Physical and chemical water requirements of the white‐clawed crayfish (Austropotamobius pallipes) in western France

Abstract

ABSTRACT1. In France, the distribution of the native white-clawed crayfish (Austropotamobius pallipes) is restricted, fragmented and mainly located in headwater streams. To conserve this indigenous species, it is necessary to characterize its habitat preferences.2. Seven brooks in the Deux-Se`vres De´partement (western France) containing wild populations of A. pallipes were studied to determine its ranges of tolerance to 19 physical and chemical water parameters. On two brooks, the Se`vre Nantaise and the Verdonnie`re, sites with and without A. pallipes were compared. Each site was sampled twice monthly from November 2002 to November 2004.3. It was found that the white-clawed crayfish was able to tolerate wide ranges of values of some of the measured parameters. The Magot site harboured the largest A. pallipes population (17.5 crayfish m À2 ) and had dissolved oxygen concentrations as low as 4.93 mg L À1 , while water temperature rose above 208C for several consecutive days during summer and nitrate concentrations were always found to be above 30 mg L À1. These unusual findings could call into question the status of A. pallipes as a bioindicator of good water quality.4. Principal component analyses (PCA) suggested that an increase of organic matter was a discriminant factor for the presence or absence of A. pallipes. In addition, sites with and without crayfish on the Se`vre Nantaise brook showed showed significant differences (p50:05) in total organic carbon (TOC), and those on the Verdonnie`re brook in turbidity and total suspended solids (TSS).

Estimating age composition in Alpine native populations of Austropotamobius pallipes complex

“…This decline is due to causes frequently linked to direct human action, such as habitat fragmentation, deforestation and water deterioration (Nardi et al, 2005;Trouilhe et al, 2007;Favaro et al, 2010). Consequently, the species is listed in the EU Directive 92/43/EEC, commonly known as Habitat Directive (Annex II and V) and it is also listed as endangered by the IUCN (Füreder et al, 2010).…”

Water chemistry and endangered white-clawed Crayfish: a literature review and field study of water chemistry association inAustropotamobius pallipes

“…Populations of A. pallipes have been found in water with potassium concentrations similar to those of mean global and European waters (Figure 1d) with two studies finding populations associated with concentrations in the lower ranges of global and European means (Rallo and Garcia-Arberas, 2002;Trouilhé et al, 2007). Given the wide range of potassium concentrations found in waters inhabited by A. pallipes, no association for specific potassium concentrations can be identified.…”

“…However, several studies (e.g. Trouilhé et al, 2007) also found populations to persist at concentrations lower than the means cited for European rivers. It appears that there may be a lower threshold for dissolved oxygen concentration below which crayfish are not found (i.e.…”

Towards a sustainable human use of freshwater crayfish (Crustacea, Decapoda, Astacidea)

“…Demers and Reynolds (2002), for example, has shown that, in Ireland, A. pallipes can be found in moderately polluted waters. More recently, Trouilhé et al (2007) found that in France this species is able to tolerate wide ranges in the value of some physico-chemical water parameters: the site that harbored the largest A. pallipes population of the study (17.5 crayfish·m −2 ) had dissolved oxygen concentrations as low as 4.93 mg·L −1 , while water temperature rose above 20 • C for several consecutive days during summer and nitrate concentrations were always found to be above 30 mg·L −1 .…”