Following up on a report by a local angling club, that an American Signal Crayfish (ASC) had been seen in a local river, we obtained the necessary licences to commence trapping in an attempt to confirm the sighting. At the moment, we won’t confirm the river or the location but can confirm that the River affected is in the Ayr catchment.
Unfortunately, after a single night’s trapping (under licences issued by Marine Scotland Science and SNH), we can now confirm that ASC are present in Ayrshire and this, apart from being very disappointing is potentially highly damaging to native fish populations in this river and downstream. All the relevant authorities have been notified and we will prepare a full statement on this in due course but felt it important to alert anglers to their presence immediately to prevent further spread. It is illegal to trap these creatures without a Government issued license and anyone caught doing so will be reported to the Procurator Fiscal by the DSFB bailiffs or Police Scotland. Don’t be tempted to try this as there’s a risk that you may spread them further causing even more damage. Catching and eating trap caught crayfish in Scotland is illegal.
The local angling club are aware of our findings and are extremely concerned. How they got there is unknown and we won’t speculate further at present but there’s no doubt that this has been a deliberate and reckless act.
Moving live ASC is illegal, a wildlife crime and highly irresponsible. They cause damage to fish and invertebrate populations, destroy habitat and will downgrade a system due to them being an invasive non native species. Wherever possible, anyone caught introducing these or invasive species will be prosecuted under the Wildlife and Natural Environment (Scotland) Act 2011.
To prevent the accidental spread of these and other non native species, anglers and river users are encouraged to follow a few simple biosecurity measures:
Check – once you are ready to leave a fishing spot, always check your equipment for any non native species (plant or animal). Pay particular attention to nets where crayfish could be trapped in the folds.
Clean – before you leave the riverbank, clean any equipment at the water’s edge, removing mud, plant material from equipment and boots. Once at home, disinfect any equipment that’s been in contact with the water using a proprietary product such as Virkon.
Dry – following cleaning and drying, thoroughly dry all equipment before reuse. Most aquatic organisms won’t survive long out of water so this is especially important.
Anyone finding what they believe to be an American Signal Crayfish in Ayrshire should immediately kill it by a firm stamp on it’s head and body. This is a legal requirement as it is an offence to release it (accidentally or deliberately) and is the recognised method of dispatch in this situation. Photograph the the body or better still bag it and then contact the Trust immediately or SEPA. We will then notify the necessary authorities. In this instance, we commend the angling club for quickly alerting us to the report and we will provide as much support and information on this species as possible to help their members prevent the spread further.
Sadly once these crayfish become obvious, it is usually too late to get rid of them and in any case, in anything but a very small burn or stank/pond, eradication has never been achieved successful yet.
This thoughtless act will deplete stocks of trout and salmon and other native fish for centuries to come unless someone develops an acceptable method of control. There has been limited work done to develop a suitable method but as yet, there’s really nothing we can do to get rid of them.