Polar and Deep Ocean Biology: Ecosystems, Adaptations, and Climate Impact

What is the main focus of Gateway Antarctica?

It is a center in the School of Earth and Environment focused on Antarctica.

What are the primary differences between Antarctica and the Arctic?

Antarctica is a continent with no bears, while the Arctic is an ocean that has polar bears.

How many species of penguins exist in the world?

There are 18 species of penguins in the world.

Which region has the highest diversity of penguin species?

New Zealand has the highest penguin diversity.

What is the current trend regarding Antarctic sea ice?

Antarctic sea ice is decreasing, contrary to the belief that it is stable.

Why is Antarctic sea ice considered more stable than Arctic sea ice?

Antarctic ice is over land, which has larger temperature fluctuations and can be heated more easily than water.

What is a positive feedback loop in the context of ice melting?

A small amount of ice melting into water causes the water to warm more easily, leading to further ice melting.

What is the 'freezer effect' created by Antarctic sea ice?

The ice that grows around Antarctica doubles the land size of the continent, helping to regulate global temperatures.

What are 'pagophilic' organisms?

Organisms that are ice-loving and depend on sea ice for their habitat.

What is the difference between pack ice and fast ice?

Pack ice is seasonal and disappears at certain times of the year, while fast ice is connected to land and present all year round.

What are the two types of polynyas?

Latent heat polynyas, formed by katabatic winds, and sensible heat polynyas, formed by upwelling water.

What role do polynyas play in the Antarctic ecosystem?

Polynyas support high phytoplankton productivity and biodiversity, attracting animals like penguins and seals.

What is the primary food source in the Antarctic food web?

Krill is the dominant species, with silverfish also playing a significant role.

What are the two main types of krill mentioned?

Crystal krill and Antarctic krill.

How do seals use bubbles in their hunting strategy?

Seals blow bubbles to scare fish hiding in the sea ice.

What is the significance of the Cold Dense Water around Antarctica?

It travels around the world, including to the Arctic, influencing global ocean currents.

How does Arctic productivity differ from Antarctic productivity?

Arctic productivity starts at the edges of ice and follows changing ice extent, while Antarctic relies on polynyas.

What adaptations do Arctic pinnipeds have for survival?

They are completely white to hide from predators like polar bears.

What is unique about polar bears in relation to marine mammals?

Polar bears are the only bears considered marine mammals.

What are the two 'true' Antarctic penguin species?

The Emperor and Adélie penguins.

What is the impact of climate change on polar regions?

Climate change affects both regions differently due to their geographic differences.

What is the role of silverfish in the Antarctic ecosystem?

Silverfish are more nutritious than krill and are often found under fast ice, making them easier for predators to access.

What is intra-specific competition in penguins?

It refers to competition among penguins for foraging distances and resources.

What is the significance of the Antarctic food web structure?

It is dominated by krill, which is critical for the ecosystem's functioning.

How do Weddell seals differ in their foraging behavior?

Weddell seals do not forage for the first 7-8 weeks of their pup's life.

What happens to Arctic phytoplankton blooms during the seasons?

In spring, diatoms bloom at the edges, while coccolithophores bloom in summer when there is less ice.

What is defined as deep sea?

Waters below the mesopelagic zone.

What percentage of the ocean area is considered deep sea?

93%

What is the temperature at 1000 m depth in the ocean?

About 3.5°C.

What are the divisions of ocean depths?

Epipelagic (0-200 m), Mesopelagic (200-1000 m), Bathypelagic (1000-4000 m), Abyssopelagic (4000-6000 m), Hadopelagic (6000 m to 11,000 m).

What happens to phosphate and nitrate concentrations with depth?

They peak at 500-1000 m deep before gradually decreasing.

What is the great ocean conveyor?

A deep circulation pattern that replenishes oxygen in ocean depths.

How does fish diversity change with depth?

Fish diversity increases with depth, despite greater biomass near the surface.

What is the oxygen minimum zone?

A layer in the mesopelagic zone with low oxygen due to bacterial respiration of decomposing organic matter.

What adaptations do organisms have to cope with increased pressure in the deep sea?

Some lack swim bladders, have reduced skeletons, weak musculature, or hard outer shells.

How does pressure change with depth in the ocean?

Pressure increases by 1 ATM for every 10 m of depth.

