Management of the White-Clawed Crayfish (Austropotamobius Pallipes) in Western France: Abiotic and Biotic Factors Study

Abstract

In France, the distribution of the white-clawed crayfish, Austropotamobius pallipes (Lereboullet, 1858), is restricted, fragmented and mainly located in headwaters. To preserve this indigenous species, it is necessary to characterize its ecological requirements (water and habitat quality). With this aim in view, a two-year study is being conducted in the Deux-Sèvres department (Western France) since November 2002. Nine brooks from four different catchments are monitored regularly; eight of the nine brooks harbour whiteclawed crayfish populations. Two sampling sites are surveyed per brook, the first being where the crayfish population is located and the second 2 to 3 km downstream. Physicochemical parameters (18) are measured twice monthly and biotic factors are estimated twice yearly. In this study, the I.B.G.N. (Indice Biologique Global Normalisé) protocol based on the determination of macroinvertebrates was used as a biotic index of biological water quality. Results of this preliminary study on two brooks (Thouet and Verdonnière) show that physico-chemical and biological data considered separately do not provide reliable information about A. pallipes ecological requirements. However, the use of multivariate analyses (Principal Component Analysis) to combine abiotic and biotic factors highlights a good correlation between these parameters. Organic matter appears to be a better discriminating factor than mineral matter affecting presence or absence of the whiteclawed crayfish. Key-words:Austropotamobius pallipes, water quality, biotic index, macroinvertebrates, Principal Component Analysis (PCA). GESTION DE L'ÉCREVISSE À PATTES BLANCHES (AUSTROPOTAMOBIUS PALLIPES) DANS L'OUEST DE LA FRANCE : ÉTUDE DES FACTEURS BIOTIQUES ET ABIOTIQUES RésuméEn France, la distribution de l'écrevisse à pattes blanches, Austropotamobius pallipes (Lereboullet, 1858), est réduite, fragmentée et principalement située en tête de bassin. Afin de préserver cette espèce indigène, il est nécessaire de caractériser ses exigences écologiques (qualité de l'eau et de l'habitat). Dans ce but, une étude de deux ans est menée dans le département des Deux-Sèvres (Ouest de la France) depuis novembre 2002. Neuf ruisseaux sur quatre bassins hydrographiques différents sont régulièrement visités. Deux sites de prélèvements par ruisseau sont prospectés, le premier site est localisé au niveau de la population d'écrevisses et le second 2 à 3 km en aval. Les paramètres physico-chimiques (18) sont mesurés deux fois par mois et des facteurs biotiques sont estimés bi-annuellement. Dans cette étude, le protocole de l'I.B.G.N. (Indice Biologique Global Normalisé) basé sur la détermination de macroinvertébrés a été utilisé comme facteur biotique pour estimer la qualité biologique de l'eau. Les résultats de cette étude préliminaire sur deux ruisseaux (Thouet et Verdonnière) montrent que les données physico-chimiques et biologiques prises séparément ne fournissent pas d'informations fiables quant aux exigences écologiques d'A. pallipes. Cependant, l'utilis...

Feeding habits of the crayfishAustropotamobius pallipes(Decapoda, Astacidae) in a brook in Latium (central Italy)

“…Gherardi et al 1996;Grandjean et al 1998Grandjean et al , 2000Grandjean et al , 2003Largiarder et al 2000;Demers et al 2003;Trouilhe et al 2003;Fratini et al 2005). This provides enough information to preserve this species in situ.…”

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

“…Three notable exceptions relative to European rivers have been documented, however. Broquet et al (2002), Trouilhé et al (2003) and Trouilhé et al (2007) have reported some French populations of A. pallipes to inhabit waters with substantially higher nitrate concentrations than other authors. Our field survey found a range of nitrate concentrations in waters inhabited by A. pallipes very similar to those of European rivers.…”

“…Others, for example Broquet et al (2002), noted crayfish in higher concentrations than the range of European means, but with values that fell within the range of global means. It has been suggested that a lower limit of 5 mg·L −1 calcium concentration restricts the presence of A. pallipes (Greenaway, 1974), as supported by observations of Jay and Holdich (1981) and Smith et al (1996) (Reyjol and Roqueplo, 2002) and one as low as 1 mg·L −1 (Trouilhé et al, 2003). Crayfish can, therefore, evidently survive below the proposed 5 mg·L −1 threshold.…”

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

“…Indeed, several studies have shown that habitat heterogeneity, water quality and lack of pollutants enhance or ensure the survival of some indigenous species (e.g. Trouilhé et al, 2003). Often, the decline or the extinction of indigenous crayfish has been observed in areas with extensive land use, crayfish being highly sensitive to a great variety of fertilizers, insecticides and pesticides (Eversole et al, 1995).…”