I've been with working with Ari Friedlaender and David Lavigne (see collaborators page) on a project examining sea ice dynamics in the North Atlantic and their effects on breeding pagophilic seals. Previously, we established that the mode of the North Atlantic Oscillation contributes strongly to the amount of sea ice 
off eastern Canada (study available here). This is an important breeding site for harp and hooded seals, and these animals depending on ice as a platform to give birth to and nurse their pups. We've recently expanded this study to look at the other breeding sites for harp seals - the West Ice and the White Sea. While the results are certainly preliminary (and soon to be presented at the CLIOTOP 2007 meeting), at right is a sneak-peek at one of the results. As we found previously, sea ice tends to be in phase with the NAO signal - meaning that when the NAO is positive, there is greater and more persistent sea ice. Interestingly, it appears that the White Sea is actually out of phase with the NAO, exhibiting lower ice concentrations when the NAO is positive. Cool stuff, and more to come.
“The Exploration of the Pacific”
Marine Mammal Science and ConservationSea Ice and the NAO
1 Comment
“The Exploration of the Pacific” » Harp seals in the Northwestern Atlantic: Did cumulative effects of harvests and climate variability lead to rapid depletion? wrote @ December 5th, 2007 at 7:43 am
[…] Considering that sea ice concentration in eastern Canada is "in phase" with the NAO (see below), it stands to reason that this period exhibited poor ice conditions (we know that 1969 is one of the worst on record), and therefore increased seal mortality. Interestingly, the harp seal population plummeted during this negative NAO period, dropping by at least 55% during 1950 to 1970. During this time seal catches were relatively high…and it seems that the combined effects of reduced sea ice and large harvests may best explain the dramatic drop in seal numbers. […]
Sorry, the comment form is closed at this time.