Louisiana inputs

Variation among Sampling Sites. Dissolved humic substance samples from seven end-member environments were isolated for study. Autochthonous inputs to DOM were expected to dominate in Big Soda Lake and in Island Lake, which is a groundwater-sustained eutrophic lake in the sandhills of western Nebraska. Allochthonous inputs to DOM from a swamp environment predominate in the Suwannee River. They also dominate in the Calcasieu River in western Louisiana, but the proportion of swampland is much lower there. The Temi River is a tropical blackwater tributary of the Orinoco River in Venezuela, where allochthonous inputs dominate. The entire Sagavanirktok River basin is located north of the tree line on the North Slope of Alaska a mixture of allochthonous and autochthonous inputs was expected for the various rivers and lakes in this basin. Lastly, Hidden Lake Creek, which is the outlet of Hidden Lake on the Kenai Peninsula of Alaska, was sampled to determine if nutrient inputs from decaying salmon were contributing to primary production and autochthonous inputs to DOM. 

In a summary of 1975-1979 data on fish tissue from EPA s STORET database, the mean concentration of silver in 221 samples was 0.225 mg/kg (wet weight total fish), with a range of 0.004-1.900 mg/kg (Scowetal. 1981). In Lake Pontchartrain, Louisiana (which is likely to receive substantial inputs of metals from municipal and agricultural activities) silver concentrations in clams and American oyster tissues were 0.4-2.4 mg/kg and 5.5 mg/kg (all dry weight), respectively (Byrne and DeLeon 1986). 

Galveston Bay II (Louisiana and Alabama) 420-480 Source input in low-salinity region in July Guo and Santschi (1997)... 

The Louisiana sites so far ranked using draft guidance for data input to the model have not scored high, compared to many other sites in the nation. In general, two factors account for the relatively low scores (1) low population density (except in one case) and (2) subsurface geology and hydrology that tends to minimize potential for groundwater contamination. 

Results demonstrate that Louisiana swamp forests play an important role in controlling eutrophication and improving the deteriorating water quality caused by nutrient inputs from agricultural and municipal discharges. Nitrification-denitrification reactions are important as a removal mechanism for nitrogen entering the coastal Louisiana wetlands. 

List the major nitrogen inputs into Louisiana coastal wetlands. 

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