Polar SeasPolar Seas• Polynyas are the active,

open water areas surrounded by ice, where life congregates.

• Because the water is cold, oxygen is rich.

• Summer Season– Increased light availability– Phytotplankton blooms– Upwelling is frequent due

to high winds over low terrain

• Dominant phytoplankton - diatoms

• Dominant zooplankton - krill

• Short food chains yield high productivity and high population density.

• The number of species is low as food chains do not allow for diverse niches.

North Pole• Winter months (Dec-Jan) of 24

hrs of darkness• Summer months (June-July) of

24 hrs of daylight• Ocean ecosystem• Tall jagged icebergs• Average temperatures

– Winter: -30oF– Summer: 32oF– Siberian record: -92oF

• Pinnipeds (seals, sea lions, walrus)

• Polar bears• No penguins

South Pole• Winter months (June-July) of

24 hrs of darkness• Summer months (Dec-Jan) of

24 hrs of daylight• Land ecosystem• Smooth, flat ice cap• Average temperatures

– Winter: -78oF– Summer: -20oF– Vostok record: -128oF

• Pinnipeds• Penguins• No walrus• No bears

History of Polar ExplorationHistory of Polar ExplorationNorth Pole - Arctic Ocean • 1909 - Robert Peary

reached the pole (US)• 1926 - Admiral Byrd first

to fly over North Pole• 1929 - Amundsen died in

air ship rescue• 1958 - US Capt. Anderson

sailed under the Arctic Ocean from Alaska to Greenland

South Pole - Antarctica Continent• 12/13/1911 - Roald Amundsen of

Norway reached the South Pole• 1/18/1912 - Robert Scott reached

the South Pole• 1915 - Shackleton’s ship is crushed• 1939 - Ross Shelf first Navy Base• 1955 - Admiral Byrd - Operation

Deep Freeze established 8 stations for research during the International Geophysical Year

• 1959 - Antarctica Treaty signed• 1962 - First nuclear power plant

built at the South Pole

PinnipedsPinnipeds

Phylum: ChordataClass: MammaliaOrder: CarnivoraSuborder: Pinnipedia

(means fin footed)Examples: seals, sea lions,

walrus (33 species)

General Characteristics:- excellent swimmers- Thick layers of blubber to

protect from cold- Make a barking sound- Nostrils positioned on the

snout and can close for diving.

- The largest pinniped is the Elephant Seal at 8,000 pounds.

Pinnipeds are in 3 groups:1. Otariidae

- eared seals- Sea lions & fur seals- Can rotate both pectoral

and pelvic fins to walk on land

- Very social- Males have huge harems

of up to 100 females - they fight to control

2. Phocidae- true seals- No visible ear flap- Front legs do not rotate and

will not support their weight

- Easy prey for polar bears, killer prey because they must drag their back fins.

- Excellent swimmers

3. Odobenidae- walruses are found only

in the North Polar regions

- Use their tusks to hoist them onto ice & dig for clams

- Can dive to 300 ft.- Nearly became extinct

because of human hunting for their ivory tusks

Pinniped diet:- Krill- Crustaceans- Mollusks- Fish- Squids- Leopard seals eat penguins

Pinnedpeds haul-out to:- Rest- Sun- Molt- Breed- raise young.

• Most Pinnipeds (except the walrus) are covered with dense waterproof fur that was attractive to man.

• Since the Marine Mammals Protection Act of 1972, hunting is illegal. As a result, the shark has also experienced an increase in population because its food source is readily available.

OttersOtters• Smallest marine mammal• Not a pinniped because it

has 4 functioning limbs• High metabolic rate• Quickly die of

hypothermia when their fur is damaged

• Have no blubber

• 90% of the worlds’ otter population lived in the coastal waters from Prince William Sound to the Aleutian Islands

Exxon Tanker, Valdez Oil Spill

• More than 1500 otters killled

• Only a few hundred otters were saved.

• Dozens of orphaned otters were sent to zoos and aquaria

• Otter pups can’t swim so they float or rest on the mother’s stomach

• Males & females only socialize for a few days a year to mate

• Otters use tools such as rocks to break open abalone.

• Fisherman sometimes shoot otters because their appetites make them a competitor for abalone and fish.

• Declining abalone population is probably more often the result of over-fishing and the destruction of habitat.

• Otters help control the sea urchin population, who are destroying the kelp beds where the abalone live.

CurrentsCurrents are important

because they:- moderate climates- Mix nutrients &

oxygen- Transport larvae &

nekton

Currents are caused by:1. Spin of the earth on

its axis and the Coriolis effect

2. Ekman transport results in movement at a 90o angle to the wind

3. Warm air from equator flows toward the poles drives air circulation, makes wind

4. Continents deflect east-west water movement, but no air.

Gyre Currents• The characteristic

patterns of surface water currents.

