Algae bloom kills fish at Thatcham beauty spot
Full review to try and prevent fish kill repeat
A THATCHAM beauty spot fell victim to the hot weather last week after an algae bloom killed hundreds of fish.
Dead fish were seen floating in the lake around the popular Nature Discovery Centre, while opportunistic birds swooped to pick off the carcasses. A bad smell was also reported coming from the water.
Now the Environment Agency and centre manager the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust (BBOWT) have launched a review to try and prevent it happening again.
Jackie Field contacted the Newbury Weekly News to say that fish were gasping for air at the surface and being left to die.
She said: “This morning [Friday] it stinks down there, fish dead on the surface and around the edges and sea gulls swarming around – not very good for the bank holiday weekend and children playing around the area.
“We reported it to the Environment Agency but they were not particularly bothered about putting pumps in to give the fish oxygen to help them overnight.”
Resident Leigh Bremner said that there was a horrid smell around the lake at the weekend.
Officials are saying that the algae bloom is a natural process and that last week’s scorching summer temperatures, combined with nutrient levels in the lake, created the perfect growing conditions for the organism.
As algae grows, it reduces oxygen levels in the water; leaving fish and other aquatic wildlife struggling to breathe.
Staff from BBOWT, which manages the centre on behalf of West Berkshire Council, said that workers have been removing dead fish since they were first observed on Friday.
BBOWT confirmed that all dead fish were removed from the site on Tuesday, which it hoped would reduce the unpleasant smell.
Discovery centre manager Liz Shearer said that the Environment Agency (EA) had been notified of the algae when it first appeared in June.
“It’s a totally natural process,” Mrs Shearer said, adding that the bloom had reached its peak because of last week’s high temperatures.
She advised people not to touch crayfish seen coming out of the lake and for people to keep themselves and pets out of the water.
Signs warning people about the algae have been placed around the lake.
“Keep out of the water as it can make dogs and children quite poorly,” Mrs Shearer said. “The only thing that we can bring home to people is to keep animals and themselves out of the water.”
BBOWT apologised for any distress caused and said that maintaining safety and access for visitors had been its priority.
The trust said that the number of dead fish had significantly reduced since the algal peak on Sunday and anticipated that the bloom would have little effect on long-term fish numbers.
BBOWT and the EA had discussed options to help reoxygenate the water at the weekend and save the fish but none were deemed suitable.
It said a pump could have sped up the decomposition of the algal bloom; releasing more natural toxins and further reducing oxygen levels.
Cooler temperatures are expected to restore oxygen levels in the coming days.
“In the meantime, daily monitoring of conditions will continue, and BBOWT will carry out a full review to establish if any further action can be taken to help avoid similar occurrences in the future,” the trust said.
An EA spokeswoman, Auria Dee, said staff have been on site monitoring the situation and advising the discovery centre staff since the bloom was reported.
She said that the bloom did not necessarily indicate poor water quality; rather a degree of nutrient enrichment in the water, which can be due to a number of factors, including waterfowl and land run-off.
“There is no quick fix for an algal bloom. Proactive management of the nutrients going into the water would be necessary if there was a chronic algal issue,” she said.