From Krill to Whales: Conserving the Southern Ocean
By Andrew Millham
Location: Essex, UK
Andrew Millham is a nature writer, environmental science student and Media Officer for ReservaYLT.
If you charter a ship and travel south, you will reach a sea like no other: the Southern Ocean. It is host to large icebergs inverting unpredictably and the treacherous Drake Passage, where the South Pacific and Southern Ocean meet to form the roughest area of water in the world. For me, this region stirs up images of Sir Ernest Shackleton’s incredible survival feat in 1914, when his ship ‘Endurance’ became trapped in sea ice and he sailed a 23 ft open lifeboat 800 miles across the region, eventually reaching safety in South Georgia.
Encircling the Antarctic continent, this ocean makes up the southernmost waters of the World Ocean. To get a sense of scale, the icebergs that form each year in the Southern Ocean hold enough fresh water to meet the needs of every person on earth for several months – but, like all polar regions, this ocean is changing. Despite its remoteness, this pristine ecosystem is being threatened by pollution (washed up by ocean currents), and climate change.
“Antarctica’s terrestrial ecosystem is almost entirely made up of penguins and seabirds, but most of the continent is devoid of life – truly a polar desert. One would therefore be forgiven for assuming that the Southern Ocean is similarly sparse, with the cold waters acting as a poor host for life. ”
This is far from the truth. The waters are home to a great variety of life, ranging in size from phytoplankton to blue whales, forming a dense and complex aquatic ecosystem. The Antarctic Circumpolar Current (ACC) is an ocean current that flows clockwise around Antarctica, blocking warmer waters and allowing the continent to maintain its enormous ice sheet. This chilly current meets the warmer waters of the subantarctic and because warmer water is more buoyant, it causes upwelling of warmer nutrient-rich water – this meeting is called the Antarctic Convergence. Upwellings are rich with phytoplankton (microscopic marine algae), which provides food for arguably the most important creature in the Southern Ocean – krill.
Krill are shrimp-like filter feeders- a cornerstone of the entire ocean ecosystem. They are eaten by fish, seals, and squid, which are subsequently eaten by penguins, elephant seals and leopard seals, which are finally eaten by baleen whales, smaller toothed whales, sperm whales and blue whales – the largest mammal on the planet! Krill underpin this entire food web so if they disappear, every creature that depends on them will too.
Credit: Brett Wilks
Unfortunately, climate change and warming waters are responsible for melting the ice that is home to the algae and plankton krill. These small crustaceans are being forced to retreat further towards the continent. If warming continues at the current rate, they will reach land and have nowhere left to go. As well as being threatened by climate change, krill is caught by the boatload and used as food for fish farms. Catching krill is not the only issue, pollution from fishing vessels and oil leaks also threaten to damage ecologically vulnerable areas. ‘Krill Oil’, especially popular in Japan and China, is another lead contributor to their decrease in numbers – the oil is high in Omega-3 and has a high antioxidant content. When comparing the benefits of krill oil to its drawbacks, such as the amount of ecological carnage it causes, I do not believe that these health benefits warrant the destruction of one of our last untouched wildernesses. On a positive note, large krill fishing firms have recently shown their support for Antarctic marine reserves, following an influential Greenpeace campaign.
In recent years, conservatory action has been widespread in the region. The Antarctic and Southern Ocean Coalition was founded in 1978 by 30 non-government global conservation organisations (including WWF) that would defend the integrity of the ocean ecosystem and stop human activities from encroaching on it. This union supports the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), who aim to ‘maintain existing ecological relationships and to achieve conservation while allowing the ‘rational use’ of living resources, like regulated fishing’. A key aim of theirs is to protect 30% of the Southern Ocean by 2030; that is equivalent to 10.8 million square kilometres, which would be a tremendous achievement. These groups have set up a network of marine protected areas (MPAs) which protect fragile nursery habitats and the vulnerable species mentioned previously – similar to a national park on land. In 2016, a monumental 1.55 million square kilometres of the Ross Sea was protected which includes a ‘general protection zone’, ‘special research zone’ and a ‘krill research zone’ where the ecosystem is being studied in depth. CCAMLR are currently considering proposals for the Weddell Sea, East Antarctica and the Antarctica Peninsula, which is very encouraging.
Since November 2006, the Antarctic and Southern Ocean Coalition has identified at least 25 shipping incidents in the Southern Ocean which have required some level of emergency response. Incidents range from groundings and collisions with ice, to besetment (entrapment) in ice, mechanical failures, and on-board fires. Some of these accidents have resulted in oil spills which damage the environment. As shipping traffic increases in the Southern Ocean, the chance of further accidents also rises. In 2011, there was a ban on the use and carriage of heavy fuel oil in polar waters. More recently, the coalition welcomed the adoption by the Members of International Maritime Organization (IMO) of a ‘Polar Code’ for shipping, which from 2017 will introduce mandatory safety and pollution prevention measures for cruise ships and large cargo ships (over 500 gross tonnes).
The number of tourists visiting Antarctica annually has grown from around 300 in the early 1970s to over 20,000 today. Subsequently, seven independent tour companies operating in Antarctica took it upon themselves to create an organisation known as International Association of Antarctic Tour Operators (IAATO) in 1991. The purpose of IAATO is to ensure safe, responsible, environmentally sensitive tourism in the fragile Antarctic ecosystem. It is a self-regulating organisation within the private sector travel and expedition industry and has strict bylaws and codes of conduct – helping to standardise environmental protection measures in the region. For example, one rule states that you should ‘not dispose of litter from ships into the ocean or on land’. This is one of such guidelines that have allowed tourism to continue sustainably.
For the moment, it appears that the Southern Ocean is in safe hands because organisations like these are committed to fighting its corner. Preserving the region and the diverse wildlife within it would be a fantastic legacy for the future generations and ultimately, a triumph in the field of ocean and wildlife conservation. With the appearance of conservation organisations and MPAs, it is comforting to think that one of our last wildernesses is being preserved, even if the ice is not.