Hydrodynamic control of nitrogen and phosphorus turnover in an eutrophicated estuary in the Baltic.
The turnover of phosphorus and nitrogen have been studied in a low salinity estuary in the Bothnian Sea. The estuary, Gårdsfjärden, has a high loading of nutrients from a pulp and paper mill which supplies the estuary with three times the annual natural input of phosphorus and nitrogen, respectively. The turnover of nutrients was to a great extent determined by hydrodynamic variations. During periods of intense resuspension there was a net export of particulate bound nutrients from the estuary to the sea but since these periods were short there was an overall net retention of particulate nutrients. The estuary was a source for dissolved phosphorus to the sea. The major source of phosphorus export was release of dissolved P from anoxic sediments. Gårdsfjärden was a sink for dissolved nitrogen which most likely escaped the estuary by denitrification. Nitrate was supplied by degradation of particulate organic nitroge'n but the main source was import from the sea.
Nilsson
Per
P
Department of Ecology and Environmental Science, Umeå University, Sweden. per.nilsson@mh.se
Jansson
Mats
M
D001454:Baltic States; D017753:Ecosystem; D005068:Eutrophication; D019015:Geologic Sediments / Q000737:chemistry; D007220:Industrial Waste; D009584:Nitrogen / Q000378:metabolism*; D010209:Paper; D010758:Phosphorus / Q000378:metabolism*; D014873:Water Pollutants / Q000378:metabolism*
D007220:Industrial Waste; D014873:Water Pollutants; D010758:Phosphorus; D009584:Nitrogen