Student receives grant to study toxic algae growth

18:08, Mar 04 2014

A Canterbury University student hopes to eventually provide councils with tools to predict the growth of toxic algal blooms in the region's rivers.

Tara McAllister, 21, has received a $25,000 grant from Environment Canterbury to develop her initial research into the causes of toxic algal blooms.

The money will go towards procuring equipment, data modelling and travel costs.

She spoke at yesterday's Orari-Opihi-Pareora zone committee meeting in Timaru.

"It's really exciting, but it's a massive project. We've barely scratched the surface of it," she said.

Over the summer she analysed the data from 10 sites across the region, including the Opihi, Pareora and Waihao rivers.


"What was interesting was the fact we found phormidium everywhere, even in catchments where it was supposedly at low levels," Ms McAllister said.

Her initial research would form the basis for her Masters of Science project over the next two years.

Phormidium appears as dark brown-black mats that become attached to rocks along riverbeds. Contact by skin or swallowing can cause rashes, skin and eye irritation, allergic reactions and gastrointestinal upset. It can be fatal to dogs.

Although her early research has been "broad", Ms McAllister said she had found some interesting patterns.

"Phormidium growth did not appear to be correlated to higher temperatures, at least in Canterbury," she said.

"There have been days where the Temuka River was as cold as eight degrees, and yet still there were significant blooms."

However, her early research did seem to confirm that higher river flows would reduce phormidium cover.

"Some councils say it needs to be ‘three times the rate of a normal fresh' [to clear out phormidium], but it really seems to depend on the character of the actual river," Ms McAllister said.

"In the Pareora, it's quite embedded and takes quite a lot to roll the rocks over."

Her research during the summer involved a lot of ‘hands-on' water sampling.

"I really enjoyed wading into the Ashley River, even if the mosquitoes took a big bite out of me," she said.

She hoped, by the end of her research, she would be able to provide some form of computer program to predict in advance the likelihood of an algal bloom.

"This could even include analysing through unmanned aerial vehicles. That's my ultimate goal. Phormidium is a huge issue, and we need to get on top of it."

The Timaru Herald