Discovery of 'killer' shrimp alarms experts

For the first time the vicious shrimp
Dikerogammarus villosus has been found in Britain, causing consternation among scientists charged with keeping the country's waterways stocked with native wildlife.

Visually, the brown crustacean may not inspire in the public the terror generated by more fearsome monsters of the deep, but a hint of the menace scientists say it is capable of can be gleaned from its nickname: the killer shrimp.

A particularly voracious and aggressive predator, Dikerogammarus villosus preys on a range of invertebrates, particularly native shrimps and young fish, sometimes causing their extinction. It tends to dominate its habitat, killing and maiming unselectively.

Its aggression – it bites and shreds its prey to death but often leaves it uneaten – is matched by its versatility, and it can survive fluctuations in temperature, salinity and oxygen levels. As a result its numbers have grown rapidly in the long rivers of western Europe in the past 20 years, damaging smaller species and ruining ecological chains.

On Friday two anglers spotted unusual-looking shrimps scuttling along Grafham Water reservoir in Cambridgeshire, captured some specimens and sent them to the Environment Agency.

A preliminary identification of Dikerogammarus villosus was made – later confirmed by a Dutch scientist – prompting a full-scale alert. The agency contacted Anglian Water, the owner of Grafham, and began measures to survey and halt the shrimp's presence.

Expert biologists have begun testing the water flowing into and out of Grafham, which will indicate the severity of the problem and what measures need to be taken. Signs have also been erected asking anglers, boaters and other water users to look out for the shrimp and to scrub their rods, boats and other apparatus to ensure they do not carry it unwittingly into other water.

Dr Paul Leinster, the Environment Agency's chief executive, said: "We are devastated that this shrimp has been found in Britain, and very grateful to the keen-eyed anglers who found it.

"We are currently establishing the degree of the problem, and whether the shrimp is only in Grafham Water or if it is in nearby lakes and the Great Ouse as well."

Scientists will have to look closely because the shrimp is small, ranging from 3mm to 30mm. Despite its small size, if the shrimp becomes established in Britain, the Environment Agency fears it could soon start swallowing natives species common on lakes and rivers, such as native damselflies and water boatmen, with knock-on effects on the species which feed on them – birds, spiders and frogs.

Ciaran Nelson, from Anglian Water, said: "We have put precautionary biosecurity measures in place around Grafham Water as containing the shrimp is of paramount importance. We are also assisting with investigations to establish if it is already more widespread. The presence of this species poses no risk to the quality of drinking water supplies.

"We are asking all water users at Grafham to take the actions asked of them on-site. This includes checking equipment for shrimp when they leave the water and removing any they find. They should also ensure equipment is thoroughly cleaned and dried before it is put into any other water. Subject to these controls, recreational activities on the reservoir can continue."

The Environment Agency said the shrimp could have arrived at Grafham in various ways, for example through boating, angling, fish-stocking – or naturally, via birds. Its progress through western Europe has been rapid. Populations in the Black Sea rivers had spread northwards and westwards into the German Danube by 1992, since when it has spread into other German rivers such as the Rhine and Elbe, and the Rhone in France.

Alarm about its arrival has reached the upper echelons of Whitehall. The Environment Minister, Richard Benyon, said he was "extremely concerned" it had been found. "Anglian Water has acted quickly to put biosecurity measures in place and the Environment Agency is working hard to establish the extent of the problem and what action may need to be taken," he said.

"We need to do everything we can to protect our native wildlife and young fish from the potential damage the killer shrimp can cause."

Water users at Grafham who want information on the measures they can take to combat the spread of the shrimp can contact Anglian Water on 08457 919155.

Anyone who has seen "an unusual shrimp" is asked to email a photograph to the Centre for Ecology & Hydrology for identification. The address is: alert_nonnative@ceh.ac.uk

Invasive species...

American signal crayfish

Native to North America, signals carry a disease, crayfish plague, that is deadly to our threatened native white-claw crayfish. Since their introduction to Britain in the Seventies, they are now widespread throughout Europe.

