Bearded and ringed seals join the polar bear as “threatened” by a computer-modeled future

As I pointed out in Featured Quote #22 (posted on Dec. 23, 2012), bearded and ringed seals have recently joined the polar bear on the American ESA’s list of animals that are “threatened” by computer-modeled predictions of Arctic sea ice declines projected 50-100 years into the future.

NOAA photos of bearded seal (top) and ringed seal (bottom)

NOAA photos of bearded seal (top) and ringed seal (bottom). The bearded seal is one of the largest Arctic ice seal while the ringed seal is the smallest. Both are eaten by polar bears, although ringed seals are consumed most often.

The decision by NOAA (National Oceanographic and Atmospheric Administration) affects the Arctic subspecies of ringed seal (Phoca hispida hispida) as well as the Okhotsk subspecies (Phoca hispida ochotensis) (in addition to several others) and thus includes all ringed seals off Alaska’s coast in the Beaufort, Chukchi and Bering Seas. The decision also affects two particular subpopulations of bearded seal (Erignatha barbatus): the “Beringia” [Bering Sea/Chukchi] subpopulation (about half of which reside in Alaskan waters), and the subpopulation that lives in the Sea of Okhotsk. (Alaska Fisheries (NOAA) Final Decision).

[Note that ringed seals have been divided into subspecies but bearded seals have not, primarily because there has been so little research on bearded seals - indeed, the Okhotsk Sea ringed seal "subspecies" designation is based on assumptions, not evidence (Kelly et al. 2010:36). There is also a taxonomic disagreement regarding the ringed seal: NOAA uses Phoca hispida as the species name, while the IUCN uses Pusa hispida - I mention this only so folks don't get confused if they notice this disparity in the literature, which is based on conflicting genetic studies that I won't get into here.]

Bearded and ringed seals are found throughout the arctic (in other words, they are both “circumpolar” in distribution), but the populations in the Bering/Chukchi Seas and Beaufort Sea (and marginally, the Okhotsk Sea) are the ones that are of particular concern to US management agencies.

According to the latest surveys (some of which are based on incomplete or questionably accurate data), there were more than 278,000 bearded seals in the western Arctic (Bering, Chukchi, Beaufort, Okhotsk and East Siberian Seas) (Cameron et al. 2010) – see Fig. 1 below (which I have borrowed from the article by Zac Unger, in the latest issue of Canadian Geographic magazine, which I mentioned in a previous post here). There are no indications that current populations of bearded seals are declining (Cameron et al. 2010.)

Fig. 1. Map of the Arctic showing polar bear subpopulations and sea ice. Reproduced from Canadian Geographic, December issue, "The truth about polar bears," by Zac Unger. Click to enlarge

Fig. 1. Map of the Arctic showing the distribution of polar bear subpopulations and sea ice extent, which overlap the distribution of bearded seals everywhere except the Okhotsk Sea in the Russian Far East (upper left of the map, not labeled). Reproduced from Canadian Geographic, December issue, “The truth about polar bears,” by Zac Unger.

Ringed seals live in the same areas of the western Arctic as bearded seals, and their global population has been estimated at 3-4 million individuals (Kelly et al. 2010). Ringed seals are the most abundant of all Arctic seals. In the western Arctic (Bering, Chukchi, Beaufort, Okhotsk and East Siberian Seas, see Fig. 2 below), there are estimated to be more than 1,676,000 ringed seals. That’s 1.7 million. There are no indications that current populations of ringed seals are declining (Kelly et al. 2010).

Fig. 2. Map of global ringed seal distribution, from Kelly et al. 2010:61. Note that these authors include the Bering Sea in the "Chukchi Sea" population. Click to enlarge.

Fig. 2. Map of global ringed seal distribution, from Kelly et al. 2010:61. Note that these authors include Bering Sea seals in the “Chukchi” population. Bearded seal distribution is almost identical to this in the western Arctic.
Click to enlarge.

Similar to these two ice seal species, polar bear numbers have so far not seen a documented overall decline, although there have been a few ups and downs within subpopulations – see my previous post on the history of polar bear numbers here and here for a discussion of polar bear distribution. The upper population estimate for polar bears has officially remained at 25,000 since 2001 (Lunn et al. 2002), indicating no overall decline in numbers that can be attributed to changes in sea ice habitat.

