Elsevier

Ecological Indicators

Volume 23, December 2012, Pages 56-65
Ecological Indicators

Ecological assessment of running waters: Do macrophytes, macroinvertebrates, diatoms and fish show similar responses to human pressures?

https://doi.org/10.1016/j.ecolind.2012.03.010Get rights and content

Abstract

This study aimed to compare the intensity and the sensitivity of the responses of four river biological quality elements (BQEs) – macrophytes, fish, diatoms and macroinvertebrates – to human pressures excluding natural variations in stream ecosystem functioning. Biological, water quality and hydro-morphological data were compiled for 290 French river sites.

Out of the 93 metrics tested, 51 covering the four BQEs responded significantly to global degradation. The responses to specific pressures were consistent with the BQEs’ ecological and biological characteristics. For the four BQEs, metrics responded strongly to water quality degradations. Like fish, macroinvertebrate metrics were very sensitive to morphological degradations such as the presence of an impoundment, while diatom and macrophyte metrics did not show strong responses to these changes. Among the four BQEs’ metrics, fish metrics responded the strongest to hydrological perturbations. Although a high proportion of the metrics responded only to high levels of human-induced degradations, trait-based metrics seemed the most sensitive and responded to lower levels of pressure. Global and water quality degradations of the river appear to be better detected by BQE metrics than channel morphological and hydrological degradations. Our results highlight the different impacts of human-induced pressures on the four BQE metrics and the challenging task of assessing the effect of single pressures when most of sites are multi-impacted.

Highlights

► Macrophyte, fish, diatom and macroinvertebrate responses to human-induced pressures were compared. ► Natural environmental variability was discarded from the analysis. ► Functional trait-based metrics were the most sensitive to changes. ► Depending on their ecological and biological characteristics, biological groups showed different responses. ► Multi-impacted sites had to be removed from the analysis to detect specific pressures.

Introduction

Throughout Europe, streams have experienced a long history of modification by humans (Petts, 1989) and have become one of the most threatened ecosystems (Loh et al., 2005). Since 2000, the Water Framework Directive (EC, 2000) recommends the use of multiple biological quality elements (BQEs) to assess “ecological status” of rivers. Given these institutional needs, freshwater scientists have developed numerous tools based on various concepts and biological indicators. Historically, biological responses were examined through metrics focusing on sensitive taxa (e.g. the Saprobic index, Pantle and Buck, 1955). More recently, Southwood (1977) and Townsend and Hildrew (1994) have put forward the idea that combinations of functional traits (ecological and biological) are selected by habitat conditions through the survival ability of individual organisms relative to others (i.e. their fitness). Such integrative approaches were based on the functional structures of fish (Fausch et al., 1990; Index of Biotic Integrity, IBI: Karr, 1981) and macroinvertebrate assemblages (Statzner et al., 2001, Usseglio-Polatera et al., 2000). It is of primary importance to gain a comparative idea of the sensitivity and efficiency of these different indicators in detecting river human-induced degradations.

Responses to human-induced disturbances in rivers have frequently been analysed separately for macroinvertebrates (Archaimbault et al., 2010, Lorenz et al., 2004, Statzner et al., 2001), diatoms (Besse-Lototskaya et al., 2011, Carpenter and Waite, 2000, Fore and Grafe, 2002), macrophytes (Lacoul and Freedman, 2006, Riis et al., 2000) and fish (D’Ambrosio et al., 2009, Pont et al., 2006, Pont et al., 2007, Yates and Bailey, 2010). Nonetheless, only a few authors have compared different assemblage responses to anthropogenic pressures. These studies have shown that metric response patterns (Johnson and Hering, 2009) and robustness (Johnson et al., 2006a) differ considerably among BQEs and stressors and with stream type (Heino, 2010, Hering et al., 2006). For instance, it appears likely that hydro-morphological degradations affect fish and macrophyte assemblages more than diatoms and macroinvertebrates (Hughes et al., 2009, Johnson et al., 2006b). More generally, the responses of the four BQEs seem stronger for water quality than for hydro-morphological degradations (Hering et al., 2006).

Some authors have demonstrated that trait-based metrics (MetFUNC) such as the number of euryplastic taxa show the highest sensitivity to human disturbance (Dolédec et al., 2006, Usseglio-Polatera et al., 2000). However, previous studies often investigated metrics based on the taxonomic composition (MetTAX) such as the total number of species (Heino et al., 2005, Johnson and Hering, 2009) rather than trait-based metrics (Hering et al., 2006, Hughes et al., 2009, Johnson et al., 2006a, Johnson et al., 2006b, Justus et al., 2010). In addition, as streams are frequently impacted by multiple stressors, single effects of stressors on BQEs have rarely been assessed (Hughes et al., 2009). Based on this literature review, we expected that biological assemblages would present different responses to human disturbances in terms of intensity (i.e. discriminatory efficiency; Ofenböck et al., 2004) and sensitivity (i.e. impact of a low level of pressure). Also, it was assumed that responses to pressures would be stronger for indexes (MetIND) and MetFUNC than for MetTAX and that the standardization method would allow analysing BQE responses along the main environmental gradients.

Comparing the responses of macrophytes, fish, diatoms and macroinvertebrates to different human pressures, this paper attempts to answer the following questions:

  • (1)

    Are the intensity and sensitivity of the responses to a general degradation gradient similar among BQEs?

  • (2)

    Do all BQEs detect specific pressures similarly (hydrological, morphological, and water quality degradations)?

  • (3)

    Do these responses to specific pressures change when only sites impacted by this pressure are considered?

  • (4)

    Which type of metric (MetIND, MetTAX and MetFUNC) is more appropriate to detect human pressure impacts?

