Wildlife of South Georgia, 10 January 2007
CHRIS BRADING
Islands hold a fascination for me, and South Georgia is particularly interesting as it is very remote, situated in the South Atlantic just within the Antarctic convergence and 800 miles from the nearest land, the Falkland Islands. Geologically it lies on the South Scotia Arc, the largely submarine ridge that runs in a continuous curve from the tip of South America through South Georgia, South Sandwich and the South Orkney Islands to re-emerge as the Antarctic Peninsula. South Georgia is ruggedly mountainous reaching 2934 metres at the highest point, Mount Paget. The rocks are similar to those found in South America but the island is heavily glaciated and the south coast is almost inaccessible. The north coast is less severe with several gaps leading to sheltered bays and plains where vegetation has developed. The glaciers have retreated a long way over the past 50 years. Situated between 54º and 55º south in the track of the South Atlantic depressions, it is mostly cold, wet and very windy. However in summer the days are long and can be warm and sunny.
South Georgia was first sighted in 1675 by a British merchant, but the first recorded landing was in 1775 by Captain Cook, who claimed it for King George III. He reported on the rich shallow seas supporting an abundance of bird life, seals and whales. The sealers arrived in 1786 and by the end of the 19th century had hunted the fur seal almost to extinction. As that industry collapsed a second wave of destruction began with whaling. Carl Anton Larsen was a sealing captain but also one of Norway's greatest explorers. He had already made two voyages to the Weddel sea in the 'Jason', when in 1901 he was invited to join the Swedish South Polar Expedition 1901-3 led by Otto Nordenskjold, as captain of the expedition ship 'Antarctic'. Larsen spent two months during the first winter exploring South Georgia. He saw the potential for whaling and in 1904 returned to South Georgia and set up the whaling station at Grytviken. The industry was still in full swing when I first visited Grytviken in 1961, but the signs of decline were already there and catchers had to hunt up to 200 miles away. Grytviken closed in 1962, and briefly reopened a year later, but all whaling ceased in 1965. A total of 175,250 whales had been processed and the once abundant seas around South Georgia were empty.
South Georgia has historically also been associated with polar exploration. In 1914 Ernest Shackleton set off from South Georgia on his ill fated 'Endurance' expedition. Months later he returned to the island having sailed 800 miles from Elephant Island in a lifeboat across the stormiest ocean in the world. He landed on the inhospitable south coast and had to cross the unmapped glaciated mountainous spine of the island to get help. In 1921, on another expedition, he died at Grytviken and is buried in the whalers' cemetery.
I returned for a few days in February 2005 on an expedition cruise ship. For the naturalist the island is a paradise. There are no airfields so going by sea is the only option. The nutrient-rich sea is full of phytoplankton and krill, the bottom of the food chain that supports all life. The air is full of sea birds from the giant wandering albatross, the immaculate light-mantled sooty albatross, cape pigeon (pintado petrel), numerous other petrels and prions down to the tiny delicate dancing Wilson's and black-bellied storm petrels. Whales were also seen but not too many so each sighting would cause a flurry of excitement and much clicking of cameras. As you approach the island the flocks become denser as this is one of the few places where they can breed. Seals and penguins were also in evidence.
The whaling stations are derelict with the exception of Grytviken, where much has been demolished but some parts have been restored and a museum set up in the manager's old house to cater for today's tourists. The church, built by Anton Larsen, has also been restored through the efforts of his grandsons. The station is only manned during the summer months but British Antarctic Survey (BAS) still maintains a permanent presence across the bay at King Edward Point. Today they monitor the fishing industry and carry out ecological research. The only other inhabited place is on Bird Island, which has a small BAS research station.
We landed on a beach called Gold Harbour. There must have been 50,000 pairs of king penguins breeding on the narrow coastal strip. King penguins are sub-Antarctic and do not go into the polar region. Although most eggs are laid in November the chicks take about 15 months to fledge fully. Consequently one can observe the whole breeding cycle from courting pairs, egg laying and incubation, through all stages of chick growth to the full-grown 'woolly' penguin and subsequent moult to the adolescent adult. The first explorers thought that the full-grown 'woolly' chick was a separate species. Scattered along the beach were literally piles of elephant seals, huddled together for warmth while undergoing their annual moult. The females had already given birth, weaned the pups and remated. The large fat pups were lying around, abandoned, but still growing from the blubber laid down from their mother's rich milk. Soon they would have to go to sea and fend for themselves.
