Environment Canterbury was alerted to the contamination after dead eels were discovered at the creek. The nature of the toxin is unknown at this stage but Environment Canterbury is currently investigating to determine the source of the contamination.
Dr Alistair Humphrey Canterbury Medical Officer of Health says Walnut Creek is a popular site for gathering food such as watercress and eels.
"However, people are advised not to eat or drink anything that's come from the creek until the health warning has been lifted," Dr Humphrey says. Animals that show signs of illness after coming into contact with the creek water should be taken to a vet immediately.
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