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Reference conditions and class boundaries: Initial set of guidelines for reference conditions and class boundaries

Författare och institution:
Johnson Richard (-); Mats Lindegarth (Institutionen för biologi och miljövetenskap, Tjärnö marinbiologiska laboratorium); Jacob Carstensen (-)
Antal sidor:
University of Gothenburg
Sammanfattning (abstract):
The main purpose of this document is to provide guidance to improve assessment criteria for individual biological quality elements and to increase harmonisation of methods for establishing reference conditions and setting class boundaries within and among quality elements. This is done by establishing a common understanding of important concepts, identifying strengths and weaknesses of current approaches and suggesting ways forward towards an efficient and harmonised approach for defining reference conditions and class boundaries. Through discussions, an internal questionnaire and studies of the EU assessment of the Swedish WFD implementation, we identified challenges and potential solutions for issues concerning individual quality elements and, in terms of the overall coherence, of assessment criteria. Challenges in coastal waters are mainly associated with the definition and quantification of pressure criteria, which cause problems in the definition and harmonisation of reference conditions or alternative benchmarks. In inland waters challenges are associated with the efficiency and harmonisation of water body typologies and the definition of type-specific reference values. A general challenge for most biological quality elements in coastal and inland is to account for factors causing natural spatial variability within types as well as individual water bodies. As a result of these analyses we suggest the following priorities and guidelines for coming work within WATERS and projects related to the development of new assessment criteria for the WFD in Sweden: • Perform a systematic assessment and gap-analysis of pressures in coastal waters using existing data sources (measured and / or modelled) according to pressure types defined in annex 4, in order to define pressure criteria for reference conditions or more likely alternative benchmarks. • Use the newly developed typology for inland waters (or a revised version) as a framework for developing type-specific references and class boundaries for all quality elements as is currently done for coastal waters. • Use the proposed framework for modelling to explore the potential for empirical modelling using environmental factors to account for variability due to natural processes and thereby reduce uncertainty in ecological assessments.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
Geovetenskap och miljövetenskap ->
Geovetenskap och miljövetenskap ->
Oceanografi, hydrologi, vattenresurser
Biologiska vetenskaper ->
Postens nummer:
Posten skapad:
2015-07-03 16:43
Posten ändrad:
2015-08-18 08:53

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