Peril at the Poles by yurtgc548

VIEWS: 8 PAGES: 33

									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
    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!
           The Southern Ocean
 Semi-frozen ice in combo with salt water
  edge promotes remarkable growth of
  microscopic plankton = base of ecosystem

 Thrive under ice (only)        I RULE YOU
 Food source for Krill              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!

								
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