While researching the population status of Foxe Basin polar bears I came across an issue that seems to have garnered relatively little attention outside the polar bear community – Inuit objections to the handling of polar bears during mark-recapture surveys and the effect of this on polar bear research in Canada.
Foxe Basin is a large polar bear subpopulation region that encompasses the northern portion Hudson Bay into the area west of Baffin Island, see map below (courtesy IUCN Polar Bear Specialist Group).
Mark-recapture research methods routinely used by polar bear biologists became especially contentious in Foxe Basin during a population study initiated in 2007/2008, with Inuit residents voicing objections and biologists defending its practice. The following year, the mark-recapture effort was halted and an aerial survey took its place.
The aerial survey has been completed and a report on it was released in 2012 (Stapleton et al. 2012; see previous post for results) but we’ve heard very little about what happened to that mark-recapture study and why the Government of Nunavut pulled the plug on it. I plan to change that with the next couple of posts.
I’m not claiming to understand the nuances of the story because I’m only going by available documents. However, I think it’s important to shine some light on this issue since it has clearly changed the shape of polar bear research in Canada.
Posted in Life History, Population
Tagged aerial survey, Atkinson, Canada, Derocher, field work, Foxe Basin, Inuit, mark-recapture, non-invasive research, Nunavut, objections to mark-recapture, Peacock, polar bear handling, polar bear research, research methods, Stapleton, tainted meat, tranquilizer drugs, Zoletil
Figure 1. Polar bear subpopulation regions defined by the Polar Bear Specialist Group, Foxe Basin marked.
Foxe Basin is a large subpopulation region (Fig. 1), with a total area of 1.18 million square km (Vongraven and Peacock 2011). It comprises Northern Hudson Bay and western Hudson Strait, and the area between western Baffin Island and eastern Melville Peninsula, with a large island (Southampton Island) in the middle (Figs. 2 and 3).
Figure 1. Foxe Basin polar bears subpopulation region, courtesy IUCN PBSG
Posted in Life History, Population
Tagged aerial survey, body condition, fatty acid analysis, Foxe Basin, mark-recapture, Mitch Taylor, Nunavut, Obbard, Peacock, polar bear diet, Polar Bear Specialist Group, population status, Stapleton, starving polar bears, Thiemann
From this story in today’s Alaska Dispatch (via CBC NewsEye on the Arctic), November 11, 2013, which adds a few more details regarding the progress of ongoing population surveys and the next PBSG meeting:
“The Nunavut government has wrapped up three years of fieldwork on Baffin Bay polar bears, and is preparing to release a new population estimate sometime next year….
So far, I’ve not discussed the Barents Sea subpopulation in very much detail, except in comparison to other groups. For example, the Barents is considered to be the same type of sea ice “ecoregion” as the Chukchi Sea and the Southern Beaufort (discussed here). Previous studies on the Barents Sea polar bear population (Derocher 2005) indicate it may have recovered from extreme levels of overhunting (discussed here) and had stabilized, or was increasing very slowly, as early as 2002 (discussed here) — similar to what has happened in Davis Strait (discussed here).
Figure 1. Polar bear subpopulations, with the Barents Sea region highlighted; map courtesy the IUCN Polar Bear Specialist Group (PBSG), extra labels added.
The most recent Barents Sea population estimate was done in 2004 (2,650; range ~1900-3600), based on an aerial survey (Aars et al. 2009). Aerial surveys are the only practical method of establishing population counts in regions like this where many bears never set foot on land. The previous estimate for the Barents (1982) was “2,000-5,000” but its accuracy was considered “poor” (discussed here).
The IUCN Polar Bear Specialist Group (PBSG), in their most recent report, lists the Barents Sea population as “data deficient” for status, current trend and estimated risk of decline within 10 years (Obbard et al. 2010:62, Table 1) and the “notes” for this entry say:
“Population estimate is based on a new aerial survey. There was likely an increase in the subpopulation size after 1973 until recently. Current growth trend is unknown.”
This 2004 estimate is now almost a decade old and potentially no longer an accurate representation of what’s happening in the Barents Sea. The most up-to-date information has not yet been published but it is available online. It’s eye-opening to say the least, if only that it appears to be yet another example of a polar bear population that is so far not showing signs of being harmed by sea ice declines, as I’ve discussed before (here).
[Update October 15, 2013: I’ve simplified the text discussion and figure regarding the Aars and Andersen denning study from the original posted]
Posted in Conservation Status, Life History, Population, Sea ice habitat
Tagged aerial survey, Barents Sea, body condition, Derocher, ecoregrions, Environmental Monitoring of Svalbard and Jan Mayen, Jon Aars, litter size, Magnus Andersen, maternity dens, Mauritzen, MOSJ, number of cubs, Olga Pavlova, population size, pregnant females, reproduction, sea ice, Sebastian Gerland, Svalbard