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Danish scientists have given New Zealand a tentative "thumbs up" for having negligible amounts of ocean pollution in fish samples collected off Banks Peninsula.
Scientists aboard a Danish frigate that berthed at the Port of Lyttelton this morning said a sample of bile taken from a trigger fish caught just outside Lyttelton harbour yesterday showed pollution levels only slightly above those taken in pristine Arctic waters.
The 49 scientists aboard the Danish Thesis Class frigate HDMS Vaedderen are taking part in a global expedition, Galathea 3, which covers a range of projects including producing a global pollution map and calculating how much carbon dioxide is absorbed by the world's oceans and its likely effect on climate change.
Fish, mussels, snails and crustaceans are collected during the voyage, which began in Copenhagen four months ago and has so far taken the scientists to Greenland, the west coast of Africa, Australia and the Solomon Islands.
From Lyttelton, the expedition will head for the Antarctic Peninsula, Vaplaraiso and Antofagasta on the west coast of South America, the Galapagos Islands, the United States Vigins Islands, the Azores and back to Copenhagen.
During the 8-1/2 month voyage, the frigate lent to the expedition by the Royal Danish Navy will cover about 39,000 nautical miles, calling at 16 ports along the way.
At a news conference aboard the ship this morning Danish scientist Jan Christensen said the most unpolluted site found so far was in the Arctic Ocean off Greenland, where there were "no humans for thousands of kilometres".
By comparison, he said, fish sampled from Copenhagen Harbour -- "our own home garden" -- showed the highest levels of pollution.
"That's bad," Associate Professor Christensen said.
The trigger fish caught outside Lyttelton yesterday and analysed this morning in six containerised laboratories specially fitted aboard the frigate, dubbed "research city," indicated low levels of ocean pollution here.
"It's not as low as Greenland, but it's very close," Assoc Prof Christensen said.
"We cannot say New Zealand is unpolluted, but we can say the fish we (caught) from just outside the harbour gave no indication that it's as polluted in other harbours where we have been.
"So you've done a good job in New Zealand."
Assoc Prof Christensen, a chemistry specialist, said the global pollution map he hoped to produce at the completion of the latest expedition would be a world first.
A detailed "fingerprint" of the world's ocean pollution would emerge after detailed analysis back home in Denmark, but he told NZPA the tests on bile extracted from fish taking just "half an hour" in the on-board labs gave a "fair indication" of local pollution levels.
Samples collected during the expedition would keep Danish scientists busy for "perhaps the next 20 or 30 years," he said.
The Galathea 3 expedition continues a long tradition of Danish maritime expeditions aiming to conduct research and take modern science out of the laboratory.
The name Galathea derives from one of the 50 daughters of the Greek sea god Nereus.
Assoc Prof Christensen said the first Galathea expedition took place about 150 years ago and the second was in 1957. Tonnes of samples had been collected during both expeditions and many were still being analysed in Danish universities and research centres.
Expedition scientific leader Professor Katherine Richardson's project is to find out how much atmospheric carbon dioxide the ocean absorbs in order to discern the role of the seas in mediating climate change.
Prof Richardson said computer analysis showed that the world's oceans had taken up about half the extra carbon dioxide (CO2) that humans had generated.
"The oceans have really done us a great service," she said. "Most people believe we only get fish out of the ocean, but it's actually buffered us against climate change.
"The problem is, it's not going to continue to do that."
Prof Richardson explained that CO2 broke down calcium carbonate and when it was absorbed into the ocean and became acidic it affected the myriad of marine organisms that made calcium carbonate, such as lobsters, crabs, fish, corals and some seaweed.
She said most people would think of the corals and other minute organisms that "ultimately fall to the bottom and make chalk cliffs, like the white cliffs of Dover".
The world's corals thrived in the 1880s when the level of CO2 in the oceans was optimal.
Assuming CO2 emissions continued at current levels, computer projections showed that as early as 2065 there would be no regions in the oceans where conditions would be right for the production of calcium carbonate.
Prof Richardson said scientific opinion on climate change varied greatly and many disagreed about the conditions that caused it, making it difficult to "get the climate change message across".
"But there is nothing you can blame for this ocean acidity except the CO2 in the atmosphere."
- NZPA
