Our native fish species are being put at risk by an unlikely source as one man found to his cost at Reading Magistrates’ Court today.

On Wednesday 13 December Derek May, of Westwood Glen, Reading, Berkshire, found himself in the dock after illegally disposing of his goldfish in the River Thames.

The court heard that Mr May was left with between 15 and 20 goldfish that didn’t turn gold but stayed a dark colour in his garden pond. Instead of disposing of the fish responsibly, Mr May ditched the goldfish into the River Thames at Scours Lane, Reading, on 29 March 2006.

A member of the public reported Mr May to the the Environment Agency after seeing him empty a bucket of goldfish into the river. The Environment Agency joined Thames Valley Police to investigate the incident. By releasing the goldfish, Carassius auratus, into the river Mr May had broken two laws:

· Section 14 of the Wildlife and Countryside Act – Releasing an animal into the wild that is not normally resident.
· Section 30 of the Salmon and Freshwater Fishery Act – Introducing fish into a water course without a valid consent from the Environment Agency.

Although harmless in a fish tank or garden pond, goldfish, which were originally brought to the UK from Asia in the 1600s, can have a detrimental affect on the native fish species of our rivers and lakes.

Released into the wild goldfish can grow in size and numbers and have been known to mate with wild crucian carp, Carassius carassius, creating a hybrid species. This interbreeding threatens the native population of pure crucian carp.

Non-native fish species threaten to dominate our rivers, lakes and streams, in a similar way that American signal crayfish have decimated populations of our native crayfish, and like the grey squirrel has done to the native red in our forests.

Goldfish can also carry diseases and parasites that are not normally present in wild fish populations. Our native species have not developed an immunity to fight new diseases, and any introduction of disease into wild populations can lead to significant fish deaths. One such disease is Koi Herpesvirus, a highly pathogenic disease that affects common carp, ghost carp and Koi carp.

Mr May pleaded guilty at Reading magistrates and was given a six-month conditional discharge and ordered to pay £60 in costs. If Mr May commits a similar offence within this time he can be sentenced on both the original and the new charge.

Dennis Welling, an Environment Agency environmental crime officer, said: “Although some people may think this is a harmless act, introducing non-native fish into the wild can have serious implications for our native fish populations. They carry disease, out-compete native species, and breed so prolifically that they change the natural balance of the ecosystem.”
 
PC Russell Hounslow, from the Thames Valley Police Wildlife Crime Unit, said: “We work with lots of different agencies and this is another good example of that partnership at work.

“Although this prosecution may seem trivial to some, this incident could have had traumatic implications for the environment.”

Earlier this year the Environment Agency released a list of the top 10 most wanted invasive species in our environment. This included Japenese Hogweed and the American Crayfish, which are growing aggressively in the environment and putting populations of native species under real pressure.

Dennis added: “Although the humble goldfish has been part of our society for 400 years, it is still a non-native species that should be enjoyed in garden ponds and fish tanks, rather than damaging native fish stocks in our lakes, streams and rivers.”

“Where the evidence is available we will support our police colleagues in prosecuting those who fail to protect our environment for future generations.”

The Environment Agency has a statutory duty to maintain, improve and develop fisheries using its regulatory powers but also works to ensure all waters in England and Wales are capable of sustaining thriving fish populations.

To report an environmental crime the public can call the Environment Agency’s 24-hour hotline on 0800 807060.