KEY POINTS:
The big research voyage just completed by scientists in New Zealand's Ross Sea may give the Government the final ammunition it requires to seek special United Nations protection for the icy Balleny Islands.
New Zealand is building a scientific case for a marine protected area in international waters
around the archipelago - described as a marine "oasis" on the edge of the Ross Sea.
Earlier voyages in 2001 and 2004 collected data to show that ecological processes around the islands - a 195km-long chain 250km off the Antarctic coast - were critical to the healthy functioning of the larger Ross Sea ecosystem.
But the scientists who returned to New Zealand this month on the research vessel Tangaroa may help gain the high seas marine protected area sought around the islands by showing comparable data for seamounts further north, which have relatively low levels of biological diversity.
The areas they surveyed included the Admiralty seamount and Scott Island, to the east of the Balleny Islands and almost directly north of Scott Base.
"We were looking at how important are the Ballenys in comparison to other areas in the Ross Sea," seamounts expert Dr Malcom Clark said.
Some scientists have speculated the icy Balleny Islands may eventually provide a foothold for wildlife dispersed by the effects of global warming.
They were already the only place chinstrap penguins were known to breed in the Pacific sector of Antarctica.
The Ballenys rise from a seafloor depth of nearly 2000 metres, directly in the path of circumpolar ocean currents, forcing an upwelling of nutrient-rich waters where the Ross Sea meets the Southern Ocean.
Because they are the only islands at this latitude for thousands of kilometres in both directions they also provide essential breeding and nesting habitat for land-dependent Antarctic seal and seabird populations.
Several whale species are known to feed in the area, some of them migrating long distances to get there, and the area is viewed as a hotspot of Antarctic marine life, with a greater diversity of algae species than in the rest of the Ross Sea.
"One of the interesting things we will get from this dataset is better understanding of whether the fauna around the Ballenys is really special - as we think it might be," said fisheries scientist Stu Hanchet.
"Are the Ballenys really special ... we have to have valid reasons for protecting them, and we're giving a regional context to the work done around the Ballenys," said Dr Hanchet, the project leader on the latest voyage.
"Without that regional context it's very hard to answer questions such as 'why do we have to protect this?', 'is it special?' 'is it really representative'," he said.
- NZPA