Ninety percent of New Zealand's native sea and shorebirds and more than a quarter of marine mammal species are at
risk of extinction, according to an official report released today.

Twelve sea and shorebird species, including albatrosses, shags, petrels and penguins, were facing an extremely high risk of extinction, according to the report produced by the Ministry for the Environment and Statistics New Zealand.

Five marine mammal species were also reported as nationally critical, including orca, sea lions, the southern elephant seal, and the Maui dolphin, the world's smallest and rarest dolphin, of which only 63 remain.

New Zealand's Secretary for the Environment Vicky Robertson said that marine areas around New Zealand were facing multiple and cumulative pressures that had been building over generations.

"Fishing bycatch, introduced predators, and habitat change are among a raft of reasons for the poor state of much marine wildlife," she said.

The report said global greenhouse gas emissions posed one of the greatest challenges for the marine environment, causing the oceans to become more acidic and making it difficult for shellfish, including plankton, to build their shells.

"Plankton form the base of the food chain and are a direct or indirect source of food for almost all marine animals," Robertson said.

The report said the country's marine fauna was of international importance, with nearly half the world's whale, dolphin and porpoise species found in its waters and almost a quarter of the world's sea bird species breeding in New Zealand.

- dpa