The white-clawed crayfish,austropotamobius pallipes, in Great Britain and Ireland with particular reference to its conservation in Great Britain

Abstract

Great Britain and Ireland still contain some of the best stocks of Austropotamobius pallipes in Europe despite the fact that since the early 1980s many populations have been devastated by the effects of crayfish plague and compétitive exclusion by non-native crayfish. Austropotamobiuspallipes is the only crayfish native to Great Britain and Ireland but in récent years a number of introductions of foreign crayfish have been made into Great Britain, for aquacultural, culinary and aquarist purposes. This has resulted in four non-native crayfish species becoming established in thewild, wheretwo, Pacifastacus leniusculus and Astacusleptodactylus, have formed large, harvestable populations, particularly in southern England.Although A. pallipes in Great Britain and Ireland is protected by national and European législation, this has not been enough to protect it from crayfish plague and, in Great Britain, from non-native crayfish. In an attempt to protect A. pallipes even further, législation has been implemented in England, Scotland and Wales which bans the keeping of ail non-native crayfish, except wherethey are being prepared for human consumption. P. leniusculus is, however, exempt from this ban in certain parts of southern Great Britain dueto its high prépondérance on crayfish farms and in the wild. Ireland already bans the introduction of non-native crayfish.It is hoped that the new législation, plus the heightened profile which A. pallipes has recently been given in Great Britain, will ensure its future survival. Key-words :Austropotamobius pallipes, Pacifastacus leniusculus, Astacus leptodactylus, crayfish piague, conservation, législation. Bien que A pallipes soit protégée en Grande-Bretagne et en Irlande par une législation nationale et européenne, ce n'est pas suffisant pour la protéger de la peste et, en Grande-Bretagne, des écrevisses exotiques. Dans le but de protéger encore mieux A. pallipes, une législation a été appliquée en Angleterre, en Ecosse et au Pays de Galles en interdisant de garder les écrevisses exotiques, sauf si elles ont été préparées pour la consommation. Cependant, P. leniusculus échappe à cette interdiction dans certaines parties du sud de la Grande-Bretagne à cause de sa grande prépondérance dans les astacicultures et dans la nature. « L'Irlande vient juste d'interdire l'introduction d'écrevisses exotiques. L'ÉCREVISSE À PATTES BLANCHES, AUSTROPOTAMOBIUS PALLIPES, EN GRANDE-BRETAGNE ET EN IRLANDE ET LES PROBLÈMESNous pouvons espérer que la nouvelle législation en vigueur ainsi que les efforts de sensibilisation pour A pallipes favoriseront sa survie dans le futur.

Mitochondrial and Microsatellite Dna Analyses of Austropotamobius Pallipes Populations in South Tyrol (Italy) and Tyrol (Austria)

“…Populations of the white-clawed crayfish, Austropotamobius pallipes, have declined by 25-50% over the last 25 years (BERNARDO, ILHEU and COSTA, 1997;GHERARDI, SOUTY-GROSSET and REYNOLDS et al, 2003;HOLDICH and ROGERS, 1997;SOUTY-GROSSET, GRANDJEAN and GOUIN, 2003) and a similar trend for this species can also be observed in the northern Italian province of South Tyrol (Autonomous Province of Bozen/Bolzano). According to historical records the autochthonous species A. pallipes was once widely distributed in several areas of the region.…”

Origin and colonization history of the white-clawed crayfish, Austropotamobius pallipes, in Ireland

“…As described by Hewitt (1996) for postglacial colonization, successive bottlenecks during a colonization process lead to the loss of genetic diversity in newly founded populations. Since populations belonging to the Nore drainage displayed the greatest intrapopulational variability and are close to the southern limit of A. pallipes distribution in Ireland (Holdich and Rogers, 1997;Reynolds, 1998), we may suggest that the first populations of white-clawed crayfish were founded in the south of this country and that colonization occurred from the south to the north.…”

Distribution of Crayfish in Europe and Some Adjoining Countries

“…Although the range of A. pallipes has been reduced somewhat by the advent of crayfish plague in the 1980s (ALDERMAN, 1996) it still has a widespread distribution in England, Ireland and Wales HOLDICH and ROGERS, 1997;REYNOLDS, 1997), and some populations are very dense. It occupies a wide range of lacustrine and riverine habitats, particularly in areas of easily-weathered rocks, where the calcium levels are relatively high.…”

“…Pacifastacus leniusculus and A. leptodactylus are now very widespread in England, overlapping with the range of A. pallipes (HOLDICH and REEVE, 1991;HOLDICH et al, 1995HOLDICH et al, , 1999bHOLDICH and ROGERS, 1997). Pacifastacus leniusculus was introduced for aquacultural purposes in the 1970s and has since escaped or been introduced into hundreds of wild sites.…”