Whangamata harbour in the Coromandel should be quarantined until the mysterious sponge-like growth destroying shellfish in the waters is controlled, Green Party Biosecurity spokesperson Ian Ewen-Street said today.

The Whangamata Harbour Master has reported that since Christmas the sponge has spread across more than half the harbour, destroying hosts such as mussels, oysters and barnacles.

Mr Ewen-Street said efforts of the Ministry of Fisheries, NIWA and the Waikato Regional Council in seeking to identify the growth (tentatively thought to be Didamnid ascidian) and simply hope that it would decrease over the winter were just not enough.

"It may be that the sponge is essentially harmless and experiencing a 'bloom' event, but the risk that it is something more serious is one we should not take.

"Auckland's Painted Apple Moth problem also started from small beginnings," Mr Ewen-Street said. "If MAF had acted more effectively to eradicate the moth when it was first discovered, then the current furore over spraying wide areas of residential housing wouldn't be an issue."

"While we don't know exactly what is, the sponge has already proven it kills mussels, oysters and other shellfish, and so has the potential to destroy our marine farming industry, which is worth more than our wine industry.

"We cannot risk having it transported on the hull of a boat to places such as the Marlborough Sounds.

"The Minister of Biosecurity should immediately ensure that both MAF and the Ministry of Fisheries take appropriate action for the positive control and possible eradication of the sponge."

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