What organism forms the base of the entire Antarctic food web?

Antarctic krill Leopard seals Blue whales Antarctic cod

How does Arctic sea ice support the marine food web?

Algae growing on the underside of sea ice forms the base of the food web, feeding krill and other zooplankton Sea ice provides nesting habitat for fish Sea ice prevents predators from reaching fish Sea ice desalinates water, creating ideal habitat

What special adaptations allow fish like the Antarctic icefish to survive in near-freezing polar water?

Antifreeze proteins in their blood that prevent ice crystals from forming in their tissues A thick layer of blubber like marine mammals They generate their own body heat through metabolic activity They migrate to warmer water whenever temperatures drop below 0°C

Why are polar oceans particularly rich in nutrients and marine life?

Cold polar water is dense and sinks, drawing up nutrient-rich deep water through upwelling and mixing Polar regions receive more sunlight than the tropics Polar waters are warm enough for coral reefs Polar oceans have low biodiversity due to extreme cold

How does the formation of polar sea ice affect global ocean circulation?

As seawater freezes, salt is expelled, making surrounding water saltier and denser, causing it to sink and drive deep ocean circulation Sea ice forms a barrier that stops ocean currents from flowing through polar regions The melting of sea ice in summer creates fresh surface water that speeds up circulation Sea ice formation has no significant effect on ocean circulation

What are 'polynya' in polar oceans?

Areas of open water surrounded by sea ice, created by winds or ocean currents, that support concentrated marine life Volcanic vents in Arctic and Antarctic ocean floors Freshwater lakes that form on melting sea ice in summer Trenches found in polar ocean regions

Why are seamounts considered biodiversity hotspots?

Their hard surfaces, currents, and upwelling attract and support diverse concentrations of marine life Seamounts are too deep for life to survive there Seamounts produce warm water that attracts tropical fish to cold regions Seamounts are covered in coral reefs and are identical to tropical reefs

How does the global ocean conveyor belt (thermohaline circulation) affect world climate?

It transports heat from tropical regions to polar regions and vice versa, moderating temperatures worldwide It has no effect on climate because it moves too slowly It only affects ocean temperatures, not atmospheric climate It cools the entire planet by moving cold water to the surface everywhere

What role do oceans play in the global carbon cycle?

Oceans absorb CO2 from the atmosphere and store carbon in marine organisms, sediments, and deep water Oceans release carbon dioxide into the atmosphere, contributing to climate change Oceans have no role in the carbon cycle — it is entirely a land-based process Oceans only store carbon in coral reef calcium carbonate skeletons

How is climate change affecting polar marine ecosystems?

Melting sea ice reduces habitat for ice-dependent species, disrupts food webs, and alters ocean circulation patterns Warmer polar water increases biodiversity uniformly in Arctic and Antarctic regions Climate change has no measurable effect on polar marine ecosystems yet Polar ecosystems are too cold to be affected by a few degrees of warming