Environment Canterbury to continue Lindavia sampling this summer

Further testing for Lindavia, the algae that causes Lake Snow, is likely to occur in Canterbury lakes in the northern part of the region this summer.

Environment Canterbury principal surface water scientist Adrian Meredith said systematic sampling for the algae was undertaken in lakes located in the southern part of the region earlier this year.

"In December 2016, we attended a workshop with researchers and Otago Regional Council on the problems they were seeing down on Wanaka and Wakatipu with Lake Snow.

"We were certainly concerned that it might be present in Canterbury lakes so during the past summer and autumn we engaged NIWA who were doing some other sampling for us [in the southern part of the region], to also sample for Lindavia algae to see if it was present in our lakes."

The results indicated the algae was present in eight lakes in addition to Lake Coleridge and Lake Opuha which were tested in 2012 and 2013.  While aesthetically unpleasant, Lake Snow - the mucus material produced by Lindavia - is not a health risk.

"The problem is the mucus material clogs filters, messes up fishing gear, filters on boats and generally it's quite unsightly," Adrian said.

Adrian said Environment Canterbury is looking to assess whether Lindavia is present in other Canterbury lakes this summer.

"This is most likely to be in association with the NIWA Lake Submerged Plant Indicator (SPI) surveys, however, it will not be until another month or two that we confirm what lakes that survey will include."

"That said, we will also be looking to 'gap fill' this issue this coming summer by some means anyway, whether by NIWA surveys, our own, or a combination of the two."

For those moving around different Canterbury lakes, the message is clear:

"Even if you can’t see the Lake Snow, it doesn’t mean Lindavia isn’t there. Be vigilant and remember to check, clean dry all equipment and boats."  

Learn how to Check, Clean and Dry

Find out how to check, clean, dry all your gear.

Frequently asked questions

What is Lake Snow?
Lake Snow is a mucus-like material that appears in lakes as a result of an algae called Lindavia.
The term Lake Snow comes from the fact that it can look like snow particles. As it ages it turns a reddish-brown colour.
Where did the Lindavia algae come from?
That's one of the big questions we're asking and some of the researchers are working on DNA analysis to find out where it might have come from.
Our best understanding so far is that it occurs in the northern hemisphere - predominantly North America at this stage, and we're trying to confirm that's the area it might have come from. But research is still ongoing at this stage.
How is it spread?
It is a lake species so needs to be transferred from lake to lake directly for it to spread into other lakes.
People boating or doing other activities on the lakes need to ensure they check, clean and dry their equipment to prevent transfer of Lindavia. They could unintentionally be transferring the algae to these other lakes where it could then start to grow and produce the lake snow effects.
Lake Snow is quite well dispersed as a small algae so it’s almost impossible to remove once it's established in a lake.
What is the issue with it?
The problem is the mucus material clogs filters, can mess up fishing gear, filters on boats and generally it's quite unsightly.
There are no health risks directly from this material. It's very much an aesthetic issue. The main people affected is fishers - filters in boats and filters taking water from lake.
What does testing involve?
Testing involves sampling for Lindavia cells which give us an indication of the potential for Lake Snow to develop. However, researchers do not yet know what triggers the excessive production of mucus by Lindavia.
What Canterbury lakes have tested positive for Lindavia?
  • Lake Heron
  • Lake Tekapo
  • Lake McGregor
  • Kellands Pond
  • Lake Alexandrina
  • Lake Ruataniwha
  • Lake Waitaki
  • Lake Benmore
  • Lake Opuha (Feb 2013)
  • Lake Coleridge (2012)
*Please note the Lake Snow produced by the Lindavia algae has only occurred at Lake Coleridge and Lake Benmore.