Marine health warnings
We monitor marine sites regularly over the summer to check for faecal indicator bacteria.
Sites that we monitor are given a long-term grade prior to each summer season for suitability for swimming . The grade is based on the last five years of sampling.
Sites that are not recommended for swimming, or any water-based recreation, because of their long-term grade are shown as red on the Land Air Water Aotearoa (LAWA) website and signage should be in place at the site.
This summer, the long-term grades at 13 bays in Whakaraupō Lyttelton Harbour and Akaroa Harbour are replaced with a new predictive water quality tool. This tool provides real-time information about the conditions. Learn more about the predictive water quality tool.
Temporary health warnings are issued when a site was graded as good to swim but there is now an increased risk of faecal contamination.
Faecal contamination poses a risk to health, it can cause gastrointestinal illnesses, respiratory diseases, and eye, ear, nose, throat and skin infections.
You can also help stop the spread of marine pests that pose a major threat to our region's beautiful coastal waters.
Temporary health warnings
Health Warning lifted for Algal Bloom at Koukourarata Port Levy
Incident date: Friday 13 March 2026
Last updated: 1 pm, Thursday 23 April 2026
Health New Zealand – Te Whatu Ora has lifted its health warning for swimming and other water-based recreational activities at Koukourarata Port Levy.
Latest water testing results show that the number of toxic harmful algae cells is now below guideline values for recreational use (e.g. swimming and other water-based activities)
The warning issued by New Zealand Food Safety (NZFS) remains in place advising the public not to collect or consume shellfish gathered from the northern side of Banks Peninsula, due to the risk of paralytic shellfish toxins causing illness. The warning extends from New Brighton to the northern side of Hickory Bay and includes Whakaraupō Lyttelton Harbour.
Anyone who becomes ill after eating shellfish from an area where a public health warning has been issued should phone Healthline for advice on 0800 611 116, or seek medical attention immediately. Please also contact your nearest public health service and keep any leftover shellfish in case it can be tested.
For further details visit: Shellfish biotoxin alerts | NZ Government
Rāhui issued for Koukourarata and Whakaraupō
Te Rūnaka o Koukourarata advises that, due to the presence of a toxin producing algal bloom currently affecting the Koukourarata / Port Levy Harbour, and the associated risk to public health, a rāhui has been placed on the taking of shellfish from the harbour.
A review of this rāhui will be undertaken once further water quality and toxin test results have been received.
Ngāti Wheke have also issued a rāhui on taking shellfish from Sumner beach, Scarborough, Taylors Mistake and all sites in Whakaraupō.
Find out more: Land, Air, Water Aotearoa (LAWA) - Can I Swim Here?