By Sally Campbell
The world’s oceans take up more than a quarter of the carbon humans are emitting into the atmosphere as carbon dioxide, partially mitigating the greenhouse effect of that carbon. The Southern Ocean accounts for nearly 40 percent of this marine carbon absorption, even though it makes up only one-fifth of Earth’s ocean surface area. There could be enormous consequences for our already warming planet from even a small reduction in the Southern Ocean’s ability to absorb carbon from the atmosphere.
Scientists say this reduction may already be happening, and they suspect that the westerlies in the Southern Hemisphere, which are stronger than their northern counterparts because they blow mostly over open water, are to blame. Records of actual wind speeds, as well as estimates of wind speeds from measurements of atmospheric pressure, provide clear signs that the westerlies in both hemispheres are shifting toward the poles and intensifying. Climate models show that these changes are partly due to global warming, and research is afoot to determine if they are hindering the Southern Ocean’s capacity to extract carbon out of the atmosphere.
Greenpeace’s ships, the Esperanza and Arctic Sunrise are in the Antarctic for the conclusion of Greenpeace’s Pole to Pole expedition. Esperanza has been documenting the dramatic changes this part of the world is undergoing as our planet warms.
The plight of penguins
Independent scientists have recently surveyed chinstrap penguin colonies and released some sobering findings. They found drastic population reductions in many colonies, with some declining by as much as 77% since they were last surveyed almost 50 years ago. They found that every single colony surveyed on Elephant Island, an important habitat northeast of the Antarctic Peninsula, had declined. Climate change and human activity, for example krill fisheries, are key causations for these plummeting populations.
“As wildlife struggles, we all urgently need to speak up for sanctuaries free from harmful human activity not only in the Antarctic, but across the world’s oceans, so marine life such as penguins have the space to recover from human activity and adapt to our rapidly changing climate. To do that, it is imperative that governments agree on a Global Ocean Treaty this year.” Greenpeace has been campaigning for the establishment of three internationally recognised Antarctic sanctuaries, which after being rejected in 2018, are due to be discussed again at this year’s Antarctic Ocean Commission (CCAMLR) meeting in October. These sanctuaries would offer protection for many of the colonies being surveyed.
Record temperatures at base camp
While the scientists were there, the thermometer at an Argentinian basecamp recorded the hottest temperature ever in Antarctica, with the station thermometer reading 18.3C. This was “hotly” followed by another record for the wider Antarctic region, with temperatures exceeding 20C for the first time on Seymour Island. The fact that these elevated temperatures were experienced during the Antarctic leg of the Greenpeace Pole to Pole expedition has meant they have been able to ensure world-wide coverage and links back to the need both to curb emissions to limit climate change, and to secure strong protection for our oceans.
The plight of turtles
Six of the seven marine turtle species are classified as threatened with extinction in the Red List of Threatened Species published and updated regularly by the International Union for the Conservation of Nature IUCN. There are five major hazards that endanger marine turtles today, as well as other less significant hazards; all are the result of human actions. The five major hazards are: fisheries’ impacts, human exploitation of food resources, coastal development, pollution and pathogens, and global warming.
Marine turtles are globally distributed and highly migratory, and regularly inhabit the Atlantic, Pacific and Indian Oceans, as well as the Mediterranean Sea. Aside from adult females which periodically come ashore to nest, and occasional on-shore basking by males and females, marine turtles spend their entire lives at sea. They have unique and complex biological traits and life histories that in some cases are not fully understood.
Because of their highly migratory nature, effective marine turtle conservation requires international and sometimes intercontinental coordination and cooperation. International trade in marine turtles and their products is prohibited under the Convention on International Trade in Endangered Species (CITES).
Research in French Guiana supported by Greenpeace, has revealed that rising ocean temperatures and changing sea currents are forcing Pacific leatherback turtles to travel almost twice the distance to reach new feeding grounds after leaving their nesting grounds.
The Greenpeace report, https://www.greenpeace.org.uk/news/turtles-under-threat-ocean-warming-forces-leatherback-turtles-to-travel-further-for-food/Turtles Under Threat highlights how human activities are endangering global turtle populations. Every year thousands of turtles are caught as ‘by-catch’ in open ocean industrial fishing. Plastic pollution also poses a growing threat. It is estimated that over 50% of all sea turtles have ingested pieces of plastic putting them at a much higher risk of death. Climate change and warming oceans are also putting turtles under increasing pressure, threatening their feeding grounds and breeding habits.
Will McCallum of Greenpeace’s Protect the Oceans campaign, has written: “Sea turtles survived the extinction of the dinosaurs, but they might not survive us. Human activity has put such severe pressure on sea turtle populations around the world that six out of the seven species are threatened with extinction and without urgent action, the situation will only get worse.”
In French Guiana, on the northern Atlantic coast of South America (it borders Brazil to the east and south and Suriname to the west ) the number of eggs laid by sea turtles on beaches is approximately 100 times smaller now than it was in the 1990s. The extra energy expended to find new feeding grounds is likely to reduce the number of eggs they lay each season, shrinking turtle numbers further.
The researchers tagged ten nesting female leatherback turtles on the Yalimapo and Remire-Montjoly beaches in French Guiana to track their subsequent migrations through the North Atlantic. Some swam as far as Nova Scotia in northeast Canada and France to find new feeding grounds. Each of the turtles was given a name. One of them, Frida, was found dead on a beach in Suriname just 120km from her starting point. She had become entangled in a discarded gill net and drowned.
Leatherback turtles migrate north after nesting to reach cooler waters where jellyfish, their prey, are more abundant (see the turtle map). As the oceans warm and currents change, they are being forced to travel greater distances to find new hunting grounds.
This is why we all need to campaign for a strong new Global Ocean Treaty which would pave the way for a global network of fully protected marine sanctuaries covering 30% of the world’s oceans by 2030.
To learn more see:
Ocean witness – the closest thing to being on board
Greenpeace collected footage over the course of their expedition – and are creating a five-part Youtube series telling the story of Pole to Pole and the campaign to protect the oceans over the last year. The first two episodes are online:
Episode 1 (YouTube) – The Arctic – featuring unmissable whale footage, as well as interviews with several of the scientists.
Episode 2 (YouTube) – Turtles – featuring a Q&A with a turtle expert, and interviews with the Aardman director of ‘Turtle Journey’ and our campaigner Edina about turtles and the Amazon Reef.
I know this article paints a gloomy picture but the positive element is that through greater understanding of relationships between populations of species, availability of food in our oceans and environmental threats we can perhaps make more informed decisions about conservation in future that ultimately contributes to our own survival in our complex World.
Sally Campbell, February 2020