Antarctica's Pollution Victims: Animals In Danger

Antarctica is a continent devoid of permanent human settlement, yet human activities have had a significant impact on its environment. Pollution from human activity poses a great risk to the sensitive Antarctic ecosystem, which includes penguins, whales, seals, and various marine species. The sources of pollution in Antarctica are diverse and include oil spills, sewage discharge, plastic pollution, and the release of chemicals such as chlorofluorocarbons (CFCs) that contribute to ozone depletion. These pollutants have far-reaching consequences, affecting not only the wildlife but also the hydrology, climate, and surrounding oceans of the region.

Plastics in the Southern Ocean

Antarctica is the most remote place on Earth, but it is not protected from plastic pollution that accidentally enters the ocean. The Southern Ocean, which surrounds Antarctica, is warming faster than other oceans and is becoming more acidic. Thus, Antarctic marine animals that have lived in an untouched, stable environment for millions of years are now being exposed to plastic pollution and human-caused climate change.

Sources of Plastic Pollution in the Southern Ocean

The Southern Ocean contains plastics of all shapes and sizes, from lost fishing nets to plastic bottles, and microscopic particles. While some of this pollution is a result of human activity in Antarctica, such as scientific research or tourism, most of it comes from outside the continent. Plastics can travel exceptionally long distances across the ocean. Scientists now believe plastics can pass through the strong current surrounding Antarctica, with microscopic plastic particles carried by subsurface currents, by sticking to seaweed, or within marine animals that have eaten plastic.

Impact of Plastics on Antarctic Animals

It is easy to see the harm that larger plastics cause to ocean animals. For example, animals such as seals and penguins can get caught in lost fishing nets. The harm caused by microplastics or nanoplastics is more difficult to see. However, small animals such as zooplankton, which are food for larger animals, may mistake tiny plastic pellets for food. As sea ice has high concentrations of plastic pollution, its melting can be worrying for zooplankton like Antarctic krill that feed on sea-ice algae.

Addressing Plastic Pollution

The British Antarctic Survey (BAS) is a United Kingdom-based organization dedicated to Antarctic research that implements several measures for sustainable research on the continent. All waste produced by the BAS on Antarctica, except for sewage and food waste, is removed from the continent. BAS has also installed a biological waste treatment plant and incinerates food waste and sludge.

Plastic pollution, ocean warming, and ocean acidification are known to impact the development of Antarctic krill, as well as their ability to lay healthy eggs and their overall behaviour. It is important to understand how Antarctic marine animals will react to these environmental changes to protect our oceans in the future.

Ozone depletion

The ozone hole is caused primarily by the release of chlorofluorocarbons (CFCs) into the atmosphere. CFCs are long-lived chemicals used in refrigeration and aerosol sprays. While they circulate without issue in the troposphere (the layer of the atmosphere closest to the Earth), when they reach the stratosphere, UV light causes them to break down and release chlorine, a highly reactive atom that catalyses ozone destruction. The ozone hole opened the world's eyes to the global effects of human activity, specifically the use of ozone-depleting chemicals.

The effects of the ozone hole are felt across the Antarctic ecosystem. With reduced ozone protection, more UV radiation reaches the Earth's surface and penetrates ocean waters. This has been shown to harm marine plants and animals in the region. For example, researchers have found evidence of increased UV radiation damaging the DNA of icefish eggs and larvae, which could ultimately reduce their survival rates. Organisms that breed in spring, such as icefish and krill, are particularly vulnerable as they release their eggs into ocean waters during the peak of the ozone hole.

The international community has taken steps to address ozone depletion through agreements like the 1987 Montreal Protocol, which aims to phase out the production of ozone-depleting chemicals. While some improvements have been observed, models suggest that it will take until the middle of this century for ozone levels to return to pre-1980 concentrations.

Ocean acidification

The ocean absorbs carbon dioxide and other gases from the atmosphere. The amount of carbon dioxide in the atmosphere is increasing due to human activities, such as burning fossil fuels. The ocean has absorbed as much as 40% of the extra carbon dioxide produced by humans, and almost half of all the carbon absorbed by the ocean has taken place in the Southern Ocean.

When carbon dioxide dissolves in seawater, chemical reactions cause the ocean to become more acidic. Ocean acidification makes it difficult for corals to build their skeletons and for marine organisms to build and maintain their shells. The polar regions are particularly vulnerable to the effects of ocean acidification.

