A multi-faceted assessment of lake fish communities: implications for

conservation and restoration in France

Anthony MAIRE - Jean-Marc BAUDOIN - Christine ARGILLIERIRSTEA - UR HYAX

Pôle ONEMA-IRSTEA - Aix-en-Provence - France

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One of the final aims of the bioindication scheme is to prioritize management actions on the basis of these indices

However some aspects of the diversity of biological communities are not often accounted for:

Species conservation importance Socio-economic value of species Overall functional diversity …

BACKGROUND

Water Framework Directive (WFD)

2

Argillier et al. (2013)

Assessment of the ecological status of water bodiesBirk et al. (2012)

European Commission (2000)

Hering et al. (2010)

OBJECTIVE

To develop a complementary approach which:

3

3) Includes different facets of fish assemblage diversity and combines them into a prioritization framework

1) Focuses on fish assemblages in lakes

2) Relies on the data collected for the WFD

LAKES IN FRANCE & FISH DATA

Great environmental diversity of lakes

4 Focus on Natural Lakes

100 km

Quantitative sampling of fish assemblages Standardized fishing protocol (CEN prEN 14757) using multi-mesh gillnets

Comparable data on species abundance and biomass

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Gillnet

Lake shorelineNatural Lakes N = 46

Reservoirs N = 186

APPLICATION OF A MULTI-FACETED FRAMEWORK OF DIVERSITY

Adaptation of a framework previously developed on rivers

5

Maire et al. (2013)

Four non-redundant facets of diversity involving various quantitative indices

FACET 1: TAXONOMIC DIVERSITY

Species richness

Originality of the assemblage of species

Range-sized rarity of the species present

Maire et al. (2013)Fattorini (2006)6 Rutilus rutilus Salvelinus umbla

- +Rarity

FACET 2: FUNCTIONAL DIVERSITY

Trait diversity

Combination of life history and morphological traits

Type of trait Examples

Life history Feeding habitatBreeding habitat

Morphological Body depthMouth position

Removal of the redundancy among the 17 traits

Origin

ality

Uniqueness

7

Functional originality

Functional uniqueness

Buisson et al. (2013)

Schleuter et al. (2012)

FACET 3: CONSERVATION IMPORTANCE

Conservation status of the species present

8 Bergerot et al. (2008)

CR

Anguilla anguilla

Critically Endangered

Habitat Directive

VU

Coregonus lavaretus

Vulnerable LC

Esox lucius

Least Concern

Thymallus thymallus

Appendix V

Rhodeus amarus

Appendix III

FACET 4: SOCIO-ECONOMIC VALUE

Fishing interest of the species present

9 Maire et al. (2013)

Species without fishing interest

Species of interest for sportive anglers

Species of global interest for anglers and fishermen

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Lepomis gibbosus

Sander lucioperca

Cyprinus carpio

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AGGREGATION OF THE INDICES BY FACET

All the indices were computed on three fish data variants:1) Presence-absence (PA)2) Catch per unit effort (CPUE)3) Biomass per unit effort (BPUE)

10 Three values of each facet by lake

Standardisation of the indices and aggregation by facet

RESPONSE OF THE FACETS TO ENVIRONMENTAL PREDICTORS AND STRESSORS

Generalized Linear Models (GLM) with stepwise procedure

11

For each facet: PA, CPUE and BPUE variants were tested

Altitude

Maximum depth

Lake area

Catchment area

Mean annual temperature

Annual thermal range

Eutrophication:

Total Phosphorus (TP)

Proportion of Non-Natural Land-Covers in the catchment (NNLC)

Hydromorphological alterations:

Proportion of the lake shore altered (HM)

The variant with the ‘best model’ was selected

• Maximizing explained deviance• Mixing “natural” variability and significant

responses to stressors

Faceti ~ Environment1,…,n + Stressor1,…k

Generalized Linear Models (GLM) with stepwise procedure

Facet Variant R² Significant effect of stressors

TAXONOMIC PA 0.74 TP - NNLC - HM

FUNCTIONAL PA 0.62 TP

CONSERVATION PA 0.67 TP

SOCIO-ECONOMIC CPUE 0.77 TP - NNLC - HM

Socio-Economic Value (CPUE)

log(Total Phosphorus [µg/L]) log(Total Phosphorus [µg/L])

Conservation Importance (PA)

12

Final Synthetic Index = Sum of the 4 selected variants after standardization

For each lake: one synthetic value

= Preservation priority

RESPONSE OF THE FACETS TO ENVIRONMENTAL PREDICTORS AND STRESSORS

Synthetic Index = TAXO[PA] + FUNCT[PA] + CONSERV[PA] + SOCIO-ECO[CPUE]

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LAKE PRESERVATION PRIORITIES

100 km

log(Total Phosphorus [µg/L])

Final Synthetic Index

Final Synthetic Index

log(Maximum Depth [m])

+

-

Priority

ESTIMATION OF FACET VALUES UNDER REDUCED ANTHROPOGENIC STRESSORS

Hindcasting modelling of the reference conditions

Reduction of stressors to low values in the models

14 Launois et al. (2011); Maire et al. (2015)

New synthetic index value expected under low anthropogenic disturbances by summing the predicted values of the four facets

Facet ~ (Environment + Stressors) 1 Modelling - GLM

2Reference: Facet = Environment Stressors ≈ 0

4 Restoration potentialDeviation = Reference - Observed

3 ScoringReference: Synthetic Index = Σ Facets

Restoration priority

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LAKE RESTORATION PRIORITIES

100 km

+

-

Priority

Only 10% of the French natural lakes with high restoration priority

More than 50% of them with very low potential

No redundancy with the WFD national index (ELFI)

ρSpearman = 0.05

Original approach which provides two additional information regarding lake management priorities

Complementary to existing bioindication tools

Comparison with expert knowledge before validation by national authorities and local decision-makers

CONCLUSION & PERSPECTIVES

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Extension of this approach to Heavily Modified Water Bodies

4x more reservoirs than natural lakes in France

Relationships with the results obtained on rivers?

To bring new insights for a more integrative management at the catchment scale

100 km

+

-

Preservation Priority

THANK YOU

Contact anthony.maire@irstea.fr

Acknowledgments

We would like to thank all the territorial agents of the French National Agency for Water and Aquatic Environment (ONEMA) implied in the collection of the biological data.

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Bergerot, B. et al. (2008). Biodiversity and Conservation, 17.

Birk, S. et al. (2012). Ecological Indicators, 18.

Buisson, L. et al. (2013). Global Change Biology, 19.

European Commission. (2000). Official Journal of the European Communities.

Fattorini, S. (2006). Animal Conservation, 9.

Hering, D. et al. (2010). Science of The Total Environment, 408.

Launois, L. et al. (2011). Ecological Indicators, 11.

Maire, A. et al. (2013). Ecological Indicators, 34.

Maire, A. et al. (2015). Aquatic Conservation: Marine and Freshwater Ecosystems, in press.

Schleuter, D. et al. (2012). Global Ecology and Biogeography, 21.