Polar Ecology
“Sea ice is a key component in structuring polar environments “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.’’
Our ocean: connected at Depths
Regions 90N to 70N 70N to 50N 50N to 30N 30N to 10N 10N to 10S 10S to 30S 30S to 50s 50S to 70N
Ozone Hole : 220 Dobson unit
Primary production likely be affected – open discussion
Arctic 79 vs 07
2050
Will sea level rise from Arctic melts?
Warming water and melting land ice : mean sea level up 4 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
Great Auk Stellar’s sea cow
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