Blue green toxic algae, cyanobacteria.
The dry weather has meant an expansion of toxic algae growth in a number of rivers around the region.
High levels of potentially toxic algae (Cyanobacteria) has been found in the Wai-iti River at the Brightwater Bridge.
The Tasman District Council says at this site up to 70 per cent of the riverbed is covered by the algae.
The Motupiko River upstream of the Motueka – a river that is not normally monitored – currently has 40 per cent coverage.
Lower levels of potentially toxic algae have also been found on the Wai-iti River at Pigeon Valley Road and on the Waimea River at River Road, levels of the bacteria here are less than 20 per cent. The council says signs are in place, but people need to be aware of the algae’s potential presence in other parts of the Wai-iti, Waimea and other rivers, not just in the signposted areas.
River users are advised to stay out of the water and keep dogs on leashes where algae is present.
In Nelson there are currently low levels of toxic algae at the three monitoring sites in the Maitai River, but people should remain vigilant.
There is signage at points along the river providing information and photos of what it looks like (dark brown or black coloured mats).
These signs will change to a warning status when toxic algae levels are high.
– The Nelson Mail