Biosecurity in the Hauraki Gulf

Man’s best friend has the nose for finding stowaways.

Environmental News Issue 28 Winter 2011

Every month as a freight barge heads out of Half Moon Bay on its way to Rakino Island in the Hauraki Gulf with household goods, cars, building materials and other items from the mainland, Brian Shields and his dog Tui are onboard checking for unwanted stowaways.

Brian is a biosecurity specialist at the Auckland Council working in the Hauraki Gulf. He travels with the barge on its monthly run to Rakino, doing an inspection of the barge and the goods on board with Tui, who is trained to detect rodents by scent making sure none reach the pest-free island.

“I have checked the barge every month for a year now and we’ve haven’t found anything yet. However, when you have a large amount of freight and items like building materials, there is always the risk that a rat or mouse or even a possum is hiding amongst it,” says Brian. “As well as Tui being there specifically for rodents, I’m there for a visual check for other pests like possums, Argentine ants and rainbow skinks. Together we cover a lot of bases.”

Brian recently inspected a house which was heading over to Rakino. He and Tui went through a scent and visual check of the entire building, including the roof cavity. Bait stations were also put into the house for the journey and eventual site placement. Brian also uses the trip to check the bait stations on board the barge and the array of bait stations that are on the island foreshore. Together with 17 DOC200 traps, this creates a formidable line of defence for Rakino, which has been free of animal pests since the last Norway rat was eradicated in 2002. The DOC200 traps act as both a trap and a surveillance tool and are set for rodents and mustelids (weasels and ferrets), with baits used that will attract these species. These traps are maintained on separate visits to the island by Brian with the help of island residents.

“The locals are on board with what we’re doing – they value having the island pest-free and work well with us,” says Brian. The freight barge is operated by SeaLink, which is currently undergoing the certification process to gain a Pest-Free Warrant. This is a joint Auckland Council – Department of Conservation biosecurity accreditation for their vessels and premises. “It’s about SeaLink reaching and maintaining a level of standards, and having standard operating procedures in place for things like pest control and monitoring,” says Brian. “They will also have biosecurity messaging as part of their core business to get the warrant.”

SeaLink has been very supportive of council initiatives and programmes. Undergoing the Pest-Free Warrant is very valuable as it gives SeaLink the official seal of approval for the good work that is already going on. All vessels should have pest control such as bait stations or traps on board and around where they’re moored. Pest sightings should also be reported immediately. If a pest like a rat or a possum is spotted on board or around the marina and that boat is about to head out to the Hauraki Gulf, it’s essential that the sighting be reported to the Auckland Council or DoC so it can be dealt with by experts.