Stream Clearance and Crayfish

See 1st and 2nd Jan blips and this is same area, but in need of clearance as a bit of subsidence and massive growth. Weeds were piled up on bridge ready for cremation. A crayfish was spotted making me glad I had the wellies on, even though they were full of water. The water course has changed and is now deeper in what were shallow parts. Tricky getting the boots off as the water caused too much suction and there is not much room in my boots anyway. No idea whether the crayfish was British or American any special identification marks I should look out for?