Recent posts

Crayfish Count Interview on BBC Radio Wales

Sat, 12/17/2016 - 11:55 -- Chloe Robinson

After writing a newsletter article on citizen science, a representative from BBC Radio Wales contacted me with the opportunity of speaking about my project ‘Crayfish Count’ on their Science Café broadcast.

Signal Crayfish

They wanted this segment to feature citizen science projects which are in progress in and around Wales, stressing it would be a great chance to promote the research I'm doing & the current aquatic research being undertaken at Swansea University. Being interviewed in a radio studio was something I had never done before, but the guys down at the Swansea Studio made the experience thoroughly enjoyable! Adam from BBC Radio Wales rang in to conduct the interview and we spoke about identifying UK crayfish species, current distribution of invasive signal crayfish and what the public can do to get involved with the Crayfish Count.   We also spoke about the collaborations between our research group and angling groups, such as Afan & Merthyr angling club, who have been fantastic in both the Crayfish Count and in collecting river samples for eDNA screening here at Swansea University. 

Overall, the experience was fantastic and I would like thank BBC Radio Wales for the chance to speak about my research and promote citizen science in Wales.

For more information & to listen to the interview, please visit: 

BBC Radio Wales Science Café interview:

NRN-LCEE Citizen Science Newsletter: 

Aquawales Website:

American signal crayfish - Invading a water body near you...

Wed, 04/06/2016 - 19:07 -- Chloe Robinson

What are they?

An invasive (non-native) crayfish species originally from North America; dark brown in appearance with distinctive red underside to claws and blue-white ‘hinge’ on top of claws. They are often found in lakes, ponds and slow-flowing stream and river systems with soft substrate.

Signal Crayfish

How did they get here?

Signal crayfish were extensively farmed in the UK throughout the 1970s to supply the Scandinavian market. Inadequate facilities and lack of escape prevention protocols led to many individuals escaping into the local environment, along with purposeful stocking and release of ‘pet’ signal crayfish. This has resulted in many introduction points across the UK of signal crayfish, which has been one of the factors which led to their success establishing as an invasive species.

What impact are they having?

Signal crayfish are much larger, more aggressive and more fertile than our native white-clawed crayfish (Austropotamobius pallipes) and therefore outcompete them for food and space. Signal crayfish are also carriers of the crayfish plague (Aphanomyces astaci) which does not affect the signals but causes 100% mortality in native crayfish populations. They also trip river banks of aquatic vegetation, destroy river banks through extensive burrowing and prey on fish eggs and juveniles. The UK government spent on average £1 million/year trying to control the spread of this invasive species.

What is being done?

Environmental companies have been using a variety of methods to try and control the spread/eradicate signal crayfish, these include:


-Manual removal of crayfish

-Removal of habitat

-Installing physical barriers to dispersal (i.e. in-channel weirs, dams, screens, catch-pit outfalls, fencing)

-Introduction of predators (e.g. eels, chub)

Despite all the efforts above, signal crayfish populations continue to spread. However, new scientific methods are being developed which will allow scientists to detect signal crayfish presence in the local water body from the DNA they leave behind in the water.  This will allow potentially newly colonised sites to be identified and targeted as areas to focus eradication efforts to prevent further dispersal.

How can you help?

Part of the problem with trying to eradicate signal crayfish is that we do not know exactly where they are – this is where you can help. The AquaInvaders project allows you to record any sightings of signal crayfish (and a large number of other aquatic invasive species) on your smartphone, tablet or via the website. The app is free, very easy to use and is a great way of getting involved with helping your local conservation groups.

VOLUNTEERS REQUIRED: If you would like to get involved or more information on a nationwide citizen science project which involves use of the app to monitor signal crayfish then please send an email to

Quagga Mussel added

Fri, 11/13/2015 - 20:19 -- Dave Kilbey

In the world of invasive species it does seem as if we're constantly waiting for the next big problem to arrive.  Unfortunately as some of you will know Quagga mussel was confirmed for the first time in October 2014 in west London.  Very similar in appearance to its close relative the Zebra mussel you can find some guidance on ID and various briefing notes on the GBNNNS website here.  We've also added it to the species you can record via the AquaInvaders website and it will feature in the next version of the app too.

Quagga Mussel