Cataloguing marine biodiversity will be the focus of the first-ever Antarctic census, a research project launched Tuesday involving 23 countries as part of the International Polar Year program. ((Roberto Candia/Associated Press))

New Zealand, U.S. and Italian marine scientists launched a two-month voyage to Antarctica's northern coast Tuesday as part of the first-ever census of Antarctic marine biodiversity, New Zealand Prime Minister Helen Clark said.

The census of Antarctic marine life is a multinational research project "involving 23 countries and 11 coordinated voyages to survey marine ecosystems and habitats in waters surrounding Antarctica," she said.

The 26 scientists on board the research ship will collect samples of sea life and capture images of the sea floor down to depths of 4,000 metres in previously unexplored areas, Clark said in a statement.

New assessments of ocean acidification caused by climate change and identification of new species off Antarctica's coastline are expected from the voyage, she said.

The data collected by surveys in areas not previously explored will "assist decision-making on environmental issues such as climate change and its effect on Southern Ocean ecosystems," she said.

New Zealand's Research, Science and Technology Minister Pete Hodgson said, "The oceans are truly the final frontier of exploration," and the country's research ship Tangaroa was making "a significant contribution to major international projects."

Foreign Minister Winston Peters said the voyage would provide essential information about the biodiversity and functioning of the Ross Sea ecosystem off the north Antarctic coast.

The work is part of International Polar Year, a global science program designed to advance knowledge of the land and sea environments of the Arctic and Antarctic. The first IPY was held in 1882.

The International Polar Year actually takes place over two years. Last year, scientists and governments launched a number of expeditions to study the Arctic, while this year the focus of new missions and research will be on the Antarctic.