Council moves to long-term management of carpet sea squirt

Media release

16 November 2022

Council moves to long-term management of carpet sea squirt

At Environment Southland’s Strategy and Policy Committee meeting this morning Council approved a move towards the long-term management of Didemnum vexillum (carpet sea squirt).

In July, an incursion of carpet sea squirt was positively identified within Rakiura/Stewart Island waters, following a report from a member of the public in May. As an exclusion pest in the Southland Regional Pest Management Plan, Council responded to this incursion with an emergency biosecurity response.

At the meeting today, staff proposed that Council reconsider the exclusion pest status of carpet sea squirt by accepting its presence in Big Glory Bay and actively preventing its spread to other marine areas, or by removing its exclusion pest status entirely from the plan and moving to a long-term management approach.

Councillors decided to accept both proposals. In the short-term Council will actively prevent carpet sea squirt’s spread from Big Glory Bay and continue monitoring. In the next few years, Council will work to remove its exclusion pest status from the plan, which will require public consultation, and move to a long-term management plan.

Environment Southland biosecurity and biodiversity operations manager Ali Meade said advice given by the technical advisory group during the response concluded that eradication of the pest was unlikely due to its spread. However, it may be possible to contain the extent of incursions and prevent further damage to pristine marine environments.

Mrs Meade said removing carpet sea squirt from the plan did not mean it would be left to spread throughout the region.

“While we are accepting the presence of this pest in Big Glory Bay, we will continue to monitor it, educate the public and business, and attempt to contain it.

“This approach could result in improved biosecurity management for a range of other species as we spread awareness about the risks associated with vessels moving to and from different waters,” Mrs Meade said.

A formal review of the Southland Regional Pest Management Plan will be required to change carpet sea squirt from an exclusion to a progressive containment pest.

Committee chair Lyndal Ludlow said its vital that we limit the spread of carpet sea squirt to protect other pristine environments.

“While the Council is going to be actively monitoring and working to prevent the further spread of carpet sea squirt we are also calling on the public to be vigilant. Report suspected marine pests to us and ensure your vessel and gear are clean.”