A wildlife team has been sent  to an offshore conservation haven feared to be in the path of the Rena's latest oil spill. Up to 10 tonnes of oil leaked from the ship overnight on Saturday and the likely path of that oil is Tuhua Mayor Island. The island is 36 kilometres away and the oil may reach there by Wednesday this week.

The island is protected and right now is when many marine bird species on the protected island are nesting or feeding chicks.

Aerial observation flights would today monitor the fresh spill and track its trajectory.

A Maritime New Zealand spokeswoman said a wildlife team had been sent to Mayor Island today to assess what needed to be done.

"We've got a little bit of time to organise and that's why the wildlife teams have gone out today.''

The 1277ha volcanic island is owned by Te Whanau-a-Tauwhao, a sub-tribe of local iwi Ngai Te Rangi. Most of its land is under a conservation covenant, with about 2 per cent set aside for accommodation and a planned marae.

 A roughly 5km-long marine reserve on the northern end of the island helps to replenish fish stocks in a restricted fishing area around the rest of the island, including the southern end that faces the Rena.

John Heaphy, who works with the local Department of Conservation office, said an the main focus was on marine species.

Among the species that call the island home are a variety of different petrels, little blue penguins, white-fronted terns, red-billed gulls and a small but increasing fur seal population.

Inshore species include pateke, or brown teal, orange-fronted parakeets, North Island kaka and brown kiwi, tuatara, and a range of more common species.

Mr Heaphy said the concern at the moment was for the marine species.

"We're not sure yet what the impact is for the likes of some of the nesting petrel species at the moment that feed out at sea.''

Birds could be getting lightly oiled while they were out feeding before coming back ashore to either incubate eggs or feed chicks.

"We don't have any information yet on that sort of impact for birds that are actually flying direct from the sea onto the land,'' Mr Heaphy said.

"Unfortunately it also coincides, the spill, with the start of the main nesting time for a whole lot of species. Bad timing all round for everything really.''

Teams had been out over the last few weeks picking up oiled wildlife during the day, and looking for penguins coming ashore at night.