Authors: Edel Hannigan and Mary Kelly-Quinn
Summary: This report is the Literature Review of the Rare Type project, which will help ensure that rare river types are categorised and assessed correctly as required by the WFD.
Ireland’s freshwaters are under pressure from a range of land-use and anthropogenic stressors. Inthe 2010 - 2012 monitoring period, 47% of the river water bodies monitored by the Environmental Protection Agency in Ireland failed to reach good ecological status, the minimum level required under the Water Framework Directive. Climate change coupled with future land-use intensificationmay further stress river systems potentially resulting in a reduction in the ecological status of numerous waterbodies. These challenges emphasise the need for the accurate assessment of the ecological status of aquatic resources. This report is the Literature Review of the RareType project,which will seek to determine if the current 12 national river types adequately represent rare rivertypes; and if the existing metrics accurately assess their status.
The Water Framework Directive is the key EU legislation requiring Member States to improve and sustainably manage and protect water quality in all surface water bodies. Under the WFD,all EU Member States are obliged to develop a river typology upon which type-specific reference conditions can be defined to enable accurate evaluation of ecological status. Ecological status isdetermined on the basis of deviation from these type-specific reference conditions. Rare river types were not adequately represented in the development of the existing national typology andso it is not known whether they are sufficiently characterised by the current 12 national river typesor represent distinct types. This report is the Literature Review of the RareType project, which will contribute to further refinement of the national typology by characterising the biological communities of rare rivers to determine if they represent distinct river types, and will assess the effectiveness of current metrics in determining their ecological status.
The first key step is to determine if the four categories of rare river type (naturally acid rivers, lakeoutlets, highly calcareous rivers, and groundwater-dominated rivers) examined in the RARETYPE project do in fact represent river types distinct from the 12 national types. If this is the case,then type-specific reference conditions must be established for the new types. This report is the Literature Review of the Rare Type project, which will help ensure that rare river types are categorised and assessed correctly as required by the WFD.
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