Toxic algae update – a tale of contrast
08 March 2019
Toxic algae update – a tale
of contrast
Toxic algae
levels this week are on the increase across the region, but
especially in Wairarapa’s Ruamahanga catchment where some
sites are nearing, or are at, safety guideline levels.
Heavy rainfall is predicted for western parts of the region, which should help keep toxic algae in check. Greater Wellington is urging people not to swim for 48 hours following heavy rainfall, due to the risk of illness from pathogens that may washed into local rivers and streams.
Unfortunately, no heavy rain is predicted for Wairarapa so toxic algae levels are likely to remain high in some areas.
Current toxic algae
status
•
Kapiti Coast: toxic algae in the Otaki
River have increased to ~10% riverbed cover south of SH1. In
the Waikanae River toxic algal levels are ~5% riverbed cover
south of SH1. These fall within safety guidelines, but the
rain effect will make the water unsafe for swimming for 48
hours.
• Hutt Catchment: toxic algae levels remain low in the Hutt River, ~5% riverbed cover at Silverstream Bridge was the highest level observed this week. No toxic algae were observed at the Pakuratahi River at Kaitoke Regional Park. The rain effect will make the water unsafe for swimming for 48 hours.
• Ruamahanga Catchment: toxic algae levels are at ~20% riverbed cover (right on guideline levels) at both the Ruamahanga River at Double Bridges and Waingawa River at South Road monitoring sites. Care should be taken at these locations.
The Waipoua River at Colombo Road is ~5% riverbed cover.
The Ruamahanga catchment sites will be reassessed on Monday 11 March to see if stronger warnings are needed.
Be careful out there
• The best thing you
can do to keep yourself, your kids, and your pets safe is to
know what toxic algae looks like and avoid it
•
Toxic algae forms velvety or leathery looking mats on rocks
in the riverbed and are
• They are
blackish/brown to dark green in colour
• Dogs
love the musty, earthy smell of toxic algae mats and will
try to eat them if given the chance
• If
you’re not sure, it’s best to play it safe and keep your
dog on a lead.
For more information, visit: http://www.gw.govt.nz/safeswim/
Ends