The impact of climate-induced distributional changes on the validity of biological water quality metrics

Christopher Hassall,David J Thompson,Ian F Harvey

doi:10.1007/s10661-008-0709-4

Christopher Hassall, David J Thompson + Show 1 more

Open Access

https://doi.org/10.1007/s10661-008-0709-4

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Abstract

We present data on the distributional changes within an order of macroinvertebrates used in biological water quality monitoring. The British Odonata (dragonflies and damselflies) have been shown to be expanding their range northwards and this could potentially affect the use of water quality metrics. The results show that the families of Odonata that are used in monitoring are shifting their ranges poleward and that species richness is increasing through time at most UK latitudes. These past distributional shifts have had negligible effects on water quality indicators. However, variation in Odonata species richness (particularly in species-poor regions) has a significant effect on water quality metrics. We conclude with a brief review of current and predicted responses of aquatic macroinvertebrates to environmental warming and maintain that caution is warranted in the use of such dynamic biological indicators.

Highlights

Freshwater systems are vital for life and the strain that increasing human population densities place upon them means that careful monitoring is required to avoid overexploitation (Chapman, 1996; Dudgeon et al, 2006)
It is clear from this figure that the trend in average score per taxon (ASPT), statistically significant, does not mirror the changing species richness
At low species richness the odonate ASPT is relatively low and it is not until species richness increases that this equilibrates

Summary

Introduction

Freshwater systems are vital for life and the strain that increasing human population densities place upon them means that careful monitoring is required to avoid overexploitation (Chapman, 1996; Dudgeon et al, 2006). The scores for all families present in a given stretch of river are totalled and divided by the number of contributing families to find an average score per taxon (ASPT) Since the original scheme was designed, scores for each taxon have been revised in light of computer analyses by Walley and Hawkes (1996; 1997), leading to a reduction in the uniformity of scores between same-order families

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