Assessing river biotic condition at a continental scale: a European approach using functional metrics and fish assemblages

Summary 1. The need for sensitive biological measures of aquatic ecosystem integrity applicable at large spatial scales has been highlighted by the implementation of the European Water Framework Directive. Using fish communities as indicators of habitat quality in rivers, we developed a multi-metric index to test our capacity to (i) correctly model a variety of metrics based on assemblage structure and functions, and (ii) discriminate between the effects of natural vs. human-induced environmental variability at a continental scale. 2. Information was collected for 5252 sites distributed among 1843 European rivers. Data included variables on fish assemblage structure, local environmental variables, sampling strategy and a river basin classification based on native fish fauna similarities accounting for regional effects on local assemblage structure. Fifty-eight metrics reflecting different aspects of fish assemblage structure and function were selected from the available literature and tested for their potential to indicate habitat degradation. 3. To quantify possible deviation from a ‘reference condition’ for any given site, we first established and validated statistical models describing metric responses to natural environmental variability in the absence of any significant human disturbance. We considered that the residual distributions of these models described the response range of each metric, whatever the natural environmental variability. After testing the sensitivity of these residuals to a gradient of human disturbance, we finally selected 10 metrics that were combined to obtain a European fish assemblage index. We demonstrated that (i) when considering only minimally disturbed sites the index remains invariant, regardless of environmental variability, and (ii) the index shows a significant negative linear response to a gradient of human disturbance. 4. Synthesis and applications . In this reference condition modelling approach, by including a more complete description of environmental variability at both local and regional scales it was possible to develop a novel fish biotic index transferable between catchments at the European scale. The use of functional metrics based on biological attributes of species instead of metrics based on species themselves reduced the index sensitivity to the variability of fish fauna across different biogeographical areas.

[1]  E. Balon,et al.  Reproductive Guilds of Fishes: A Proposal and Definition , 1975 .

[2]  J. Stauffer,et al.  Regional Frameworks and Candidate Metrics for Assessing Biotic Integrity in Mid-Atlantic Highland Streams , 2000 .

[3]  P. Giller River restoration: seeking ecological standards. Editor's introduction , 2005 .

[4]  Donald J. Orth,et al.  Application and Testing of an Index of Biotic Integrity in Small, Coolwater Streams , 1986 .

[5]  R. Hey,et al.  River rehabilitation and fish populations: assessing the benefit of instream structures , 2003 .

[6]  P. Bănărescu Zoogeography of fresh waters , 1991 .

[7]  P. Angermeier,et al.  Using Fish Communities to Assess Streams in Romania: Initial Development of an Index of Biotic Integrity* , 2004, Hydrobiologia.

[8]  S. Ormerod Current issues with fish and fisheries: editor's overview and introduction , 2003 .

[9]  P. McCullagh,et al.  Generalized Linear Models , 1992 .

[10]  Russell G. Death,et al.  Predictive modelling of freshwater fish as a biomonitoring tool in New Zealand , 2002 .

[11]  T. Simon,et al.  Modification and assessment of an index of biotic integrity to quantify water resource quality in great rivers , 1995 .

[12]  R. Hughes,et al.  A process for developing and evaluating indices of fish assemblage integrity , 1998 .

[13]  Thierry Oberdorff,et al.  Development and validation of a fish-based index for the assessment of ‘river health’ in France , 2002 .

[14]  Steve L. Schleiger Use of an Index of Biotic Integrity to Detect Effects of Land Uses on Stream Fish Communities in West‐Central Georgia , 2000 .

[15]  T. Northcote,et al.  Migratory Behaviour of Fish and its Significance to Movement through Riverine Fish Passage Facilities , 1998 .

[16]  Robert C. Bailey,et al.  Biological assessment of freshwater ecosystems using a reference condition approach: comparing predicted and actual benthic invertebrate communities in Yukon streams , 1998 .

[17]  Robert M. Hughes,et al.  Development of an Index of Biotic Integrity for the Mid-Atlantic Highlands Region , 2001 .

[18]  R. Hughes,et al.  A regional framework for establishing recovery criteria , 1990 .

[19]  J. Karr Assessment of Biotic Integrity Using Fish Communities , 1981 .

[20]  R. Hughes,et al.  An Index of Biological Integrity (IBI) for Pacific Northwest Rivers , 2003 .

[21]  W. J. Matthews,et al.  Patterns in Freshwater Fish Ecology , 1998, Springer US.

[22]  Stanley V. Gregory,et al.  Electrofishing Effort Requirements for Assessing Species Richness and Biotic Integrity in Western Oregon Streams , 2003 .

[23]  Erich Emery,et al.  Development of a Multimetric Index for Assessing the Biological Condition of the Ohio River , 2003 .

[24]  S. Weisberg,et al.  Maryland Biological Stream Survey: Development of a Fish Index of Biotic Integrity , 1998 .

[25]  Hilary E. Berkman,et al.  Effect of siltation on stream fish communities , 1987, Environmental Biology of Fishes.

[26]  J. Harris,et al.  Large‐scale assessments of river health using an Index of Biotic Integrity with low‐diversity fish communities , 1999 .

[27]  Robert G. Bailey,et al.  DISTINGUISHING BETWEEN WATERSHEDS AND ECOREGIONS 1 , 1997 .

[28]  R. Hughes,et al.  A Biointegrity Index (IBI) for Coldwater Streams of Western Oregon and Washington , 2004 .

[29]  J. Karr,et al.  Restoring life in running waters : better biological monitoring , 1998 .

[30]  I. Schlosser,et al.  Species-Area Relationship for Stream Fishes , 1989 .

[31]  J. Lyons,et al.  Index of Biotic Integrity Based on Fish Assemblages for the Conservation of Streams and Rivers in West‐Central Mexico , 1995 .

[32]  I. Schlosser,et al.  FISH COMMUNITY STRUCTURE AND FUNCTION ALONG TWO HABITAT GRADIENTS IN A HEADWATER STREAM , 1982 .

[33]  Assessing Biotic Integrity of the Fish Community in a Small Illinois Stream , 1987 .

[34]  Determining a Regional Framework for Assessing Biotic Integrity of Virginia Streams , 2001 .

[35]  J. Meyer,et al.  Standards for ecologically successful river restoration , 2005 .

[36]  D. Pont,et al.  A probabilistic model characterizing fish assemblages of French rivers: a framework for environmental assessment , 2001 .

[37]  P. Bănărescu Zoogeography of fresh waters. Volume 2: distribution and dispersal of freshwater animals in North America and Eurasia. , 1991 .

[38]  John A. Wiens,et al.  Species diversity in ecological communities: edited by Robert E. Ricklefs and Dolph Schluter University of Chicago Press, 1993. $105.00 hbk, $35.00 pbk (414 pages) ISBN 0 226 71822 0/0 226 71823 9 , 1994 .

[39]  Thomas P. Simon,et al.  Assessing the Sustainability and Biological Integrity of Water Resources Using Fish Communities , 2020 .

[40]  Thierry Oberdorff,et al.  Modelling habitat requirement of European fishes: do species have similar responses to local and regional environmental constraints? , 2005 .