Status: superior
The water quality of the marine reserve is rated 'good to excellent' by Auckland Council. Because of consistently high quality results, the marine reserve is designated a low-risk location for swimming.
Trend: stable
No consistent change in water quality has been recorded in the last 20 years. No change is expected in the near future.
Monitoring
Auckland Council has been monitoring the water at two sites within 10 km of Tāwharanui (Goat Island and Ti Point) monthly since 1993 for a standard range of parameters including salinity, pH, turbidity, suspended sediment, nitrate and enterococci bacteria.
Tāwharanui and Anchor Bay have a history of excellent water quality, so they are no longer included in the council’s summer Safeswim monitoring programme.
Auckland Council also monitors the Tāwharanui stream – see surrounding land.
Reports
Auckland Council publishes the Marine Water Quality Annual Report each year.