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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