Action urged over ships' dye discharge

The Russell Open Aquarium Group says this image shows a Talley's-owned fishing vessel, the super seiner Capt MJ de Souza, using fluorescein dye to catch skipjack tuna off Doubtless Bay.

A Bay of Islands environmental group believes a fishing company's use of dye to catch skipjack tuna off the Northland coast is illegal and is urging authorities to take action.

The Russell Open Aquarium Group has been collecting evidence of Talley's fishing boats using a green dye called fluorescein.

Group member Gary Morris said crews threw the dye into the water as they were hauling in their nets. The dye formed a "green curtain" the fish would not swim through as the net was closed, ensuring they did not escape.

Mr Morris said the group believed use of the dye amounted to discharging a contaminant, which required a consent under the Northland Regional Council's Coastal Plan.

With three Talley's-owned purse seine fishing boats active off the Northland coast last summer, he believed thousands of pottles of the dye had been thrown into the sea without consent.

However, Talley's operations manager Andy Smith, of Nelson, said the dye was legal and non-toxic. The company had been using it since 2002 but it had been used in the US much longer.

It was also used by liferafts to increase visibility to searching aircraft and to colour American harbours green on St Patricks's Day. It dissipated within an hour.

"I'm pretty comfortable with it. We don't often fish inside the 12-mile limit anyway, and anything outside that has nothing to do with the Northland Regional Council."

The company had provided "plenty of information" to the council about its use of fluorescein, Mr Smith said.

The Northland Regional Council confirmed it had received a complaint about use of the dye.

Spokesman Murray Soljak said the council had written to the fishing company concerned asking it to demonstrate that the practice was legal. The council had also requested data on the substance being used.

Mr Morris said skipjack tuna were an important part of the food chain for dolphins, sharks and marlin. Any curbs on the use of fluorescein would help those species as well as preventing contamination of Northland waters.

Fishing companies used to use tuna bombs for the same purpose but found the dye was more effective, he added.

Fluorescein was first used to dye the Chicago River green on St Patrick's Day in 1962. However, it was replaced with a vegetable-based dye in 1966 at the urging of environmental groups.