The first successful elimination of an exotic caulerpa infestation in Aotearoa New Zealand is an example of the positive impacts of partnership between mana whenua and local government says Ngāti Manuhiri Settlement Trust Chief Executive, Nicola MacDonald.

The invasive seaweed was discovered by Te Kaunihera o Tamaki Mākaurau Auckland Council divers on 7 June in Omaha Cove, near Te Hāwere-a-Maki / Goat Island Marine Reserve.

“Time is of the essence when dealing with caulerpa” says Chief Executive of Ngāti Manuhiri Settlement Trust, Nicola MacDonald. “Our kaitiaki were in the water straight away to assess the severity of the issue and implement an immediate treatment plan in partnership with Te Kaunihera o Tamaki Mākaurau.”

“Fortunately at Leigh, there was no excess talking or twiddling our thumbs. On Monday, Ngāti Manuhiri and Auckland Council were working together to apply benthic liners with a chlorine treatment to the infested area and on Tuesday we removed the liners and confirmed that the caulerpa is dead.”

“This site is the first time we have successfully removed Caulerpa from an infested area. Although the patch was small, we have proven the importance of a fast and aggressive response to infestations to achieving what we are desperately seeking across Te Moananui-ā-Toi / the Hauraki Gulf: the complete eradication of Caulerpa.”

Caulerpa is an invasive seaweed which spreads quickly across the seabed affecting the native seaweeds our kaimoana feed on and threatening the health of our marine life. It is easily spread by small fragments caught up on boating or fishing equipment making it hard to control.

“We’ve seen what happens when it is left unchecked for too long such as the infestation at Aotea, Great Barrier Island discovered in 2021 and subsequent discoveries at Kawau Island, Waiheke Island, and Mokohinau Islands which are proving incredibly tough to eradicate.”

Ngāti Manuhiri Settlement Trust kaitiaki will continue to venture out over the upcoming weeks to monitor the area and ensure no further infestations.

© Scoop Media