Do culverts impact the movements of the endangered white-clawed crayfish?

Abstract

Key-words: crayfish, dispersal, tracking, Austropotamobius pallipes, impoundmentCulverts can impact the migration and dispersal of aquatic animals and result in population fragmentation, increasing the risk of local extinction for endangered species such as the white-clawed crayfish Austropotamobius pallipes. This study used radio telemetry and passive integrated transponder (PIT) telemetry to determine whether existing and experimental covered culverts affect the upstream and downstream movements of adult white-clawed crayfish. Daily crayfish movement rates did not differ significantly between an unlit 363-m long culvert and open stream channel sections. Crayfish moved into dark, covered sections volitionally. However, limited upstream movement occurred at sudden transitions of bed height or smooth-concrete box culvert sections with fast flow, suggesting partial barrier effects. In the 20-m long experimental in-stream culvert, also dark, but with natural stream bed, 70% of radio-tagged crayfish released downstream entered the culvert, as did 60% of those released upstream. Overall 35% passed through, with similar numbers in each direction. We conclude that dark culverts up to several hundred metres do not inhibit dispersal of white-clawed crayfish, provided stream slope, bed type and water velocity are amenable for movement and refuge. Care is required to ensure that culverts are bioengineered to ensure that average water velocity is sufficiently low and local hydraulic variation high, the bed and/or sidewalls contain refuge structures, and there are no cross-channel steps in bed level. Smooth-bedded box culverts are unlikely to be suitable for white-clawed crayfish. RÉSUMÉLes ponceaux influent-ils sur les mouvements de l'écrevisse à pattes blanches en voie de disparition ? Mots-clés :écrevisse, dispersion, suivi télémétrique, Les petits ponts d'une seule travée peuvent influer sur la migration et la dispersion des animaux aquatiques et entraîner la fragmentation de la population, augmentant le risque d'extinction locale des espèces menacées telles que l'écrevisse à pattes blanches, Austropotamobius pallipes. Cette étude a utilisé la télémétrie radio et la télémétrie par transpondeur passif intégré (PIT) afin de déterminer si les ponceaux couverts existants et expérimentaux affectent les mouvements en

Forestry Best Management Practices Relationships with Aquatic and Riparian Fauna: A Review

“…However, application of BMP technology at stream crossings can help substrate heterogeneity and stream flow regimes, and retain streambank integrity [72,[76][77][78], all of which are important environmental characteristics for maintaining and conserving healthy aquatic and terrestrial riparian wildlife [71,79].…”

“…Some designs, such as open-bottom culverts, can mimic natural channel shape and substrate and preserve natural hydrological attributes [76][77][78]83]. Although research on the effects of stream crossings on riparian and aquatic wildlife other than fish [86,87] are relatively limited [71,77,78], culvert BMPs and culvert design have been shown to influence mussels [88], crayfish [77,78], snails [89][90][91][92], and aquatic insects [93][94][95][96]. The complexity of culvert material, design, and placement and potential effects on a variety of aquatic organisms warrants further investigation.…”

The long-term effects and detection ranges of passive integrated transponders in white-clawed crayfish Austropotamobius pallipes

“…The standard marking techniques for tracking crayfish have historically included cauterization, hole-punching, marking with correction fluid or oil-based pens/paints and radio-tracking (Abrahamssons, 1965;Guan, 1997;Robinson et al, 2000;Haddaway et al, 2010;Ramalho et al, 2010;Louca et al, 2014). However, none of these methods provides a permanent method of marking that is retained during moulting and some methods, such as cauterization, have been shown to reduce growth rates (Guan, 1997).…”

“…In recent years, this technique has been used on crayfish species and there have been several in situ and ex situ studies published. Field experiments include studies on A. pallipes (Bubb et al, 2008;Louca et al, 2014;Stead et al, 2015), slender crayfish Orconectes compressus, (Black et al, 2010), giant Tasmanian crayfish Astacopsis gouldi (Shepherd et al, 2011) and signal crayfish Pascifastacus leniusclus (Stead et al, 2015). Laboratory experiments include studies on P. leniusclus (Wiles and Guan, 1993;Bubb et al, 2002), spiny-cheek crayfish Orconectes limosus (Buřič et al, 2008), O. compressus (Black et al, 2010), and woodland crayfish Orconectes hylas (Westhoff and Sievert, 2013).…”

“…There are a few published field studies, which have shown that PIT-tagged A. pallipes survived when returned to the wild (Bubb et al, 2010;Louca et al, 2014;Stead et al, 2015). However, in all of these studies, only a proportion of the released tagged crayfish were detected and therefore percentage survival and growth of A. pallipes, post-tagging, could not be confirmed.…”