About 90kg (200lbs) of dead fish have been removed from a canal after a sodium cyanide leak in Walsall that experts fear could have “devastated the aquatic ecosystem” in the area.

A 1km stretch of the waterway remains closed to the public after the chemical spill from a metal finishing company, Anochrome. The spill was declared a major incident last week.

Walsall council said testing had shown a 300-metre stretch of the canal was affected by the spill and 90kg of fish carcasses were removed from the canal over the weekend.

“There have been significant numbers of fish killed, but the impact on the wider ecology is not yet known,” the council said.

“Chemical testing will continue on a daily basis, and we are monitoring water levels. Although we hope cyanide levels will fall, we are exploring all potential remediation techniques that may be required in the future.”

Temporary dams have been installed on either side of the affected red zone, where high levels of sodium cyanide and zinc cyanide were recorded.

Latest statement from Walsall Council

Reported in The Guardian