Rock of salvation

2010 is the International Year of Biodiversity. Andrea Crawford, of the Department of Conservation, finds a small island just off the coast from Dunedin is providing just the sort of habitat the year is designed to promote.

There's a yellow-eyed penguin patiently sitting on its nest under a tree on Green Island, just off the Brighton coast near Dunedin.

A sleek fur seal blunders through the spiky, low-growing taupata, shoves his whiskered head into the penguin's personal space, gives a loud bellow and forces the penguin to evacuate its sheltered haven.

The penguin - hoiho in Maori - is not about to argue with a creature 20 times its size, so it waddles away in search of a safer home.

Blinking its distinctive eyes, it shakes its yellow headband, as if it can't believe the cheek of its fellow islander considering the work it's put into making a nest.

The nest, it should be said, is so unstructured it is just called a bowl - a smooth dent in the dirt below vegetation.

Egg-sitting duties are shared by both parents, who defend their patch with squeals and squawks, though many nests are nearby.

The seal appears smugly content with its new/used abode, which offers sea views and shelter from the howling southerlies that frequently hit the island.

But today there's only a slight breeze, the sun is out and it's perfect nesting and loafing weather for penguins and ideal conditions for Department of Conservation (Doc) staff to do their annual hoiho nest and chick count.

I'm on the island with Doc rangers Jim Fyfe and Graeme Loh - Mr Fyfe is checking on the penguins while Mr Loh's task is to nurture the Cook's scurvy grass (Lepidium oleraceum) plants on the island.

The plant belongs to the cabbage family and was discovered by Captain James Cook's botanists in 1769.

Captain Cook fed it to his crew to protect them from scurvy.

It has now almost entirely disappeared from New Zealand and teeters on the brink of extinction.

Mr Loh places protective battens around the precious plants to protect them from seals and cuts back weeds around the plants.

Taupata grows like a weed on the island and he is anxious that it doesn't smother the valuable Lepidium specimens.

Green Island is off-limits to visitors.

It's a nature reserve and no-one is allowed to land there without a permit.

Permits are issued for essential conservation management, usually for the purposes of scientific investigation.

We hire a ride to the island on a Brighton Surf Life Saving Club rubber dinghy, although I don't feel so lucky during the ride as we get soaked through by high waves.

We soon warm up after changing into dry clothes and scrambling up the island's rocks and cliffs to the start of our penguin hunt.