The Antarctic Peninsula and the Scotia Arc, including the South Orkney Islands, are among the most rapidly warming parts of our planet. Air and ocean temperatures have increased, some ice shelves have retreated or collapsed, most glaciers have also retreated, and seasonal pack ice is generally much reduced. This has important consequences for the wildlife, including Adélie, chinstrap and gentoo penguins.
Dr Phil Trathan from the British Antarctic Survey (BAS) has been studying Adélie penguins, a species of the pack ice, for the past 18 years. Based on recent published work, and on his own experience, Phil believes that Adélies are declining in most parts of the Peninsula and the South Orkney Islands.
That’s why WWF now supports his vital research, helping BAS to study the foraging behaviour of these penguins in an attempt to identify their feeding grounds – and to monitor the effectiveness of the South Orkney Islands Marine Protected Area.
This MPA was designated in 2009 by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). It was created because of its unique biological and oceanographic features, and because it’s an important area for Adélie penguins after they complete their breeding. Indeed the benthic (ocean-floor-dwelling) fauna of the South Orkneys is thought to be more biodiverse that the Galapagos.
It was the first MPA located within the CAMLR Convention Area, and the first anywhere in the world located entirely within the High Seas. In recognition of this achievement, and its commitment to developing a network of MPAs across the Southern Ocean, WWF awarded CCAMLR its highest accolade, the ‘Gift to the Earth’ award.
I caught up with Phil Trathan last week to find out how this season’s fieldwork went:
“Over the past few years we’ve been tracking penguins from a number of different sites in the South Orkney Islands, and this year we planned to do the same,” Phil told me. Unfortunately, the best laid plans of ice, men and penguins often go astray!
“The satellite tracking data we’ve collected over a number of years, showing where Adélie penguins forage, highlights the importance of the MPA for Adélie penguins. This year we’d planned to collect more data to see if other Adélie colonies also use the area of the MPA after breeding.
Adult penguins lose body weight over the breeding season, so they need to regain condition after breeding is complete and before their annual moult takes place. The moult for penguins is an energy-intensive period as they cannot feed themselves while shedding their feathers. They lose all their feathers and grow their new plumage, meaning they have to have good energy reserves. It means feeding well between breeding and moult is crucial.
“The pack ice this year was more extensive than it has been over the past few years and this hindered our ship’s progress towards the islands in late January. Because of this, we couldn’t get in to one of the field sites where we’d planned to deploy some of our tracking devices, as the ice made it too difficult for the ship I was on to get to the colonies.
But we did manage to track other Adélies from our base on Signy Island, and as you can see, these show that the area covered by the MPA continues to be vitally important for them to feed in.”
Collecting this sort of information about where Adélie penguins feed before they moult is important, as it will help CCAMLR justify the continuation of the MPA when it comes up for review in 2014.
‘The unusual pack ice conditions may also have had other effects this year. The breeding success of chinstraps and gentoos has been lower than normal, whereas the breeding success of Adélies, creatures of the pack, has been about average.
Both gentoos and chinstraps normally avoid the pack ice, so this fits with our understanding of the preferred feeding habitat of these species of penguin.”
Understanding the foraging behaviour of Adélie penguins is also particularly important because the main food for these penguins, Antarctic krill, is the target of a regional fishery.
Phil told me that “the fishery is well regulated by CCAMLR but new fishing technologies and new markets for krill products (such as krill oil capsules) mean that catches are increasing. CCAMLR will need to develop new management methods to ensure there is no impact of fishing on the wildlife that feeds on krill.”
Also known as the ‘krill convention’, CCAMLR is an international treaty which was agreed in 1980 in response to concerns that unregulated krill fishing in the Southern Ocean could harm marine ecosystems, particularly seabirds, seals, whales and fish that depend on krill for food.
It is critically important to ensure that krill fishing is managed responsibly and sustainably under the CCAMLR convention.
As Phil and I both know, the Antarctic is a notoriously challenging, but rewarding, place to work, and every year can be completely different from the last. Despite the recent decreases in pack ice, there is still considerable natural variability, making access difficult in years like this.
So Phil will just have to return next year with the remaining satellite tracking devices – back to the land of ice and penguins.