Ravenous giant snails uncovered during search of container vessel

By AINSLEY THOMSON

Stevedores inspecting a ship in Auckland found giant African snails that can grow to the size of big rats trying to slither their way into New Zealand.

The Ministry of Agriculture and Forestry said that if the snails - which eat more than 500 species of plant and are one of the most invasive snail species in the world - became established, they would devastate New Zealand's vegetation.

The 21 snails, which carry a form of meningitis that can be passed to humans, were found on Sunday night on the container ship Sofrana Bligh and are believed to have hitched a ride from the tiny French Pacific islands of Wallis and Futuna.

MAF programme manager Mike Fenton said the stevedores alerted quarantine officers who inspected the containers yesterday, finding the remaining snails and their eggs.

The snails on the ship ranged from 2cm to 6cm, but can grow up to 20cm and can weigh around 1kg.

The stevedores were accredited under MAF's new programme to check 100 per cent of imported sea containers.

Mr Fenton said the discovery was evidence the system was working.

However, Forest and Bird biosecurity awareness officer Geoff Keey said the holes in MAF's accreditation system meant it was simply the luck of the draw whether major pests like the snails were spotted by competent stevedores or got ignored by unscrupulous or incompetent people, who faced no barriers to accreditation under MAF's system.

"We can thank the sharp eyes of the stevedores for averting a potential catastrophe.

"MAF can't claim much credit, given Forest and Bird accredited a cat under MAF's system in just eight minutes on the internet."

Auckland Museum curator of entomology John Early said giant African snails were spectacular to look at because of their size and would eat just about anything, including New Zealand native plants.

They are prolific breeders. Each contains female and male reproductive organs and in a typical year an adult will lay about 1200 eggs.

Mr Early said that because of their dramatic size and capacity to eat anything they had been popular as pets.

The US Department of Agriculture has reported an incident where a young Florida boy smuggled three from Hawaii to keep as pets. His grandmother released them into the garden. Seven years later there were more than 18,000 snails and it took the State of Florida almost 10 years and $1 million to get rid of them.

The snails can live as long as nine years and cold weather is no problem - they go into a state of hibernation and can survive in even snowy climates.

The snails are originally from an area south of the Sahara in East Africa, but are now found in parts of the Pacific, where they were taken as a source of food, and in Asia.