What are some adaptations of mesopelagic organisms?

Color, size, sense organs, photophores, bioluminescence, large mouths, and migrations.

What is the significance of photophores in mesopelagic fish?

They assist in countershading and can be used for mating recognition and prey attraction.

What is the role of the nautilus in the deep sea?

A cephalopod that retains a gas-filled shell and captures food with tentacles.

What are characteristics of bathypelagic organisms?

They are typically small, black, with reduced musculature and long hinged jaws.

What is the difference between migrating and non-migrating mesopelagic fish?

Migrating fish move to the surface at night, while non-migrating fish remain at depth.

What is the typical coloration of mesopelagic fish?

They are often red or orange due to light penetration, which helps them avoid predation.

What is the significance of tubular eyes in some deep-sea fish?

They provide lateral vision and are adapted for low light conditions.

What are the dominant organisms below 2000 m in the ocean?

Echinoderms such as sea anemones, sea cucumbers, and sea stars.

What is the primary reason for the low biomass in deep sea environments?

There is little food available for organisms at these depths.

What adaptations do bathypelagic fish have for capturing prey?

Large jaws with hinges that allow them to engulf large prey.

What is the role of bioluminescent slime in deep-sea organisms?

It can be used for distraction of predators or as a lure for prey.

What adaptations do mesopelagic fish have for protection?

Many have spines and photophores to break up their silhouette.

What is the 'green bomber' in the deep sea?

A species of deep-sea polychaete that releases glowing structures to distract predators.

What is the significance of the species accumulation curve in deep-sea studies?

It shows the diversity and distribution of species in deep-sea environments.

What is the depth range of the abyssal zone?

4000-11,500 m deep

What percentage of the sea bed does the abyss represent?

76% of the sea bed

What are the environmental conditions of deep sea habitats?

No light, high pressure, cold temperatures, slow water movement

What is the primary feeding strategy of abyssal organisms?

Deposit feeding on organic matter in the sediment

What adaptations do abyssal organisms have for low energy environments?

Slow growth rates, late maturation, few eggs, low metabolic rates

What is the dominant type of organism below 4000 m?

Porifera (sponges), sea pens, echinoderms like starfish and sea cucumbers

What is the role of bioluminescence in deep sea organisms?

Used for counterillumination, attracting prey, or communication

What are hydrothermal vents?

Undersea hot springs associated with mid-ocean ridges

What is the primary energy source for organisms around hydrothermal vents?

Hydrogen sulfide, through chemosynthesis

What are the typical conditions found at hydrothermal vents?

No sunlight, high temperatures (up to 390°C), anoxic and acidic water

What is a characteristic feature of vent communities?

High growth rates and diverse species including crabs, fish, and polychaete worms

What is the significance of the coelomate polychaete worm Riftia pachyptila?

It has no mouth or gut and relies on symbiotic bacteria for energy from hydrogen sulfide

What are cold seeps?

Areas where methane and water form solid hydrates, supporting unique ecosystems

What is the Gas Hydrate Stability Zone?

The region where conditions are favorable for methane hydrates to form

What is a unique geological feature associated with asphalt seeps?

Heavy petroleum seeps from the ocean floor and hardens

What are brine pools?

Highly saline, toxic underwater lakes that do not mix with seawater

How do deep sea fauna adapt to their environment?

Uniform grey color, long slender legs, and low densities

What is the primary composition of vent bacteria?

They oxidize hydrogen sulfide to produce energy and organic matter

What adaptations do abyssal organisms have for low mobility?

Fluid-filled flexible bodies and low fecundity

What is the significance of the term 'herd' in relation to sea pigs?

A group of sea pigs is called a 'herd'

What are the main problems for animal life in hydrothermal vents?

High and variable temperature, variable oxygen levels, toxic hydrogen sulfide

What is the role of chemosynthetic bacteria in vent communities?

They provide particulate organic matter for heterotrophic animals

What is the coloration of deep sea benthic animals?

Typically dark brown or black

What is the typical size range of abyssopelagic animals?

Wide size range, from tiny to huge

What is the significance of the term 'counterillumination' in deep sea organisms?

A method used by some organisms to avoid predation by blending with light from above

What adaptations do abyssal organisms have for energy conservation?

High water content and low protein content

What is the mesopelagic zone also known as?

The twilight zone