Arctic Sea Ice, Shipping, and Dispersal

 

The National Snow and Ice Data Center reports that the Arctic sea ice extent recently reached its third lowest for the month of September since we’ve had satellite data.  The minimum extent occurred on September 19th, with 4.6 million square kilometers of ice.  This melt season has since ended; the 5-day average ice extent was recorded at 5.44 million square kilometers on October 1st.

On September 20th, the U.S National Ice Center identified the opening of the Northwest Passage as  satellite images indicated minute levels of multi-year ice present there.  The first commercial ship, the MV Camilla Desgagnés, successfully navigated through the Passage in 2008, potentially leading the way in utilizing this new route for trans-ocean shipping.  However, the opening of Arctic sea ice could bring more than just cargo.  The Arctic has served as a major biogeogaphic barrier since the mid-Pliocene (~3 million years ago).  It has recently been pointed out that with temperature shifts and decreased ice, marine organisms are likely to use the Arctic as a throughway between the Pacific and Atlantic oceans, with unknown ecological effects1.  This may be already occurring to some extent:  a Pacific diatom was observed in 1999 in the Labrador/Irminger seas, betwixt Canada and Greenland.  This particular species was known to have last lived in the north Atlantic more than 800,000 years ago, according to sediment records2.  Shipping is expected to assist this trans-Arctic dispersal of species.  This opening of the Arctic has also spurred claims to the seafloor among Russia, Denmark, Norway, Canada, and the US in order to be able to capitalize on oil and gas reserves likely present there.

Images:  1) National Snow and Ice Data Center, 2) Bill Rankin, Radical Cartography (cc)

1. Sutherland, W., Clout, M., Côté, I., Daszak, P., Depledge, M., Fellman, L., Fleishman, E., Garthwaite, R., Gibbons, D., & De Lurio, J. (2010). A horizon scan of global conservation issues for 2010. Trends in Ecology & Evolution 25 2. Reid PC (2008) Trans-Arctic invasion in modern times. Science 322

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