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
Motu-kauati-iti | Corsair Bay
Incident date: Saturday 10 January 2026
Last updated: 8.40pm, Saturday 10 January 2026
Health New Zealand | Te Whatu Ora has issued a health warning after being advised by authorities that there has been a discharge of untreated sewage into Motu-kauati-iti | Corsair Bay. This health warning includes Corsair Bay | Motu-kauati-iti, Cass Bay | Motu-kauati-rahi at jetty, Cass Bay | Motu-kauati-rahi at beach, and Rāpaki Bay at beach.
Water quality at the affected site is not considered suitable for recreational uses including swimming because of the risk to health from the bacteria and other pathogens.
Eating fish or shellfish from these sites should be avoided. If fish are eaten, remove the gut and liver and wash in clean water before cooking.
Find out more: Health warning - Unsafe water quality.