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Title: Coastal baseline survey 1990-93. Part 1 : nutrients
Author: National Rivers Authority
Document Type: Monograph
The Southern Region Coastal Baseline Survey was initiated in 1990 to determine concentrations of nutrients, metals and organic pesticides in coastal waters. Twenty four stations have been sampled four times per annum since December 1990. This report presents results for nutrients over the period 1990 to November 1993. The full programme will terminate in March 1994 and a final report will be circulated. Future monitoring requirements are currently being reviewed both Nationally and Regionally. Future monitoring needs in Southern Region will be established by these reviews. Gradients of nutrient concentration were evident in major estuaries such as the Thames and Solent. Concentrations were higher in the estuaries than in adjacent coastal waters reflecting the importance of rivers as sources of nutrients. Concentrations were higher during the winter than the summer, again reflecting the importance of rivers, which generally discharge higher volumes during the winter period. There was little evidence of local effects from rivers discharging to the coasts of southern Kent and Sussex. Here, sampling stations were located off shore and the plumes from the relatively small rivers are dispersed close to the shore. Levels of nutrients during the summer months were reduced due to low river discharge and uptake by phytoplankton. Concentrations of chlorophyll A were generally higher during the summer period although peak bloom events occurred earlier during the Spring in some locations. There was evidence that in sheltered waters with restricted dispersion, for instance the Solent, concentrations of chlorophyll A can exceed the level at which waters are deemed to be susceptible to eutrophication. Supersaturation in terms of dissolved oxygen during the day, might be indicative of reduced night time concentrations, a further indicator of eutrophication susceptibility.
Publisher: National Rivers Authority
Publication Date: 1994
Publication Place: Worthing
Subject Keywords: SamplingNutrientsEstuariesDissolved oxygenEutrophication
Geographic Keywords: Thames Estuary
Extent: 7; + figures and tables
Total file downloads: 246

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