Bioassessment Techniques for Monitoring of Eutorphication and Nutrient Limitation in Coastal Ecosystems

摘要

Bioassesment by the use of the macroalga, Ulva lactuca L., was carried out in the Limfjord, Denmakr, to assess the significance of nitrogen and phosphorus as limting factors for primary production during 1985, 1993, 1994 and 1995 and for the detection of changes in eutrophication levels. Minimum and critical tissue concentrations for nitrogen And phosphorus in macroalgae were identified. The con- Centrations of nitrogen were generally below the critical Concentration level in June-October in 1985, 1993, and 1995 but in 1994 nitrogen was only limiting for primary production in short periods.