Threats to the Antarctic Ecosystem (Cambridge (CIE) IGCSE Geography) : Revision Note

Threats to Antarctica

• Antarctica provides opportunities and resources for people

• However, if they are overused, the ecosystem becomes threatened

Resources

• Antarctica has minerals (like coal and iron) and oil and gas under the ice

• Mining is currently banned by the Antarctic Treaty System and the Madrid Protocol

• Pressure to extract resources may increase in the future due to global demand

  • Drilling and mining could damage fragile ecosystems and disturb native species

Fishing

• The Southern Ocean is rich in marine resources, especially krill and Patagonian toothfish

• Overfishing threatens the balance of the food web, harming predators like whales and penguins

• Illegal, unreported and unregulated (IUU) fishing is a major concern

• Sustainable fishing is possible under strict controls from bodies like CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources)

Tourism

• Antarctica attracts tourists for its wilderness, wildlife, and ice landscapes

• Most tourism is eco-tourism, controlled under the IAATO (International Association of Antarctica Tour Operators)

• Brings economic benefits and increases global awareness about conservation

• However, it risks:

  • Disturbing wildlife (e.g. penguin breeding areas)

  • Spreading invasive species (e.g. seeds on boots or clothes)

  • Pollution from ships and waste

Scientific research

• Antarctica is a natural laboratory for studying:

  • Climate change

  • Glaciology (study of ice)

  • Astrobiology (life in extreme conditions)

• Helps scientists understand past climate and make future predictions

• Research stations can have local impacts (e.g. fuel use, waste), but efforts are made to minimise them

Water source

• Antarctica holds around 60% of the world's freshwater, locked up in the Antarctic Ice Sheet

• As global populations grow and climate change worsens droughts, demand for freshwater is increasing, especially in arid regions like the Middle East and parts of Africa

• In the future, there may be pressure to extract freshwater from Antarctica through:

  • Towing icebergs to water-scarce regions (already tested on a small scale)

  • Melting ice and exporting the water via tankers

Climate change

• Rising global temperatures are causing ice sheets to melt, especially in West Antarctica

• Melting glaciers contribute to sea level rise worldwide

• Warming oceans affect the growth and survival of krill, a keystone species in the marine food web

• Loss of sea ice changes habitats for animals like penguins and seals

• Positive feedback loops (e.g. less ice = more warming) make the situation worse

Impacts of the destruction of Antarctica

• The destruction of Antarctica has both local and global consequences

• Antarctica helps control Earth’s climate; its destruction affects everyone, not just wildlife

Overfishing

• Overfishing of Patagonian toothfish (also known as Chilean sea bass) threatens species that rely on them

• Krill is heavily fished for animal feed and omega-3 supplements

• Krill is a keystone species—its decline affects the entire marine food web (e.g. whales, seals, penguins)

• Overfishing disrupts trophic relationships and can cause population crashes in predator species

• Illegal, unreported, and unregulated (IUU) fishing is difficult to monitor in remote areas

Pollution

• Pollution is when harmful substances are released into the environment, often by human activity

• Sources include:

  • Fuel spills from ships and research bases

  • Plastic waste left by tourists or washed from the sea

  • Microplastics which have been found in the Antarctic snow and krill

• Toxins can enter the food chain, affecting krill, fish, and top predators

• Waste can damage soil and water quality, harming fragile land ecosystems

Tourism

• Tourism to Antarctica for is mostly for recreation, via cruise ships or guided tours

• Antarctica sees over 50,000 tourists a year, mostly to the Antarctic Peninsula

• Tourists can disturb wildlife, especially during breeding seasons (e.g. penguins abandoning nests)

• Risk of introducing invasive species via seeds or microbes carried on clothing and equipment

• Tour ships use heavy fuel oil, contributing to air and marine pollution

• Tourism is regulated by IAATO (International Association of Antarctica Tour Operators) to minimise impact

Ozone layer depletion

• Ozone layer depletion is the thinning of the ozone layer in the stratosphere, caused mainly by CFCs (chlorofluorocarbons)

• The ozone hole forms every spring over Antarctica, letting more UV radiation reach the surface

• Increased UV exposure harms phytoplankton, the base of the marine food chain

• Less phytoplankton = less krill = less food for marine predators

• UV rays can also damage the DNA of terrestrial organisms, including microbes and mosses

Food web collapse

• Krill populations are falling due to warming seas and less sea ice (which krill need for breeding)

• If krill decline, species that depend on them—whales, seals, penguins, and fish—also decline

• This is an example of a bottom-up trophic cascade—when a change at the base of the food chain affects the whole ecosystem

• Some species may go extinct if they cannot adapt or find new food sources

Biodiversity loss

• Many Antarctic species are endemic—they live nowhere else on Earth

• Loss of ice habitats threatens Adélie penguins, emperor penguins, and ice-dependent seals

• Invasive species, introduced by humans, can outcompete native life (e.g. grasses or insects carried on tourist clothing)

• The terrestrial ecosystem is already low in biodiversity, so any loss has a larger impact

Scientific research disruption

• Antarctica is a key place for climate science, atmospheric research, and glaciology

• Destruction of ecosystems makes it harder to study natural conditions

• May affect data records and long-term monitoring of Earth systems

• The loss of pristine environments reduces the opportunity to study how life survives in extreme conditions

Freshwater impact

• Melting Antarctic ice adds large amounts of freshwater to oceans

• This affects the salinity (saltiness) of seawater, which changes ocean currents and climate feedback loops

• This could result in an increase in the number of severe weather events that occur in other regions of the world, such as storms, floods, and droughts

Global climate system

• Ice sheets reflect sunlight (high albedo), helping to keep Earth cool

• If the ice melts, darker ocean water absorbs more heat, increasing global warming

• Melting Antarctic ice contributes to sea level rise, threatening low-lying coastal areas worldwide

• Disruption to the thermohaline circulation (deep ocean currents) affects global weather patterns and rainfall distribution