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The Effects of Global Warming on Marine Ecosystems at the Poles. Peril 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. - PowerPoint PPT Presentation
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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!