Tussock grass is the dominant plant on the coastal strip and it is the home of many breeding species. There were thousands of fur seals lying amongst the tufts closest to the shore. From near extinction in 1961, when I was first there, they have bounced back to a population of several million. I never thought I would hear a marine biologist advocate a culling programme but they are so numerous that they are in danger of destroying the habitat, which is also essential for nesting Gentou and chinstrap penguins and many other species. Unlike the comatose elephant seals, the fur seal is very fast and quite aggressive with very sharp teeth, as one of my companions found to his cost!
Away from the coastal strip the ground rises quite steeply and the vegetation changes, with rushes and grasses and large areas of the colourful greater burnet. The native flora has only 18 flowering plants and seven ferns among the vascular plants, and about 125 mosses, 85 liverworts, 200 lichens, and a number of fungi. In the flatter boggy areas, peat bogs up to several metres thick have developed. Only a few areas have been systematically researched and no doubt many species remain to be discovered, particularly among the bryophytes. A number of introduced species have also survived, mainly around the old whaling stations. The steeper slopes and cliffs provide nesting spots for many species of sea bird and the numbers are staggering. It is estimated that there are 22 million Antarctic prions, 3.3 million common diving petrels, 2 million white-chinned petrels, 600,000 Wilson's storm petrels, and 10,000 Antarctic terns to name but a few.
There were no land mammals on the island until man introduced them both by accident and by design. Larsen introduced reindeer for meat and sport and today there are three separate thriving herds. The only surviving accidental introductions are the common rat and house mouse. The latter is only hanging on round the inhabited areas of Grytviken, but the rat has spread out and has caused devastation amongst the ground-breeding birds. Some once abundant species, such as the indigenous South Georgia pipit, can now only be found on the offshore islands.
We landed at Fortuna Bay at a point where a stream formed a wide shallow pool. It was full of young fur seal pups cavorting with each other and obviously having fun. We followed the stream across one of the plains towards the source of one of the many glaciers. At first the vegetation was lush and we passed another large king penguin rookery, then as it widened out we saw a large herd of reindeer. The vegetation gradually thinned as we crossed various glacial features from moraines to outwash sands and gravels. The sides of the valley rose steeply and the first 100 feet or so were devoid of any significant vegetation. The glacier has retreated a long way in recent years and the vegetation has not had time to recolonise.
When Shackleton landed on the south coast and had to cross the island he came down this glacier and found himself too far west in the wrong valley. He had to travel a further three and a half miles and cross over a col at 1500 feet to reach the whaling station at Stromness. We repeated that walk. The terrain was very bleak and the rock frost shattered with very little vegetation on the exposed slopes open to the prevailing westerly winds. The view from the col was breathtaking and one could not but wonder how Shackleton must have felt to see the whaling station after his terrible endeavours. Following a steep descent the valley opened out on to grassy slopes with mossy streambeds culminating in areas of moss and peat bog. In one of the many pools I found the indigenous duck I was hoping to see, the South Georgia pintail.
We moved westward to the Bay of Islands and visited another glacial valley known as Salisbury Plain. However, the highlight of the day was a landing on Prion Island. The air was full of sea birds with Antarctic terns screaming above our heads at the landing beach. We climbed through the tussock grass to the flat summit where many birds were nesting but dominating all were the wandering albatrosses. Some were sitting on nests. Some large chicks were waiting patiently for a parent to return with food, but the most unforgettable sight was a large male with a 12-foot wingspan displaying to two females. We must have been transfixed for half an hour by this magnificent spectacle. Albatrosses of many species were flying low over our heads including wandering, black-browed, grey-headed and my favourite the light-mantled sooty albatross. The latter were performing a courtship display, flying in perfect formation. I was so mesmerised that I nearly missed the small, insignificant but very rare indigenous South Georgia pipit hopping about among the tussock grass. This is the southernmost of all songbirds. It was once common on the mainland but was predated by introduced rats and is now only found on the offshore islands.
Sadly this was our last landing. As we sailed away the clouds came down and the ship ploughed into yet another force 12 (hurricane force) gale, something you must expect if you want to visit this jewel of an island in the southern ocean.