Identification and interaction of multiple stressors in central European lowland rivers

Multiple stressors determine river ecological status at the European scale: Towards an integrated understanding of river status deterioration

“…More specifically, we expected nutrient enrichment to be particularly relevant for the ecological status of lowland rivers, whose catchments are often characterized by high agricultural intensities (Hypothesis 2.1; e.g. Lemm & Feld, 2017); hydrological alteration to be particularly relevant for river types with small and F I G U R E 1 Overview of the locations of 52,847 sub-catchment units and their ecological status class (grey area: no data available) medium size catchments or rivers in the Mediterranean, which are frequently affected by damming or water abstraction for irrigation (Hypothesis 2.2;Couto & Olden, 2018;Huđek et al, 2020;Panagopoulos et al, 2019); and toxic substances to mainly affect small streams in intensively used areas (Hypothesis 2.3;Beketov et al, 2013;Schäfer et al, 2013). We furthermore expected that riparian land use particularly impacts ecological status of small streams, which are more strongly affected by the immediate surrounding as compared to larger rivers, for which cumulative stressors at catchment scale are more relevant (Hypothesis 2.4;Fuller & Death, 2018).…”

Quantifying multiple pressure interactions affecting populations of a recreationally and commercially important freshwater fish

“…Species that are mobile enough have been reported to move into higher latitudes and elevations (Chen, Hill, Ohlemüller, Roy, & Thomas, 2011;Fogarty, Burrows, Pecl, Robinson, & Poloczanska, 2017), whereas less mobile species or those found in isolated habitats are forced to adapt (Isaak, Young, & Luce, 2016;Rohr & Palmer, 2013 (Clapcott, Collier, & Death, 2012). Global-and watershedscale investigations especially illustrate the asymmetric distribution of indicators and pressures (Halpern et al, 2015;Kalogianni et al, 2017;Lemm & Feld, 2017). There are numerous analytical techniques to uncover the effects of multiple pressures (Feld et al, 2016;Ferguson, Carvalho, & Scott, 2008), yet few options exist to address the inherent correlations of these often broadly distributed data.…”

Decline of freshwater gastropods exposed to recurrent interacting stressors implying cyanobacterial proliferations and droughts

“…Disentangle intricate effects of multiple interacting stressors, and related stresses, on freshwater biota over time in the field is challenging and of growing interest for scientists (Fischer et al 2013;Lemm and Feld 2017). Our field survey contributes to study responses of gastropods to two frequent combined stressors recurrent in stagnant waters, i.e., toxic cyanobacteria proliferations and droughts, typically occurring during summer in most temperate regions (Chorus and Bartram 1999;Lake 2000;Gérard et al 2008).…”

“…Therefore, freshwater biota increasingly suffer from exposure to multiple abiotic and biotic stressors that threaten biodiversity (e.g., Vinebrooke et al 2004;Dewson et al 2007;Gérard et al 2008;Strayer 2010;Nunes et al 2015;Botana 2016). Stressors can be punctual, recurrent or continuous; consequently, organisms usually undergo combined mixtures of interacting stressors, which effects may be synergistic, but are often unknown or difficult to predict (Holmstrup et al 2010;Lemm and Feld 2017).…”

“…Because of the health hazard for biota induced by exposure to multiple stressors, there is a growing interest on this research topic (Fischer et al 2013;Lemm and Feld 2017). Unfortunately, we still poorly understand to what extent interactive effects of multiple recurrent and concomitant stressors (and related stresses) influence the dynamics of community structure, potentially inducing resistance, resilience or decline of the populations depending on their sensitivity (Connell and Sousa 1983).…”