Those who have the privilege to have seen South Georgia with their own eyes will remember the island as a wildlife paradise. Seals, penguins, flying seabirds – they are all there. The colonies are hugely impressive.
And there have been good news about the conservation status of South Georgia in recent years. The reindeer that Norwegian whalers had introduced from 1911 were culled until 2014. In South Georgia, the reindeer population had a density of up to 85 animals per square kilometre, in contrast to about 5 per sq km in Spitsbergen. It does not surprise that the vegetation in South Georgia suffered severely from the constant trampling and grazing from thousands for reindeer in those areas where they existed. This was evident when you compared those parts of South Georgia where reindeer roamed the tussock grass with other areas where they never existed. The eradication project gained priority when the ongoing retreat of glaciers threatened to enable reindeer to migrate to other parts of the island which had been naturally closed of until now. Wherever possible, reindeer were herded and slaughtered; elsewhere, they were shot by hunters. The last ones were culled in 2014. Since then, the vegetation and accordingly many bird species associated with the tussock gras communities can return to their original habitat in those areas formerly inhabited by reindeer.
Getting rid of rats was another and much larger challenge. These came also with the whalers to the island. They thrived soon in many areas – a disaster for many ground-breeding seabirds, meaning pretty much all of them (there are no trees on South Georgia). Rats take eggs and chicks from nests and burrows and they don’t even hesitate to have a go at chicks from large albatrosses.
In a herculean effort that lastet over several years, the South Georgia Heritage Trust has eradicated rats on South Georgia. The evaluation phase is still going on, but years of monitoring have not shown any traces of rats still being present on the island. Birds such as the South Georgia pipit which had been restricted to small off-lying islands for many decades soon started to re-establish themselves on the main island.
The recovery of whale and seal populations after centuries of intense catching and hunting is also good news. Today, thousands of Fur seals crowd South Georgia’s beaches again. Some whale species will need centuries to return to pre-industrial levels if they ever do, while others, noticeably the Humpback whale, make a swifter return. The overall development is positive.
But all these good news and successes don’t mean that everything is as it should be. Bycatch in fisheries has been an issue for decades, being the reason for dramatic declines of many seabird species not only in South Georgia, but in many areas of the world. This includes iconic species such as the Wandering albatross and many of its close relatives. Also here, there have been regional improvements: in South Georgia’s waters, strict regulations have brought major improvements. Here, bycatch does not have a significant effect on populations anymore, birds drowning on longlines are rare exceptions today. That is the good news. The bad news is that fishing vessels elsewhere in the Southern Ocean (or elsewhere, for that sake) operate under much less strict regulations and often illegally. And many seabirds travel thousands of miles on their foraging trips. Regional protection will not be able solve the problem.
As a result, in spite of regional successes bycatch is still considered the one big main threat for many seabird populations. Also on South Georgia, several albatross species are still declining strongly – in a state which is already considered anything but stable and healthy. Species including Wandering, Black-browed and Grey-headed albatross are all listed on the IUCN list at various levels of risk. And all of them are still losing individuals at an alarming rate, as is confirmed by recent surveys..
Wandering albatross on nest on Bird Island, South Georgia.
The number of Wandering albatrosses breeding on South Georgia has declined by 18 % in just 11 years, from 2003/04 to 2014/15. Speaking in absolute figures, only 1278 were left out of 1553 in the beginning of the above-mentioned period. Black-browed albatrosses went through a very similar development with a loss of 19 %. For Grey-headed albatrosses, the situation was even much more dramatic with a loss of a stunning 43 %.
And it is not that this development started at a healthy level in 2003/04. Populations have declined at least since the 1970, when scientists started to monitor them more regularly. Today’s colonies are just a shadow of what they were when South Georgia and the Southern Ocean were still untouched by man, before whaling and sealing started. Sally Poncet and her co-authors consider bycatch in fisheries still the main threat for South Georgia’s albatrosses.