PROTECTING & IMPROVING THE TAY
EFFECTS OF SIGNAL CRAYFISH SPREAD
American signal crayfish are established in at least four open watercourses within the district, the Shee, the upper Earn, the Dighty Water and an Eden tributary. They may have spread further. No one is systematically monitoring them nor using this one-off opportunity to establish what impact they may have on juvenile salmon (the impact is to some extent speculative it seems). Neither does there appear to be any proven method of really stopping their spread in larger watercourses.
The Board is developing a programme to establish their approximate extent of spread and to obtain baseline data on juvenile salmon numbers in areas that in danger of being overrun.