Acidification threatens Antarctic ecosystems, with potential impacts on global ocean health and human industries. As the Southern Ocean continues to become more acidic, the impacts will be felt across the ecosystem, from Antarctic clams to penguins, seals, and human fisheries.

In conclusion, ocean acidification poses a significant threat to the Antarctic marine ecosystem, with potential consequences for both wildlife and human industries. Further research and mitigation efforts are necessary to address this pressing issue.

Climate change

Antarctica is one of the coldest and most inhospitable places on Earth, yet it hosts a wealth of biodiversity. However, the effects of climate change are threatening the survival of many species. The Antarctic Peninsula is one of the fastest-warming places on the planet, with air temperatures rising by nearly 3°C since 1951. This has caused the ice cover around it to drop by 20% since 1979. The ocean west of the Antarctic Peninsula has also warmed by more than 1°C since the 1960s, which has severe implications for wildlife.

Sea ice is crucial for Antarctic ecosystems, as most organisms' life cycles are attuned to its seasonality. It provides a feeding ground for krill, a keystone species in Antarctica, which in turn provides food for many other animals, including penguins, seals, and whales. However, the density of krill populations has declined by 80% since the 1970s due to factors such as over-harvesting, sea ice loss, and ocean warming and acidification. This decline in krill has contributed to the decline of several penguin species, including Adélie and chinstrap penguins.

Some species, like the Adélie penguin, are dependent on sea ice for foraging, resting, moulting, and migrating. As sea ice retreats, these penguins are having more trouble finding food, and fewer chicks are surviving to adulthood. Additionally, the melting of perennial snow and ice covers has resulted in increased colonisation by plants, further altering the habitat.

The loss of sea ice also affects species that rely on it for reproduction and foraging, such as Crabeater, Weddell, Ross, and Leopard seals. On the other hand, species that do not depend as heavily on ice, such as Southern Elephant and Fur seals, have seen increases in population.

The warming of the Antarctic Peninsula is not just restricted to the land but can also be observed in the Southern Ocean. Upper ocean temperatures to the west of the Antarctic Peninsula have increased by over 1°C since 1955. This warming is causing glaciers to retreat and, in some cases, collapse completely. The loss of ice contributes to rising sea levels, which could have global consequences.

The effects of climate change on Antarctica's wildlife are complex and vary depending on the species and their specific adaptations. Some species may even benefit from the changing conditions in the short term, as the expansion of ice-free areas provides more space for breeding. However, the rate at which the physical environment is changing appears to be faster than the rate at which Antarctic organisms can adapt, and iconic species such as emperor penguins are at risk of extinction.

Hunting and fishing

Antarctica's wildlife is incredibly vulnerable to the effects of human activity, including hunting and fishing.

Hunting

Hunting for whales and seals drew people to Antarctica in the early 1800s. Within a few decades, these activities had caused a major crash in wildlife populations. By 1830, the Antarctic fur seal was on the verge of extinction in many locations.

Large-scale whaling in Antarctica began in the early 1900s, with the Southern Ocean providing 50% of the world's catch by 1910. Whalers would target the most profitable species, deplete their stocks, and then move on to another species. This cycle repeated until the International Whaling Commission (IWC) first met in 1949. Blue and humpback whales became fully protected in the 1960s, and protection was extended to fin and sei whales in the 1970s. In 1986, the IWC decided to suspend all commercial whaling.

Fishing

Fishing is the only large-scale commercial activity currently taking place in the Antarctic Treaty area. Major fisheries worldwide have faced over-exploitation, and without proper controls, the Southern Ocean will face the same fate. The major negative effects of fisheries include:

• The potential for overfishing of target species
• Effects on predator populations that depend on the target species as a food source
• Mortality of non-target species caught by fishing equipment
• Destruction of habitats

Long-line fishing, for example, is a particular risk to albatrosses. The Australian Fisheries Management Authority limits the fishery around Heard and Macquarie Islands to trawling to minimise the impact on seabirds.

Overharvesting of fish and krill has altered populations since the 1950s, and it remains a large concern. Krill fishing, in particular, needs to be closely monitored and controlled to ensure whales, penguins, and other wildlife are protected.

Invasive Species

Human activity has also led to the introduction of invasive species, threatening native wildlife. Rats, for example, are a particular threat to nesting seabirds, whose eggs they eat.

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