Invasive crayfish surveys in two local lakes.

We've been busy for the past two weeks undertaking surveys of signal crayfish (Pacifastacus leniusculus) at a couple of local lakes.

Using a combination of fyke nets and baited traps set over three consecutive nights in each lake, we were able to build up a comprehensive picture of the population status, including spatial distribution, depth distribution, size structure and sex ratio.

Setting a baited crayfish trap in a chain of 10 perpendicular to the shoreline.

Baited traps were set in chains of 10 on a 100 m long sinking rope laid from the shoreline perpendicular into deeper water, and fyke nets were set around the perimeter of each lake.