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Title: Impacts of Nutrients in Estuaries - Phase 2
Author: C R Scott
Author: K L Hemingway
Author: M. Elliott
Author: V N De Honge
Author: J S Penthick
Author: S. Malcolm
Author: M. Wilkinson
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_284, Representation ID: 53, Object ID: 1630
The Agency and English Nature commissioned this review of literature and expert opinion on the impact of nutrients in estuaries as an important step towards delivering the sound, scientific foundations on which effective management strategies must be based. There do not appear to be any examples of ccmplete management strategies on estutine eutrophication, although certain elements of such strategies do exist, for example, assessment and classification schemes. These qualitatively, or semi-quantitatively, describe the nutrient or trophic status of estuaries, or distinguish their differing ecological susceptibilities to nutrient impacts (allowing priorities to be identified). A scheme is proposed, in this latter category, as a generic framework for screening the eutrophication-risk of estuaries. The classification criteria are physico-chemical parameters (nutrient input, turbidity, flushing time, etc.). As a broad-brush approach, this would not be applicable in issue-driven situations (eg. SACS, SPAS, etc.), where detailed information has already been collected. A further fundamental challenge to management is the setting of relevant targets, and the most likely way forward is seen in the development of Ecological Quality Objectives (EcoQO’s), as established, conceptually, in OSPAR and EU discussions on environmental protection. Key estuarine communities are identified, and high level objectives established for them, eg, for saltmarshes, it is suggested that there should be no persistent decline in area1 coverage or productivity, relative to all other estuarine vegetation, nor increase in plant tissue nutrient levels, over specified timescales. Such nascent EcoQOs clearly need further development and trialling. The classification and EcoQOs are two key elements of a proposed four-stage process for managing nutrient impacts on water quality and conservation interest, in the estuaries of England and Wales: - screening to identify priorities; - assessing, in detail, the status of those priority sites; - setting specific objectives for the sites; - taking appropriate action and monitoring to assess progress towards the objectives. This proposal extends the approach already used to examine estuarine nutrient impacts, in the context of the EC Urban Waste Water Treatment, Nitrate and Habitats Directives, to a more generic and widely applicable process.
Publisher: Environment Agency
Subject Keywords: EstuariesWater pollutionWater qualityEnvironmental protectionPhosphorusSediment pollutionNutrientsEutrophicationQualityStandardsBrackishwater environment
Geographic Keywords: EnglandWalesBritish Isles
Extent: 234
Total file downloads: 320

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