River Nar at Blackborough heavily infested with Signal Crayfish. Interesting how much they vary in colour - some with blue claws, some red.
#signalcrayfish #AlienInvasive #Invasive #NonNative #InvasiveSpecies #crustacean #RiverNar #Wormegay #Norfolk #chalkstreams #KingsLynn 2/7

A🧵on 1st swim in Gaywood River. At request of @RussellB1ggs, had #MySwim at Reffley, then upstream at Derby Fen to clean off. Came biosecure in brand new wetsuits as river maybe Signal Crayfish free. But met another #AlienInvasive, Chinese Mitten Crabs alive & many dead.
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Release of Pheasants in the UK as per letter in @BirdwatchExtra was covered by @MarkAvery on his blog http://markavery.info/2012/08/02/pheasants/ #alieninvasive