Canterbury coast a bottle dump for southern ocean?

Press, 29 January 1982, Page 13

Canterbury coast a bottle dump for southern ocean?

Leave no bottle unturned on the beach this summer. It may contain a message for you from the seas around Antarctica. Some remarkable bottle finds have been made on the Canterbury coast over the last few years, and the scene is being set for more in future.

Indeed, it may well be that this coast is a natural bottle dump for drift bottles in the wide and stormy reaches of the Southern Ocean.

Tourists continue to go to the Antarctic by sea every summer. These cruises to the Antarctic have been taking place every summer from the 19605.

The cruises mostly go from southern South America to the spectacular coasts of the Antarctic Peninsula and its nearby islands. Foremost in this development of packaged tours to the Antarctic has been Lindblad Travel, of New York, whose plush, ice-strength-ened vessel Lindblad Explorer, of a mere 2300 tons, has carried nearly 100 inquisitive and wealthy passengers each voyage to the Antarctic every year since she was built in 1969. Like the other vessels carrying tourists to the continent, she visits only the Peninsula or the Ross Sea region. This year she leaves for the first of two short cruises from Bluff to the Ross Sea on December 14. Tourists like wine. The Lindblad Explorer has an unusual cellar of wines picked up from all over the world. When full of tourists, she generates a considerable number of empty wine bottles each day in the din-ing-room and the bar. These empty bottles are usually

jettisoned at sea together with other refuse. Uncorked and uncared for, they all sink to the bottom of the oceans, and are there incorporated into the sediments of the deep oceans — the ultimate rubbish dump on our planet. In the summer of 1979-80, on a trip in the Lindblad Explorer, I was struck by the remarkable labels that many of these wine bottles carried,

By NIGEL WACE, head of the biogeography and geomorphology department at the Australian National University, Canberra. He will join the Canterbury bottle finders when the Lindblad Explorer returns to Lyttelton today.

and started collecting bottles from the dining saloon after dinner-so that I could soak the labels off in my cabin overnight. By mid January I had accumulated 80 bottles (to the dismay of the poor cabin steward). At the "asado” (barbecue) on a shingle beach by the Argentine base on Lauri Island in the South Orkney Group, we had a cork-hunt, and found enough good corks to fit them all. These corked bottles, all with written mes-

sages inside were later hurled into the turbulent sea at a bottle-throwing party held on the ship’s poop in Drake Passage, just south of Cape Horn, on January 16, 1977. For nearly three years, back at home in Australia, I thought little more of the event; I did not really expect that any of the bottles with their second-hand corks could survive the rigours of some of the stormiest seas in the world, where the great churning gyration of ice from the Weddell Sea sweeps north into the Atlantic, and across the wide reaches of the “furious fifties” and the “roaring forties" in the south Indian Ocean. Even if a bottle was to avoid the icebergs and survive the storms, it might well be samshed on the rocky coasts of South Georgia, Kerguelen or Macquarie, or one of the other remote islands that lie downwind in the westerlies which drive the surface ocean currents clockwise around the Antarctic in the West Wind Drift. The experiment of hurling all the bottles into the ocean, just where the West Wind Drift flows fastest, as its waters squeeze between the tail of South America and the Antarctic Peninsula, was worth trying, if only to entertain the tourists or to serve as a practical exercise after a talk on plant and animal dispersals between the islands and continents of the south. But I had no high hopes that any messages would find their way back to me.

I was wrong. In September, 1979,1 had a letter from Mrs Judith Bain of Christchurch, enclosing one of my hand-written mes-

sages. Her mother-in-law had seen the bottle bobbing about in heavy surf just off the shingle beach at the outfall of the Rakaia River, and had grabbed it as soon as it was cast ashore. Inside was a soggy bit of paper, sharing the bottle with a centimetre of seawater which had leaked in through the disintegrating cork. The Rakaia shingle spit is a steep, high-energy beach. A bottle would soon be smashed against the stones in the surf, so it is likely that my bottle had only just arrived there when the observant Mrs Colin Bain saw and seized it. If it had, indeed, only just arrived, it had made the journey of at least 11,000 miles in 976 days — an average rate of travel, of about 11.27 statute miles per day (or 21cm per second) for 32 months. Is this a world record for fast long-distance bottle transport? There are plenty of accounts in the scientific literature of faster drift rates of bottles and drift cards over shorter distances than this, but possibly none that have average speed like that of the Rakaia bottle over such a long distance. Long-dis-tance drift bottles have been picked up on other New Zealand coasts — especially on the west coast of the North Island.

One good contender for the record stakes, both on grounds of time and distance travelled is the bottle found on September 7, 1952 among sand dunes in Wanganui Bay. This bottle had been jetti-

soned south of the Falkland Islands in 1904. It had probably made a journey rather similar to the Rakaia bottle, but had evidently lain undetected in the dunes for nearly 50 years!

The Rakaia bottle is not the end of these recent Canterbury Bottle Tales. On November -3, 1980, Mr John Grindrod, a research student at the Australian National University, put four empty wine bottles into the ocean just north of Macquarie Island, and within 123 days all four were found on North Canterbury beaches, picked up by different people over a period of 12 days after some stormy weather last February.

They must have drifted some 840 nautical miles or more at a minimum average speed of 14.6 cm per second, but the most remarkable aspect of this experiment is the hundred per cent recovery rate. The pod of four bottles must have travelled together. Why is it that all these bottles seem to be turning up on Canterbury beaches? Obviously it has something to do with the coastal Southland current, which carries surface waters impinging on Fiordland or the coasts near Foveaux Strait towards the north and up the east coast. But maybe there are also human, social, reasons for all the bottle-findings in Canterbury. A long stretch of sandy beaches with a large resident population to keep them under surveillance would contribute to a high discovery rate.

More bottles are likely to be coming ashore on the Canterbury coasts in the next few years. Last summer, another 140 bottles were dropped from the Lindblad Explorer in Drake Passage and a further 169 just south of Macquarie Island. And trails of bottles have been laid from Tasmania to Macquarie and to the Australian bases on the coast of the Antarctic, by research workers from Monash University in Melbourne. More will go into the waters south of New Zealand from this year!s Lindblad Explorer cruises. So beachcombing readers are advised to keep on the lookout. What justification can there be these days for polluting the oceans, and beaches all over the world, with bottles like this? The last word must be with a friendly American whalewatching lady in the Lindblad Explorer who declined to join in any bottle throwing, although interested in the experiments. "Your see,” she said anxiously, “a whale might swallow one." She may be quite right — whales are having a hard time as it is — and a glass bottle would be a very indigestible morsel, even to a sperm whale. Perhaps we should throw the bottles overboard without any corks or messages in them, after all. Or bring them back to port for recycling. But beachcombing, at least on the Canterbury coasts, would then lose some of its appeal.