Elevated levels of potentially toxic algae in the Waihopai River at Kennington and Waiau River near the Excelsior Creek inflow.
The Ata Whenua Fiordland Undaria Control Programme aims to contain Undaria pinnatifida (Undaria) within the Te Puaitaha / Breaksea Sound - Tamatea/Dusky Sound complex and eliminate it from Taiari / Chalky Inlet. Environment Southland oversees the programme, which received two years of funding through Jobs for Nature – Mahi mō te Taiao in 2021.
Environment Southland, the Department of Conservation and Biosecurity New Zealand, with support from the Fiordland Marine Guardians, have been working together on an intensive control programme for Undaria in Te Puaitaha / Breaksea Sound since 2010. In 2021, Jobs for Nature funding provided an opportunity for a refreshed approach with the large-scale removal of Undaria from within the fiord.
A regional scientific dive team was trained to tackle the challenging work in the Te Moana o Atawhenua / Fiordland Marine Area. This meant the programme no longer relied on recruiting diving expertise nationwide.
In November 2022, mature Undaria plants were discovered on the south side of Tau Moana / Resolution Island in Tamatea / Dusky Sound. The dive team was rapidly redeployed to survey areas around the new infestation to determine its spread.
The main incursion in Duck Cove on the south coast of Resolution Island was found to span over two kilometres. Divers also observed small numbers of mature plants at multiple locations within the fiord. Biomass removal continued across all ‘new’ infestation sites, and the team surveyed high-risk areas from Rakituma / Preservation Inlet north to Taitetimu / Caswell Sound, with no additional new finds of Undaria or other marine pests.
The team are undertaking monthly containment and surveillance trips through winter 2023. Significant follow-up efforts will be required in the main infestation areas in the FMA to slow its spread.
Photo credit: Kath Blackmore DOC
The most significant risk of Undaria getting to a new area in Fiordland is being spread accidentally by people via boats, marine gear (ropes, chains, anchors, pots etc.) and onboard seawater. This risk applies to all marine pests.