Freshwater stream's dying crayfish

Wednesday, 21 December 2016

Erin Hampson-Tindale took this footage of what he says were 'thousands' of dead and dying koura floating down a stream in Putaruru.

A constant flow of dying crayfish seen floating down a freshwater spring stream has caused alarm and seen officials rushing to find the cause.

Keen trout fisherman Erin Hampson-Tindale was shocked to discover what he described as 'thousands' of the freshwater crayfish (koura) of all sizes and ages floating past him during a visit to Oraka Stream in Putaruru, South Waikato, on Tuesday.

During the hour he spent there he saw a constant flow.

Oraka Stream in Putaruru where the dead freshwater crayfish were seen.

'It's shocking, there are literally thousands and thousands stumbling past,' he said.

The Oraka Stream bridge at the northern end of Putaruru.

Hampson-Tindale said it looked like a whole colony had been wiped out by something because there are even really tiny ones.

But just what the cause was remains a mystery.

Waikato Regional Council senior communications advisor Stephen Ward said council staff were immediately sent to the stream on hearing the news.

'By the time council staff arrived on the scene they could see a smaller number of koura in the water than originally reported,' he said.

Water samples have been gathered from Oraka Stream in Putaruru following the discovering of dying koura.

'They took water samples, with results expected within the next week.

'They also searched the immediate area to see if they could find any obvious sign of what might be affecting the koura but found nothing.'

Ward said the staff would be conducting a wider inspection of the area for potential sources of contamination.

The council's incident response team leader Derek Hartley said the council was determined to find the source of the issue.

'We're really keen to understand what's caused this problem for the koura,' he said.

'We haven't seen any other signs of aquatic life being affected at this stage.'

Hartley said anyone who sees more dead koura or other aquatic life in the area should contact the incident response team on 0800 800 401.

'Also, we're keen to hear from anyone who has any information about what might have caused the problems with the koura,' he said.

Hampson-Tindale said he also saw a few dead trout but there were no obvious signs of contamination in the river that he could see that might have caused the deaths.

'The water is not as clear as it can be but it could just be from the rain we had [on Monday], other than that it really looks fine,' he said.

'It's hard to say what has caused this but I know koura are sensitive when it comes to contamination.'

Hampson-Tindale said it was a depressing situation to come across.

'Not many streams would have this amount of koura. They are also the main food sources for trout and they are going to gorge on them,' he said.

'This is not something we can wake up tomorrow and forget about, it needs to be monitored.'