Non-native American mink

Brought to the UK in the 1920s for fur farms. After several escapes it quickly established itself in the English countryside, becoming the main predator of the native water vole (Ratty in The Wind in the Willows), whose numbers have fallen by more than 90 per cent in 50 years, partly because of predation by mink.

Floating pennywort

After being introduced as an aquatic garden plant in the Eighties, this 'water triffid' soon went wild. It grows in huge, dense mattresses that choke waterways, starving the water of light, oxygen and nutrients.

Topmouth gudgeon

It may be less than three inches long, but this invader from Asia preys on the eggs of native fish, breeds fast and spreads disease.

Chinese mitten crabs

This Asian species has made its home in some UK fresh waters, including the Thames. It damages riverbanks by burrowing into them, and out-competes native species.

Suggested Topics
Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Account Manager

£20000 - £35000 per annum: Recruitment Genius: This full service social media ...

Recruitment Genius: Data Analyst - Online Marketing

£24000 - £35000 per annum: Recruitment Genius: We are 'Changemakers in retail'...

Austen Lloyd: Senior Residential Conveyancer

Very Competitive: Austen Lloyd: Senior Conveyancer - South West We are see...

Austen Lloyd: Residential / Commercial Property Solicitor

Excellent Salary: Austen Lloyd: DORSET MARKET TOWN - SENIOR PROPERTY SOLICITOR...

Day In a Page

Isis in Iraq: Yazidi girls killing themselves to escape rape and imprisonment by militants

'Jilan killed herself in the bathroom. She cut her wrists and hanged herself'

Yazidi girls killing themselves to escape rape and imprisonment
Ed Balls interview: 'If I think about the deficit when I'm playing the piano, it all goes wrong'

Ed Balls interview

'If I think about the deficit when I'm playing the piano, it all goes wrong'
He's behind you, dude!

US stars in UK panto

From David Hasselhoff to Jerry Hall
Grace Dent's Christmas Quiz: What are you – a festive curmudgeon or top of the tree?

Grace Dent's Christmas Quiz

What are you – a festive curmudgeon or top of the tree?
Nasa planning to build cloud cities in airships above Venus

Nasa planning to build cloud cities in airships above Venus

Planet’s surface is inhospitable to humans but 30 miles above it is almost perfect
Surrounded by high-rise flats is a little house filled with Lebanon’s history - clocks, rifles, frogmen’s uniforms and colonial helmets

Clocks, rifles, swords, frogmen’s uniforms

Surrounded by high-rise flats is a little house filled with Lebanon’s history
Return to Gaza: Four months on, the wounds left by Israel's bombardment have not yet healed

Four months after the bombardment, Gaza’s wounds are yet to heal

Kim Sengupta is reunited with a man whose plight mirrors the suffering of the Palestinian people
Gastric surgery: Is it really the answer to the UK's obesity epidemic?

Is gastric surgery really the answer to the UK's obesity epidemic?

Critics argue that it’s crazy to operate on healthy people just to stop them eating
Homeless Veterans appeal: Christmas charity auction Part 2 - now LIVE

Homeless Veterans appeal: Christmas charity auction

Bid on original art, or trips of a lifetime to Africa or the 'Corrie' set, and help Homeless Veterans
Pantomime rings the changes to welcome autistic theatre-goers

Autism-friendly theatre

Pantomime leads the pack in quest to welcome all
The week Hollywood got scared and had to grow up a bit

The week Hollywood got scared and had to grow up a bit

Sony suffered a chorus of disapproval after it withdrew 'The Interview', but it's not too late for it to take a stand, says Joan Smith
From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?

Panto dames: before and after

From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?
Thirties murder mystery novel is surprise runaway Christmas hit

Thirties murder mystery novel is surprise runaway Christmas hit

Booksellers say readers are turning away from dark modern thrillers and back to the golden age of crime writing
Anne-Marie Huby: 'Charities deserve the best,' says founder of JustGiving

Anne-Marie Huby: 'Charities deserve the best'

Ten million of us have used the JustGiving website to donate to good causes. Its co-founder says that being dynamic is as important as being kind
The botanist who hunts for giant trees at Kew Gardens

The man who hunts giants

A Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there