…By Gift BADEWO for TDPel Media.
After heavy rain, the Environment Agency is investigating a mass fish and eel mortality incident in the Lea Bridge area.
While initial evidence points to low levels of dissolved oxygen in the water, the situation underscores the potential environmental impacts of climate change and urban pollution.
Rain Triggers Fish Mortality: The Scene at Lea Bridge
On Tuesday, June 20, following a downpour, reports of dying aquatic life in the Lea Bridge area prompted the Environment Agency’s fisheries team to respond.
The agency suspects low levels of dissolved oxygen in the river as the cause and has deployed aerators near the bridge to create a safer environment for the aquatic life.
David Ogle, a local resident, reported witnessing “dozens” of dead fish in a specific area south of Lea Bridge, raising concerns about the frequency of such incidents.
Investigating the Cause: Natural Phenomena or Pollution?
According to an Environment Agency spokesperson, preliminary investigations suggest that the high temperatures coupled with the “low atmospheric pressure” caused by the thunderstorms might be the culprits.
Nevertheless, the possibility of other causes, such as pollution, is still being explored.
The agency encourages the public to report any observed instances of distressed fish to their 24/7 incident hotline.
Yesterday’s starkest images were dead fish close to the oxygenators in the River Lea.
Dispiriting for frontline Environment Agency staff when, despite your best efforts, countless fish are killed by stormwater pollution.
We need systemic solutions, not ‘sticking plasters’. pic.twitter.com/yMHgD9rN7ZAdvertisement
— London Waterkeeper (@LDNWaterkeeper) June 22, 2023
An Alternate Hypothesis: The Role of Urban Pollution
Theo Thomas, founder of the London branch of the Waterkeeper campaign group, presents an alternative theory.
He suggests that accumulated “detritus” on London’s streets and other hard surfaces might have been washed into the river due to the rain, leading to decreased sunlight penetration and bacterial bloom that depleted oxygen levels.
Data monitoring shows a correlation between reduced oxygen levels and increased water turbidity during the rainfall.
Impact of Urbanization: River Health Under Threat
Thomas further asserts that the River Lea is continually threatened each summer due to the runoff of “industrial amounts” of pollution from the roads.
He expresses concern over London’s extensive paving, which prevents the natural filtration and slowdown of runoff water.
Other factors such as high nutrient levels, possibly linked to effluent release from Deephams Sewage Works in Edmonton, leading to excessive growth of green duckweed, further exacerbate the situation.