‘CRAYFISH BOB’ Ring is on a mission – to protect Oxfordshire’s ‘infested’ waterways and wildlife from an American waterborne assassin.

The 57-year-old soon-to-be grandfather from Abingdon, is waging a war against the American Signal Crayfish (ASC) and can regularly be seen out on the Thames, pulling up traps teaming with the clawed critters.

But Crayfish Bob doesn’t want us to just get rid of the renegade crayfish – he wants us to eat them.

ASCs are smaller, but apparently sweeter tasting versions of lobster, and were introduced to our waters in 1976 as a farming business, which promptly went bust, with catastrophic consequences.

Crayfish Bob said: “The Ministry of Agriculture Fisheries and Food (MAFF) brought American Signal Crayfish to this country because of their excellent eating qualities and the belief that farming them would provide extra income for the farmers, and take the pressure off the widespread native white-clawed crayfish, which were then threatened.

“The Government gave grants to encourage estate owners and aquaculturists to engage in the project.”

The ASCs quickly established themselves all over the countryside in such numbers that farming them was uneconomical and Crayfish Bob added: “The waters of Oxfordshire are now infested.” Crayfish carry about 250 eggs incubated on each female, but ASCs often carry the crayfish plague (A.astaci) which kills the native white-clawed species within weeks.

Crayfish Bob, a former artist and photographer, became interested in the crustaceans after attending a festival in the Finish capital Helsinki where people were paying hundred of pounds a head for seats at a crayfish feast.

And he believes we Brits are missing a trick when it comes to dealing with them.

For the past seven years he has been legally trapping up to half a tonne a week from the waters around Abingdon.

He catches all sizes of crayfish using traps with otter guards, safeguarding other wildlife.

He then sells the bigger beasts to Scandinavia, but believes the future in controlling the population lies in encouraging people to eat the “smalls” as well.

Crayfish Bob sells a kilo for between £3 and £12 after setting up ‘Crayaway’ and ‘Crayfish Bob’ products.

Environment Agency fisheries team leader John Sutton said: “Signal crayfish have been present around Oxford for over 20 years.

“We don’t have clear evidence that local trapping of signal crayfish is beneficial to stocks of the native species. “We issue authorisations for trapping of signal crayfish in the Thames for commercial and domestic consumption, and in some cases intensive trapping, to reduce the nuisance impact on anglers.”

  • Members of the species are typically six–nine cm (2.4–3.5 in) long, although sizes up to 16–18 cm (6.3–7.1 in) are possible.

They are bluish-brown to reddish-brown in colour with robust, large, smooth claws.
They have a white to pale blue-green patch near the claw hinge, like the white flags that signalmen used for directing trains – hence the name.
The life cycle of the signal crayfish is typical for the species.
About 200–400 eggs are laid after mating in the autumn, and are carried under the female’s tail until they are ready to hatch the following spring.
The eggs hatch into juveniles, which pass through three moults before leaving their mother.
Sexual maturity is reached after two to three years, and the life span can be up to 20 years