polar ocean ecosystem Flashcards
location
arctic ocean & southern ocean
arctic & antartic characteristics
Cold ! Dry and windy Sea ice Oxygen-rich & nutrient-rich waters Periods of continuous darkness (winter) and of continuous daylight (summer) => Very productive summers
arctic ocean characteristics
Surrounded by land Arctic circle: 66oN -2 to 5oC 33 to 35 ppt Greatest influx: Norwegian current Greatest efflux: East Greenland current
southern ocean characteristics
Surrounded by oceans
Antarctic circle: 66oS
Antarctic Circumpolar current
Isolated by Antarctic Convergence:
-2 to 2oC
34 to 36 ppt
antartica characteristics
Cold (Coldest air temperature ever recorded on Earth was −89.2 °C at Vostok, Antarctica on 21 July 1983) Windy Dry (desert–like) 50 mm snow/yr (interior) 200 mm (coasts) mountainous
why is antartica colder than the artic
Elevation: much of Antarctica is more than 3 km
above sea level and temperature decreases with
elevation
Water covers the north, land covers the south: the
ocean’s relative warmth is transferred through the
icepack and prevents temperatures in the Arctic
regions from reaching the extremes typical of the
land surface of Antarctica
what are the physical adaptations to life at the poles?
Physical adaptations: blubber (or fat), thick
coats, small extremities, big bodies
what are the behavioural adaptations?
huddling, shelter
in dens, curl up & cover muzzle
what are the physiological adaptations?
slow
metabolism, lack of red blood cells,
antifreeze in fish blood, countercurrent
heat exchangers
beluga adaptations
Blubber – layer of vascularized fat under the skin of
cetaceans, pinnipeds & sirenians
No dorsal fin for ease of movement under the ice
polar bear adaptations
Very dense fur – undercoat plus guard hairs of varying length
Each hair is transparent (pigment-free) and hollow which reflects visible light (like snow & ice)
Black skin to absorb light energy
human impacts on polar sea
Decreasing sea ice extent
Melting ice caps & permafrost (positive feedback
through albedo effect and release of CO2 and
Warming water is less dense
Melting of ice caps also decreases density of polar
seawater
Decreased sinking / thermohaline circulation
Species distribution: pole-ward shift of some species; habitat
loss
Ocean acidification
Diffusion of anthropogenic CO2 into seawater causes 🡻 pH
Greatest impact in Bering Sea due to cold water absorbing more
CO2
Marine debris / pollution / oil spills
Overfishing / whaling
Tourism & research (garbage / sewage / disturbing
species)
human impacts on the arctic
~ 4 million humans live in the Arctic
Fishing, sealing, whaling
Pollution –PCB’s, mercury, persistent organic pollutants
Oil and gas exploration & extraction / pipelines / mining /military activities
human impact on the antarctic
Humans include scientists and tourists (no indigenous population)
Overfishing / whaling
Albatross bycatch from longlining
No mining / no military activity
what countries own the north pole?
russia canada norway iceland denmark US
What are the governmental implications and treaties regarding the Arctic?
Arctic Council (1996) – intergovernmental forum promoting cooperation, coordination and interaction among the Arctic States, Arctic indigenous communities and other Arctic inhabitants on common Arctic issues, in particular on issues of sustainable development and environmental protection in the Arctic.
8 countries: USA, Canada, Russia, Norway, Finland, Denmark (representing Greenland and Faroe Islands), Iceland, Sweden
who owns antartica?
UK, Argentina, Norway, Chile, New Zealand, Australia, France
what’s the territory of antartica that’s unclaimed?
Marie Byrd Land
What are the governmental implications and treaties regarding Antartica
Antarctic Treaty (1959) – 12 original signatories
53 nations party to the treaty
14 articles related to peace (no military activity), research,
no nuclear activity, no mining
What’s CCAMLR?
CCAMLR - Commission for the
Conservation of Antarctic Marine
Living Resources (1982)
Started to address concerns about
overharvesting of krill
24 member states + EU
11 acceding states
keystone species
krill
enumerate few of the conservation efforts
ASOC – Antarctic and Southern Ocean Coalition (1978)
Biggest success: mining ban
Inuit Circumpolar Council multinational NGO (1977)
- Canada, Russia, Greenland, USA – Alaska
conservation efforts (NGOs)
Greenpeace, Sea Shepherd Society, Sierra Club, Nature
Conservancy, WWF
Research
Education
Activism
arctic fox adaptations
Long guard hairs and very dense undercoat
Countercurrent heat exchange in legs to maintain core body temperature while walking on cold substrate
Lots of body fat
Low surface area to volume ratio to minimize heat loss – rounded body with short legs, ears & muzzle
emperor penguin adaptations
Large bodies (30 kg, 1.2 m tall)
Feathers help maintain body temp.
Subcutaneous fat
Huddling to conserve heat
Slow metabolism
High oxygen-affinity hemoglobin
Solid bones & bradycardia (diving)
what’s bradycardia
slower than normal heart rate to maintain homeostasis.
why are some invertebrates gigantic?
Cold water, low metabolic rates, lots of oxygen leads to slow growth and gigantism
give two examples of invertebrates
krill & Lion’s mane jelly
what’s the average ice thickness in Arctic waters?
2-3 m
what’s the average ice thickness in Antarctica
1-2 m
ice sheet
a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km² (thickness 216-4776 m)
ice cap
ice cap is a mass of ice that covers less than 50,000 km² of land area.
ice shelf
permanent floating sheets of ice that connect to a landmass.
by how much can Antarctica raise the sea level
by 62 m
ice berg
a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water.
bergy bit
a medium to large fragment of ice
growler
small iceberg
albedo
non-dimensional, unitless quantity that indicates how well a surface reflects solar energy
positive feedback
a process wherein some initial change in the climate causes some secondary change that in turn increases the effects of the initial change, essentially magnifying the initial effect
describe how the ice albedo is an example of positive feedback
with warming, ice melts this leads to ocean exposure which means less albedo => increase in sunlight => warming (ice is more reflective)
krill adaptations
the ability to shrink their bodies and undergo long periods of starvation.
lion’s mane jelly adaptations
tentacles are equipped with nematocysts containing poison that stun prey when they are enveloped
adapted to cold waters and human impact
polar bears adaptations
Very dense fur – undercoat plus guard
hairs of varying length
Each hair is transparent (pigment-free)
and hollow which reflects visible light
(like snow & ice)
Black skin to absorb light energy
Antarctic convergence
where the cold Antarctic waters meet the warmer waters of the subantarctic, creating a zone of upwelling nutrients. These nurture high levels of phytoplankton with associated copepods and krill, and resultant foodchains supporting fish, whales, seals, penguins, albatrosses
Countercurrent heat exchange
Blood flowing from the body core to the periphery (like the legs & feet) carries heat that can be readily lost through the skin.