• Northern hemisphere - the gyre is (right) clockwise

• Southern Hemisphere - the gyre is (left) counter-clockwise

Western Boundary Currents1. Located on the western

side of oceans.2. Currents bring warm

water from the equator3. High salinity4. Low oxygen content5. Nutrient poor,

infrequent upwelling6. Lower biomass

Eastern Boundary Currents• Located on the eastern

side of the ocean• Currents bring cold

water from the poles• Low salinity• High oxygen content• Nutrient rich due to

upwelling• High biomass

• Thermohaline currents are found on the ocean floor - “thermo”= temperature and “haline”= salinity/density

• Water slows down below the pycnocline (area defining water masses of different densities) to 1-2 meters/day

PenguinsPenguinsThere are 18 species of penguins,

who all belong to the Order Sphenisciformes, Class Aves.

Primary Habitat:- antarctica and surrounding

islands- Warm coastal areas of W.

South America- Southern Africa- Australia- New Zealand- Galapagos Islands

• The Emperor Penguin is the largest at 4 ft. and 90 pounds.

• The Blue Penguin is the smallest at 16 inches and 2 pounds

• Some Penguins have yellow crest feathers like the Macaroni, rockhopper, Royal and Fjordland.

• The Adelie is the common cartoon character with its black and white “tuxedo”.

• Penguins mate for life and can find their mate on crowded beaches among thousands of birds by its voice or call.

• Most penguins build nests of rocks, sticks, feathers, moss - whatever is available to lay their eggs.

• May migrate thousands of miles to spend summers in an ancestral rookery on Antarctica’s shores

• The King & Emperor penguins carry their eggs on their feet.

• In some species, the male cares for the egg all winter, tucked in a brood pouch kept 80o warmer than the temperatures outside.

• Penguins lay 1-2 eggs and a few species may raise two chicks if food supply is good. Others only care for the second “B” egg which is larger.

• Both parents help feed the chicks by regurgitation.

• On warms the egg or chick while the other feeds.

• Some may go over 3 months between feeding turns.

• If the hunting mate fails to return with food, the remaining parent will be forced by hunger to abandon the chick

• Penguins eat:- Krill- Fish- Squid

• Penguins may be eaten by: - Seals- Birds- Killer whales

Body Structure• Bones are not hollow -

makes swimming & diving easier.

• The Emperor can dive to 900 ft.

• Penguins CAN’T fly• Short wings are used like

paddles in the water.• Dense feathers & thick

fat keep them warm• Skin contains 70

feathers per square inch

• They molt their feathers• Do not enter the water when

molting.• High metabolism - overheating is

a problem.• Walk with their wings out to the

side to cool off.

• Streamlined bodies aid in fast swimming (15 mph)

• They travel long distances by “porpoising” or swimming like a porpoise with jumps and plunges.

• Allows them to breathe without slowing down.

Auroras• Aurora Borealis

(Northern Lights)• Aurora Australis

(Southern Lights)• High energy particles

escaping from holes in the sun’s corona create solar wind. When the particles collide with the Earth’s Magnetosphere, the energy of the particles is turned into light

• Northern Hemisphere – can be seen best above the Hudson Bay during the equinox in March & October

• Auroras often last 20 minutes and have no regular pattern of occurrence.

• To see an aurora, the sky should be cloudless and relatively dark from ground lights.

El Nino & La Nina• Normally trade winds blow

warm surface water toward the Western Pacific.

• Warm water piles up in the Western Pacific about 1.5 ft. higher than the average ocean surface due to wind and Ekman transport.

• This causes the thermocline to rise near the surface in the Eastern Pacific.

• Cold, nutrient-rich water upwells from the thermocline to the surface waters off the coast of Peru - good for fishing.

• This image shows normal sea surface temperature in the Equatorial Pacific

• Notice the warm water in a pool in the Western Pacific Ocean

• El Nino describes unusual oceanic and atmospheric conditions.

• El Nino’s weaker trade winds blow warm water eastward, across the equatorial region of the Pacific.

• This depresses the thermocline across the Pacific and stop upwelling.

• Because warm water evaporates faster, the air fills with more water vapor and produces more rain.

• El Nino occurs primarily in the tropical Pacific Ocean but it affects global weather.

• La Nina - When too much westerly wind blows surface water near the Americas, it has an effect on the weather that is often opposite to El Nino

http://www.signalsofspring.net/aces/elnino_animation.html

El Nino• Warmer ocean

temperatures• Occurs every 3-7 years• Wetter than normal

summers• Weak trade winds• Decreases forming in

N. Atlantic

La Nina• Colder ocean

temperatures• Frequency unknown• Drier than normal

summers• Strong trade winds