We focused on a French data set covering a large range of environmental conditions and human-induced pressures. As pointed out by Stoddard et al. (2006), “natural variability in indicators always occurs” and has to be considered when measuring the deviation of ecosystems from a reference status. In this paper, the reference status was recognized as the minimally disturbed conditions (Stoddard et al., 2006). In contrast to the previous studies cited above, physiography (i.e. environmental factors assumed to be independent of human activity such as the geology or the altitude) effects were beforehand differentiated from human pressure effects, standardizing the metrics (Oberdorff et al., 2001, Pont et al., 2006, Pont et al., 2007).

Section snippets

Data compilation

For each of the four BQEs, one sample from French monitoring programs was compiled for 290 French river sites (Fig. 1) distributed along the main environmental gradients (e.g. altitude, geology). Very large rivers (upstream drainage area > 14,000 km2) were not considered. When several samples were available, the most recent was chosen (samples from 2005 to 2008). During these programs, fish (AFNOR, 2004a), macroinvertebrates (AFNOR, 2004b), macrophytes (mainly aquatic phanerogams, bryophytes and

Physiographic gradients and anthropogenic pressure indices

The first three axes of the physiographic variable analysis accounted for 53.5% of the total inertia with PG1, PG2 and PG3 explaining 31.6, 12.5 and 9.3%, respectively. PG1 was related to a longitudinal gradient, which increased with altitude and mean slope and decreased with mean width and catchment area. PG2 was related to the same variables but did not suggest a clear interpretation. PG3 was related to geological types from siliceous to calcareous.

The global synthetic pressure index

Discussion

The main purpose of this study was to test whether river assemblage responses to human-induced changes were similar among macrophytes, diatoms, fish and macroinvertebrates. More particularly, the potential to detect human-induced changes was compared in terms of intensity of the response (i.e. discriminatory efficiency) and sensitivity to changes (i.e. first significant responses occurring along pressure gradients). Metrics were transformed beforehand to retain only the proportion of the signal

Conclusions

This study demonstrates that the two main sources of variability in biological assemblages (physiography diversity and anthropogenic disturbances) should be distinguished a priori when looking at the impacts of human-induced stressors. Also, when selecting the best BQEs or metrics to detect stressor impacts, particular care should be taken when selecting the type of metric to study. Indeed, indexes and functional trait-based metrics tend to detect human-induced changes better (stronger

Acknowledgements

This paper is part of the WISER project (Water bodies in Europe: Integrative Systems to assess Ecological status and Recovery) funded by the European Union under the 7th Framework Programme, Theme 6 (Environment including Climate Change) (contract no. 226273), www.wiser.eu. It has been supported by the collaborative project “HYNES” between Irstea and the Research and Development Department of the French Electric Company (EDF). We thank Philippe Usseglio-Polatera, Martial Ferreol and the

References (55)

  • AFNOR

    Qualité de l’eau – Détermination de l’indice poissons rivières (IPR)

    (2004)
  • AFNOR

    Qualité écologique des milieux aquatiques. Qualité de l’eau – Détermination de l’indice biologique global normalisé (IBGN)

    (2004)
  • AFNOR

    Qualité de l’eau – Détermination de l’Indice Biologique Diatomées (IBD)

    (2007)
  • V. Archaimbault et al.

    Assessing pollution of toxic sediment in streams using bio-ecological traits of benthic macroinvertebrates

    Freshw. Biol.

    (2010)
  • R.M. Baxter

    Environmental effects of dams and impoundments

    Annu. Rev. Ecol. Syst.

    (1977)
  • K.D. Carpenter et al.

    Relations of habitat-specific algal assemblages to land use and water chemistry in the Willamette Basin

    Oregon. Environ. Monit. Assess.

    (2000)
  • J.L. D’Ambrosio et al.

    Effects of geomorphology, habitat, and spatial location on fish assemblages in a watershed in Ohio, USA

    Environ. Monit. Assess.

    (2009)
  • S. Dolédec et al.

    Comparison of structural and functional approaches to determining landuse effects on grassland stream invertebrate communities

    J. N. Am. Benthol. Soc.

    (2006)
  • EC

    2000/60/EC, Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy

    Off. J. Eur. Commun.

    (2000)
  • K.D. Fausch et al.

    Fish communities as indicators of environmental degradation

  • L.S. Fore et al.

    Using diatoms to assess the biological condition of large rivers in Idaho (USA)

    Freshw. Biol.

    (2002)
  • French Water Agency

    Système d’évaluation de la qualité des cours d’eau. Rapport de présentation SEQ-Eau. Etudes des Agences de l’Eau 64

    (2000)
  • B. Genin et al.

    Cours d’eau et indices biologiques pollution, méthodes, IBGN

    (2003)
  • F.E. Harrel

    Regression Modelling Strategies: With Applications to Linear Models, Logistic Regression, and Survival Analysis

    (2001)
  • J.A. Hartigan et al.

    Algorithm AS136: a k-means clustering algorithm

    Appl. Stat.

    (1979)
  • J. Haury et al.

    A new method to assess water trophy and organic pollution – the macrophyte biological index for rivers (IBMR): its application to different types of river and pollution

    Hydrobiologia

    (2006)
  • J. Heino et al.

    Searching for biodiversity indicators in running waters: do bryophytes, macroinvertebrates, and fish show congruent diversity patterns?

    Biodivers. Conserv.

    (2005)
  • Cited by (153)

    • Class Hexapoda: general introduction

      2023, Identification and Ecology of Freshwater Arthropods in the Mediterranean Basin
    View all citing articles on Scopus
    View full text