An investigation will be made into the risk of pests and pollutants ending up in the water at a boat cleaning facility in Bluff.

It follows a letter addressed to Environment Southland by Fiordland Marine Guardians which raised concerns about a synchro lift operated by South Port in the far south.

The machine is used to lift vessels out of the water for cleaning and maintenance purposes at the country’s southernmost commercial deepwater port.

But the guardians said they had long been concerned about inadequacies at the facility because of the potential for marine pests to be released into the environment while using the lift.

“This has been happening since it was put in place due to a lack of bunding [retaining wall] or other suitable containment structures," the letter read.

“The cleaning of boats on site could also potentially result in paint and oil polluting the Bluff Harbour area.”

The group highlighted Undaria — an invasive seaweed — as a pest organism that would breach the rules if washed back into the marine area.

It said the port had long been recognised as a site where Undaria could be transferred, and requested the council investigate “pollution events” from the use of the lift.

Speaking at Tuesday’s meeting, Fiordland marine guardian Ali Ballantine said places such as Bluff and Rakiura were key sites where marine pests could be transferred to Fiordland, hence their concern.

Environment Southland biosecurity and biodiversity operations manager Ali Meade said the council would do a full investigation on the synchro lift and whether it was compliant.

Council and South Port set to team up

In a twist, the council could soon be working closely with South Port to address the shortage of hull cleaning facilities on Southland’s coast.

A subsequent council report titled Bluff Haul Out explained a renewed collaboration was underway between the two groups.

Environment Southland, a 66 percent majority shareholder of South Port, hoped to utilise the port's synchro lift at a facility that would be built next to the technology.

An internal working group had been backed by a $80,000 budget and would develop a business case by mid-2025.

Efforts so far to improve the lack of hull cleaning in the southern region had been fraught.

A 2019 agreement with Invercargill City Council (ICC) saw the regional council invest $400,000 in a Bluff boat ramp project, but a designated haul out area never eventuated, with ICC syphoning that money into ramp upgrades.

Environment Southland partnerships manager Nick Perham said his organisation had been unsuccessful in trying to get details of the spend from ICC.

“I take it we’re asking some pretty serious questions about that,” councillor Jeremy McPhail said.

In response to questions from Local Democracy Reporting, South Port environmental and infrastructure manager Frank O'Boyle said the organisation understood concerns about potential discharge of pest organisms into the coastal marine area.

South Port was fully supportive of a hull cleaning facility at Bluff, and several options were being considered, O'Boyle said.

LDR is local body journalism co-funded by RNZ and NZ On Air