Human pressures and ecological status of European rivers

Abstract

Humans have increased the discharge of pollution, altered water flow regime and modified the morphology of rivers. All these actions have resulted in multiple pressures on freshwater ecosystems, undermining their biodiversity and ecological functioning. The European Union has adopted an ambitious water policy to reduce pressures and achieve a good ecological status for all water bodies. However, assessing multiple pressures on aquatic ecosystems and understanding their combined impact on the ecological status is challenging, especially at the large scale, though crucial to the planning of effective policies. Here, for the first time, we quantify multiple human pressures and their relationship with the ecological status for all European rivers. We considered ecological data collected across Europe and pressures assessed by pan-European models, including pollution, hydrological and hydromorphological alterations. We estimated that in one third of EU’s territory rivers are in good ecological status. We found that better ecological status is associated with the presence of natural areas in floodplains, while urbanisation and nutrient pollution are important predictors of ecological degradation. We explored scenarios of improvement of rivers ecological status for Europe. Our results strengthen the need to halt urban land take, curb nitrogen pollution and maintain and restore nature along rivers.

Pan-European Calculation of Hydrologic Stress Metrics in Rivers: A First Assessment with Potential Connections to Ecological Status

“…To be able to determine required hydrologic conditions for preserving good ecological status, for example, with regard to minimum ecological flows [62], the present results should be updated based on much longer simulated time-series of flow. But more importantly, they should be associated with large datasets of reported local ecological status of rivers (see Grizzetti et al, [63]). In addition, the water demand estimates highly depend on global datasets.…”

Development of a procedure for determining the basic parameter of aquatic ecosystems functioning ‒ environmental capacity

“…where С i.act is the actual concentration of the i-th hydro-chemical or trophic-saprobiological factor; C i.opt is the optimum concentration of the i-th hydro-chemical factor (or MAC). The degree of water pollution in the body under study is characterized according to the generalized indicator of water pollution (IWP) which is equal to the arithmetic average: 1…”

“…It is important to note that the problem of stable functioning of aquatic ecosystems is characteristic of virtually all European river basins. Despite EU laws and numerous directives, only 40 % of surface water bodies surveyed by the European Environment Agency (EEA) correspond just to "good" ecological status [1].…”

The growing role of aquaculture in ecosystem restoration

“…Human activities have substantial, spatially variable impacts on oceans (Halpern et al 2008) and freshwater systems (Jenny et al 2016;Grizzetti et al 2017). Affected ecological processes include connectivity (Allendorf et al 2015), trophic exchange (Malhi et al 2016), and succession (Sandin & Sala 2012).…”