Thousands of fish, including endangered eels, die as pollution chokes London river

A devastating pollution incident has caused the deaths of "very large numbers" of fish, including critically endangered European eels, in a South London river, sparking an urgent investigation by environmental agencies.

The cause of the ecological disaster remains unknown.

The Environment Agency and Thames Water are currently probing a 3km stretch of the River Pool in Bromley.

Reports of dead fish in Cator Park, Beckenham, on Sunday afternoon (June 28) triggered the initial response, with officers confirming the incident and returning on Monday (June 29) for further investigation.

An Environment Agency email said: “Large numbers of European eels, which is a species of conservation importance, have been killed along with very large numbers of smaller fish such as stickle backs, gudgeon and stone loach. Some large coarse fish, such as chub, roach and dace have also been killed.”

The loss of European eels is particularly concerning, as the species is listed as critically endangered by the International Union for Conservation of Nature.

Its juvenile populations have plummeted by up to 95 per cent since the 1980s.

Once a common sight in the River Thames, where it was caught for traditional dishes like eel pies and jellied eels, its numbers have drastically declined.

The full extent of the environmental damage and the source of the pollution are still under investigation, as authorities work to understand the impact on the local ecosystem.

The affected stretch of the River Pool extends from Cator Park down to the confluence with the River Ravensbourne, covering about 3km downstream.

Presently, the incident has had no impact on public drinking water supplies, but the Environment Agency has advised members of the public and their animals to avoid the affected stretch of the river.

The agency’s environment officers are continuing to monitor water quality, collect samples, and assess the risk of any ongoing fish mortality, while its fisheries team is assessing the extent of the impact on marine life.

Thames Water, which operates the local drainage network, is “urgently investigating” the pollution incident but its cause is yet to be determined.

It has deployed aeration at key locations along the River Pool to increase dissolved oxygen levels and help mitigate further impacts.

A Thames Water spokesperson said: “We are aware of a pollution issue that has affected wildlife in the River Pool and are urgently investigating the cause with the Environment Agency.

“Tests are currently being carried out to determine the source of the pollution. Thames Water takes its responsibilities to monitor and maintain its wastewater network seriously and understands the concerns residents will have.”

Beckenham Town and Copers Cope Councillor, Steven Jefferies, thanked the Environment Agency for acting swiftly to react to the “tragic incident” in Cator Park.

He said: “Beckenham’s rivers play a crucial role in supporting the biodiversity of our area, and bring great benefits to the health and wellbeing of residents living in our community.

“I and other Liberal Democrats on Bromley Council will continue pushing the relevant authorities to ensure our parks and local wildlife get the protection they deserve.”