Kāpiti Coast District Council is advising dog-owners to keep an eye out for toxic algae in the district’s waterways as
the temperature rises. That includes lagoons in parks and reserves as well as rivers and streams.
Greater Wellington Regional Council are advising there are now dangerous levels in Waipoua River in the Wairarapa and
elevated levels in Te Awa Kairangi (Hutt River).
Environmental Standards Manager Jacquie Muir, says seasonal changes that occur around this time of year impact on algae
levels and it’s likely that we’ll soon see toxic algae in some parts of Kāpiti.
“We’re noticing the water levels slowly dropping and temperatures rising so it is possible cyanobacteria, an algae which
is toxic to humans and deadly for dogs, will appear. We’re increasing signage at recreational swimming sites and taking
this opportunity to remind people to be aware of the risks,” says Ms Muir.
The Council will maintain its seasonal monitoring program of recreational swimming sites, in partnership with Greater
Wellington Regional Council. This happens weekly during the summer months.
Test results from popular river, lagoon and beach locations are available on the Council’s website.Check for toxic algae
Signage at popular swimming sites is increasing to remind people to check for signs of toxic algae.
Toxic algae (cyanobacteria) generally form brown or black mats that grow on rocks in the river bed. Mats that come loose
from the river bed can wash up on the river bank or form floating ‘rafts’ in shallow areas. When exposed, the mats may
dry out and turn a light brown or white colour and may also produce a strong musty odour. Cyanobacteria differ from
harmless bright green algae, which often form long filaments.
It is important to keep an eye on babies and toddlers who may put objects in their mouths. Seek emergency medical
attention immediately if anyone in your group swallows toxic algae.
Caution should also be taken when exercising dogs by rivers as they are strongly attracted to the musty smell of drying
mats and will eat them where they can, which could be fatal. The algae is quickly dispersed and deactivated by salt
water, so it’s safer to walk your dog at the beach instead of at rivers during the summer.
Given the rapid growth of toxic algae and its potential change in coverage between weekly monitoring points people are
also urged to know what it looks like.
“If you suspect toxic algae might be present then keep your dogs out of the water and let us know,” says Ms Muir.
Greater Wellington Regional Council has more information about toxic algae at www.gw.govt.nz/toxic-algae