Can a priori defined reference criteria be used to select reference sites in Danish streams? Implications for implementing the Water Framework Directive.

An important step in the implementation of the Water Framework Directive is to define and characterize the natural status, designated as the reference condition (RC). Here we present the results of a type-specific screening for reference stream sites in Denmark using two different approaches. First, we performed a screening applying physicochemical, hydro-morphological and pressure criteria at the catchment, reach and site level of a total of 128 sites a priori selected by the regional water authorities as representing the best sites in Denmark.

The new Danish stream monitoring programme (NOVANA)--preparing monitoring activities for the Water Framework Directive era.

Denmark has a long tradition of monitoring the aquatic environment. Previous monitoring has mainly focused on loss of nutrients and subsequent impacts on the biological structure in lakes and coastal areas. However, as part of the third Action Plan for the Aquatic Environment more emphasis has been put on stream ecology.