Fish perish as Canvey Lake turns ‘toxic’

Canvey Lake on Canvey Island has become so toxic that people are being told to keep their pets away from the watercourse and dead fish are seen floating on its surface.

This year’s extended period of dry, warm weather, in conjunction with an accumulation of tonnes of silt built up over the 40 years since the lake was built as a flood defence mechanism, has left Canvey Lake so deprived of oxygen that it is showing the tell tale signs of being ecologically stressed with scores of dead fish floating on the surface alongside an algal bloom.

Resident Rob Turner, who has set up a crowdfunder to help save the ecological viability of the lake – which was created as a water holding facility and the repository for water taken from the storm drains – has put two aerators in the water paid for with around £11,000 crowdfunded from residents.

He has allocated a further chunk of funding to clearing up the dead fish and birds.

But he says the long term solution has to be to dredge out silt that has reduced the capacity of the lake by about 80 per cent – to only about a foot of water in places.

It means there is now about five feet of silt leaving just a foot of water.

This low water level has led to the deaths of significant numbers of fish which in turn has led to a spike in bacteria as they decompose. Disease has now spread killing resident waterfowl.

The number of dead animals, along with an algal bloom, has led to the lake’s leaseholder Canvey Town Council to issue a warning to stay away due to the risk to public health.

Mr Turner, who runs Kings Park Village in Canvey, says it is now imperative the issue is resolved – not just for a public health perspective but to ensure there is enough capacity in the lake to mitigate flooding risks.

As a temporary measure he has raised enough money from public donations to install two aerators, but he admits that represents just a temporary solution.

He said: “Where we had six feet of water where the fish are quite happy, we now have around a foot of water and five feet of silt.

“It represents two issues – from a flood defence point of view if there was a sudden surge I don’t think that system will work. It will fail, there is nowhere for the water to go. It has lost about 5/6 of its capacity. It needs dredging.

“The second problem is the fish have lost 5/6 of their living space and the quality of the water is bad. There has been a algae bloom, a oxygen crash and that has caused the fish to die which in turn has put more bad bacteria into the water.

“It’s become toxic That water is full of bacteria that can cause very serious problems. It’s a health hazard for humans, pets and fish and wildlife. It is a significant problem.”

He said the aerators seem to have stopped the fish dying but now it is up to the Environment Agency to address how to dredge the lake to avoid flooding.

He said any surplus funds from his crowdfunding would be either passed over to an independent group formed by the local community to address issues with the lake in the long term or donated to a charity of residents’ choosing.

He suggest as alternative to dredging the whole lake that 10 per cent from either end should be done as as minimum.
He added: “We are not tackling the flood defence issue but at least we are tackling the wildlife issue – the fish will have a deep pool to swim in and be able to take refuge in the warm weather.

“Everyone is pointing back now to the Environment Agency for them to come in to deal with it from a flood defence perspective which I think is the wider issue – it will be interesting to see if this winter we have a lot of flooding and people’s houses get flooded.

“This has got to be addressed – from a wildlife perspective and also from a flood perspective. At the moment it is complete failure.”

The health issue has been recognised by the town council which has asked people to stay away from the water.

A notice on August 17 from the town council said: “Due to the potential risk to health please do not enter the water or handle any animal carcasses. Please keep any pets away from the watercourse.

“The town council will continue to remove the deceased animals from the lake daily. We foresee this will be an ongoing task for the next seven to 10 days due to the constantly emerging fish and we urge people not to touch any of the fish or wildfowl.”

This follows a message the day before which has explained how the low water level has exacerbated the poor water quality.

A statement on August 16 said that Canvey Island Town Council has been working closely with multiple organisations, including the Environment Agency, DEFRA and the Centre for Environment, Fisheries and Aquaculture Science.

It adds the removal of the silt has previously been investigated both in 2012 and lastly in 2017 by a multi-agency group run by Castle Point Borough Council but given the high costs of dredging that would have to be repeated anyway due to the nature of the lake it was not deemed a viable option.

It added: “It is distressing to see the effect this has had to the fish and wildfowl and whilst we do have contractors there daily to remove the deceased animals, we are battling with the constantly emerging numbers which are due to the dead animals inflating with gases and rising to the surface.

“The animals that are removed must be disposed of by an approved method for disposal of Category 2 animal-by-product waste to ensure it complies with local Environmental Health department regulations.”

Just above one per cent of the amount of council tax each household pays is received by the town council, this equates to £21.87 annually for a Band D property.

From this money the Town Council allocates nearly 15 per cent (£38,220) to the maintenance and running of Canvey Lake. In this financial year the Town Council have already allocated £31,515 to the maintenance of Canvey Lake.

It adds: “The town council will continue to work on the issues faced daily and is endeavouring to find a long-term resolution.

“The town council are thankful for the strong community spirit that has once again been displayed by the residents of Canvey Island and hope that Canvey Lake will be able to return to the wildlife facility we are so fortunate to have in an urban area.”

The Environment Agency has been approached for comment.

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Piers Meyler

Local Democracy Reporter