Invasive Signal Crayfish found in the Almond Catchment

New population of American signal crayfish found in the Forth District.

We have unfortunately been alerted to a new outbreak of American signal crayfish which was then confirmed by Trust staff. Thank you to the individuals who reported the sighting to us. The new outbreak is within the Almond catchment in West Lothian, a catchment which did not have them previous to our signal crayfish surveys in 2013.

American signal crayfish are non native originating from North America and were introduced in ponds and rivers as ornamental animals.

We would like to remind any river users to remain vigilant if in or around the river and to make sure you follow the check, clean dry protocol to reduce the likelihood of them spreading to other areas.

Unfortunately, once they are in a watercourse, there is no way to remove them as the only sure fire way to get rid of them is poison the full river. This is not an option. Trapping has proved ineffective and can exacerbate the problem as trapping usually only removes the larger crayfish, leaving the smaller ones to thrive. The large crayfish also predate on the smaller crayfish keeping populations in check.

It is illegal to trap or transport American signal crayfish without a license and Nature Scot, SEPA and Police Scotland are aware of their presence.

For more information on American signal crayfish please see the below link.

http://www.nonnativespecies.org/downloadDocument.cfm?id=68

For more information on check, clean dry and good biosecurity practices please see the link below.

http://www.nonnativespecies.org/checkcleandry/index.cfm

If you spot American signal crayfish in a river around the Forth, please let us know by emailing trust@forthriverstrust.org or messaging us via our social media accounts.