gullaya Wattayakorn Makoto Taniguchi Henrieta Dulaiova Pramot Sojisuporn Sompop Rungsupa Tomotoshi Ishitobi 《Continental Shelf Research》2007
We report here the first direct measurements of nutrient fluxes via groundwater discharge into the Upper Gulf of Thailand. Nutrient and standard oceanographic surveys were conducted during the wet and dry seasons along the Chao Phraya River, Estuary and out into the Upper Gulf of Thailand. Additional measurements in selected near-shore regions of the Gulf included manual and automatic seepage meter deployments, as well as nutrient evaluations of seepage and coastal waters. The river transects characterized the distribution of biogeochemical parameters in this highly contaminated urban environment. Seepage flux measurements together with nutrient analyses of seepage fluids were used to estimate nutrient fluxes via groundwater pathways for comparison to riverine fluxes. 相似文献
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