Transcript Polar Ecology

Polar Ecology
Toxic
Events
Bhopal,
India
Chernobyl, USSR
Minamata, Japan
“Sea ice is a key component in
structuring polar environments.
Beside its important role as a
platform for marine mammals and
birds, it serves as a habitat for a
unique highly specialized community
of bacteria, algae, protozoa and
metazoa, which contribute to the
biogeochemical cycles of the Arctic
and Antarctic seas.’’
Arctic Ocean bloom
Southern Ocean bloom
2050
Tuvalu will disappear
Will sea level rise from Arctic
melts?
Warming water and melting land ice : mean sea level up 4.5 cm from1993 to 2008
Not uniform
ocean heat storage
Light blue constant
Yellow to white most rapid rise
Slow down in the sub-polar gyre
Thermohaline circulation weakening?
Major Extinctions
Antarctic vs Arctic Ocean
•
•
•
•
•
•
•
•
•
•
•
•
•
50 to 70 degrees S
35-38 million sq km
Narrow shelf, few islands
Shelf 400-600 m
Open to 3 oceans
Circumpolar current
Vertical mixing high
Nutrient high continuously
High primary productivity
Little to no freshwater input
Salinity 34 ppt
High seasonal ice pack
Low benthos disturbance
•
•
•
•
•
•
•
•
•
•
•
•
•
70 to 80 degrees N
14.6 million sq km
Broad shelf, archipelagos
Shelf 100-500 m
At Fram & Bering Straits
Transpolar
Little vertical mixing
Seasonally depleted
Moderate primary productivity
Extensive fluvial input
Salinity 31 ppt
Ice pack seasonally low
Extensive bottom disturbance
Convergent evolution of antifreeze glycoproteins in Antarctic
notothenioid fish and Arctic cod
(repetitive sequenceygene duplicationysequence convergenceytrypsinogen)
LIANGBIAO CHEN, ARTHUR L. DEVRIES, AND CHI-HING C. CHENG*
FIG. 1. Polyacrylamide gel of fluorescently labeled
AFGPs from Antarctic notothenioid Dissostichus
mawsoni (Dm) and Arctic cod Boreogadus saida
(Bs) and the amino acid compositions of the three
size groups of Arctic cod AFGPs. The two polar
fishes show comparable size heterogeneity,
especially AFGP 6-8
Antitropical Distribution:
Carl Hubbs (1952)
Number of fish species between
Antarctic and Arctic
•
•
•
•
•
•
•
•
•
Chondrichthyes
Salmoniformes
Myctophiformes
Gadiformes
Cottidae
Liparidae
Zoarcoidei
Nototheniodei
Pleuronectiformess
•
•
•
•
•
•
•
•
•
11 vs 26
0 vs 32
35 vs 7
21 vs 44
0 vs 44
31 vs 17
22 vs 67
95 vs 0
4 vs 28
Marine Mammals
• Mammals that use the sea in their natural
history
• Has evolved 5-8 times
• Extant groups
– Ceataceans
– Sirineans
– Pinnipeds
– Sea Otter : Mustelidae, Enhydra lutris
– Polar Bear : Ursidae, Ursus maritimus
Break
• 4 types of people
Living at sea
•
•
•
•
•
•
•
Can’t respire in water
Heat loss greater
Locomotion in denser medium
Hearing: asymmetrical skull
Low visibility
Time spent in water varies with species
Lack of freshwater
Adaptations
•
•
•
•
•
Polar bears: not adapted for diving
Sea otters: not accomplished divers
Pinnipeds: great diving capabilities
Sirenians: totally aquatics, decent diver
Cetaceans: Most derived
Sirenians
Character transformation
Types of Characters
•
•
•
•
Behavioral
Physiological
Morphological
Molecular
Suborder Pinnipedia
• Otariidae (eared seals, 16 spp)
– Shallow divers
• Odobenidae (walrus, 1 spp)
• Phocidae (true seals, 19 spp)
Order Cetacea
60 to ~200,000 kg
• Baleen whales (mysticetes, 13 spp)
– Balaenopteridae: 8 spp of rorqual whales
– Balaenidae: 3 spp of right whale & bowhead
– Neobalaenidae: 1 spp pygmy right whale
– Eschrichtiidae: 1 spp gray whale
• Toothed whales (odontocetes, 70 spp)
Toothed whales (odontocetes)
•
•
•
•
•
10 families, 70 spp
Physeteridae: sperm whale
Monodontidae: beluga & narwhal
Delphinidae: 35 spp dolphins, killer whale
Phocoenidae: 6 spp porpoises
Dolphin vs Porpoise