Polar Ecology

Polar Ecology

Bhopal, India

Minamata, Japan

Chernobyl, USSR

Toxic Events

“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?

Not uniformocean heat storageLight blue constant Yellow to white most rapid riseSlow down in the sub-polar gyreThermohaline circulation weakening?Major Extinctions

Warming water and melting land ice : mean sea level up 4.5 cm from1993 to 2008

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

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

Convergent evolution of antifreeze glycoproteins in Antarcticnotothenioid fish and Arctic cod(repetitive sequenceygene duplicationysequence convergenceytrypsinogen)LIANGBIAO CHEN, ARTHUR L. DEVRIES, AND CHI-HING C. CHENG*

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 Cetacea60 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