The Effects of Global Warming on Marine Ecosystems at the Poles

By: Amber Mueller

Global Warming:

the increase in the average temperature of the Earth’s near-surface air and oceans due to the increase of greenhouse gasses in the atmosphere, and its projected continuation

The Poles:

Includes:the Arctic – Arctic Ocean, parts of Canada, Greenland, Russia, the U.S(Alaska), Iceland, Norway, Sweden, and Finland

And the Antarctic – Surrounded by the Southern Sea Protected by the Antarctic Treaty

The Cryosphere:

Portions of the Earth’s surface where water is in solid form

Importance? Ice reflects sunlight, keeping temps

BUT when the ice melts, water absorbs 4 times as much light, heating the ice in the water and thus heating the poles and destroying the Cyosphere

Water, Water, EVERYWHERE! Semi-frozen ice in combo with salt

water edge promotes remarkable growth of microscopic plankton = base of ecosystem

Thrive under ice (only) Food source for Krill

The Southern Ocean

I RULE YOU ALL!

The Great Southern Ocean

Krill cash cow ($$$) 60-70% of southern hemisphere krill pop

Before 1939- stable krill pop Since 1976- nearly 40% decrease per

decade

Chain of Life…

Increase of Jelly-like Salps modest dietary

needs

devoid of nutrients

not a food source to any marine birds or mammals

Say Goodbye..

“Penguins, albatrosses, seals and whales are prone to krill shortages”- Atkinson

Ice and Krill

sea ice volume was stable between 1840 and 1950

began decreasing after that -20%

krill pop numbers coincided climate change is a profound threat to

the most productive ocean in the world.

Impact?

Emperor penguin population is half of what it was thirty years ago

Adelie penguins have declined 70%.

Impact… southern right

whales need to feed on winter krill in order to have energy to swim to mating grounds

humpback whales, seals, and penguins will be on the verge of extinction

A Sea of Jelly Salps!!!

The Arctic: Home of about 4 million better

studied

Winters in Alaska are 4-5 degrees warmer than they were 30 years ago

Visible Changes

Atlantic hair grass is growing at higher altitudes

spruce bark beetle killed 40 million trees in southern Alaska

Worst insect destruction in NA history

Forest Encroachment Overall decrease in population of

Birds and Mammals

The Spruce Beetle:

Population is usually controlled by cold winters

Mild temperatures allow the species to survive and destroy

More Bugs…

Spruce budworms are also a threat

female budworms lay 50% more eggs at 77 degrees than at 59 degrees.

The Arctic Climate Impact

2004- the Arctic Climate Impact Assessment

As the forest encroaches northward to the Arctic Sea the tundra will be destroyed

Predicted that at least 50% of suitable habitat will be lost by the end of the century

Bye Bye Birdie

Several hundred million birds migrate to the treeless tundra to breed

When the tundra is gone great flocks will be destroyed

The Collard Lemming Represent winter

endurance and resilience superbly adapted to life

in cryosphere Only rodents whose coat

turns white in winter and claws turn to two-pronged shovels for snow tunneling

habitat the tundra they will go extinct by end of century

Impact on Caribou: increase in rain causes lichens (their

food source) to freeze over changed snowfall patterns kill calves

as they try to migrate

numbers have dropped from plentiful 26,000 in 1961 to 1,000 in 1997

The Ringed Seal most abundant mammal in far north

yet if the temp isn’t cold enough for snow to fall they cant make their dens cant breed

many have left for Siberia leaving the polar bears to starve

More Seals…

Harp seals are similar

the number of ice free years often exceeds the female reproductive life

Gulf of St. Lawrence population is almost extinct with no hope of recovery.

Ringed, ribbon, bearded seals, and walrus all live under the same threat

The Great Nanuk

can survive at the harshest of temperatures

Have been spotted within 100 miles from the true North pole!

Only thing that stops them is lack of food

Polar Bears: long term study of 1,200 individuals average of 15% skinnier than a

decade ago feeding season has become too short potential food has migrated Each year starving females give birth

to fewer cubs

Polar Bear Breeding Twenty years ago a mother could support

triplets and about half of all cubs born survived

Now the survival ratio is 1:20

Increasing winter rains collapse dens killing mothers and cubs

More Threats:

Early break up of ice can separate denning and feeding areas b/c most cubs can’t swim far enough

Who Cares? Usually a healthy, well fed polar bear

eats the fat off a seal, leaving the rest to the arctic fox, the raven, Thayer’s and ivory gulls

some parts of the year these animals depend solely on polar bears scraps

Chain, Chain, Chain…

Ivory Gulls have decreased in pop 90% over last 20 years due to habitat disappearance and lack of food

What does all of this Mean?The Arctic Realm will be replaced

by polar deserts and encroaching forests

more forests = more heat they will trap (ice reflects light, trees absorb light ) which will heat the planet ever more swiftly

Going, Going, Gone

The Cryosphere will vanish and with it all the animals of the Arctic and Antarctic will become extinct.

UNLESS WE DO

SOMETHING ABOUT

IT!