However, in contrast to the polar bear, whose international (IUCN) status was established in 2006 in advance of the 2008 ESA pronouncement that it be considered “threatened” - see previous post here – both bearded and ringed seals were assessed in 2008 by the IUCN and classified as Least Concern (Kovacs and Lowry 2008; Kovacs et al. 2008):

Bearded seal, year published 2008, Red List category Least Concern (ver 3.1).Due to its large population, broad distribution, variable feeding habits and no evidence of a decline, the Bearded Seal should be classified as Least Concern.”

Arctic subspecies of ringed seal [primary prey of the polar bear], year published 2008, Red List category Least Concern (ver 3.1).  “P. h. hispida [the Arctic subspecies]- For the global assessment at the species level, the Arctic Ringed Seals’ numerous status and broad distribution leads to the classification of Least Concern for this species.” [my bold]

And according to this news report Mary Kauffman, at SitNews (Ketchikan, Alaska), published the day after Christmas (“Murkowski Lashes Out at “Overbroad, Overreaching” NOAA Seal Decision, State Considers Challenge; Senator Sees Christmas Friday Announcement as Evasive Tactic”), officials for the state of Alaska are fighting mad about this decision:

“I believe that Alaska’s wildlife must be protected, but not by relying on overbroad, overreaching analysis that runs counter to the abundant seal populations we presently see,” said [U.S. Senator Lisa] Murkowski. “There is something misguided about policy that is guaranteed to cause real economic impact on the horizon based on a hundred year hunch. No wonder NOAA decided to release this decision the Friday before Christmas, hoping it won’t register with Alaskans.”

Upon hearing of NOAA’s Dec. 21st decision, Governor Sean Parnell announced the same day that the State of Alaska is evaluating a potential challenge to two decisions by the National Marine Fisheries Service (NMFS) listing the ringed seal and the bearded seal as threatened or endangered species under the Endangered Species Act (ESA).

The ringed seal population currently numbers in the millions and the bearded seal population in the hundreds of thousands. The state contends that no evidence was presented demonstrating either species is experiencing a decline now or will so by mid-century.

“The ESA was not enacted to protect healthy animal populations,” Governor Parnell said. “Despite this fact, the NMFS continues the federal government’s misguided policy to list healthy species based mostly on speculated impacts from future climate change, adding additional regulatory burdens and costs upon the State of Alaska and its communities, and wresting away Alaska’s sovereign interest in managing its own wildlife and resources.”

“The NMFS listed the species as threatened or endangered based primarily on climate models predicting sea ice habitat changes nearly 100 years into the future,” said Doug Vincent-Lang with the Alaska Department of Fish and Game. “The accuracy of such modeling becomes increasingly speculative and unreliable the farther into the future a prediction is made, particularly when such predictions exceed 50 years.”

The State of Alaska, industry groups, Alaska Native communities and others had issued numerous comments decrying the proposal to list the seals as threatened. Environmental activists sought the new listing.” [my bold]

Crystal ball predictions by climate models notwithstanding, the fact of the matter is (as discussed in Featured Quote #20 and in a previous post here) that for seven of the last 10 years, the Bering Sea has had above-average sea ice coverage. Last year (2011) broke the record for sea ice extent in the Bering Sea and so far, this year has well above average extent as well. The most prominent feature of Bering Sea ice conditions is now acknowledged to be wide variability (Brown et al. 2012). And because about half of the total number of western Arctic seals and polar bears that the USA has any legitimate management concern over reside in the Bering Sea, this disconnect of reality vs. sea ice models is critically important.

Recall my previous post about Chukchi/Bering Sea polar bears, which included this quote from US Fish & Wildlife polar bear biologist Eric Regehr:

“In 2009, when the PBSG [Polar Bear Specialist Group] issued its population status reports, it listed the Chukchi Sea population, which Alaska shares with Russia, as being of unknown size, but one thought to be in decline because of anecdotal reports about possible over-harvesting in Russia. But now, newer research yet to be published has scientists reconsidering the status designations of the Chukchi population, Regehr said. It appears the bears in this area are reproducing well and maintaining good body condition.”

And my response to that was: “So, it turns out that what these expert polar bear biologists “believed” to be the case – without any data to back it up – is not actually true…Sort of makes you wonder what else polar bear experts “believe” to be true but actually isn’t.”

Believing that sea ice declines predicted by climate modelers 50 to 100 years into the future have more credibility than gazing into a crystal ball is high on my list of “beliefs” held by Arctic biologists that will soon tumble to the facts.

References
Cameron, M. F., Bengtson, J. L., Boveng, J. K., Jansen, J. K., Kelly, B. P., Dahle, S. P., Logerwell, E. A., Overland, J. E., Sabine, C. L., Waring, G. T. and Wilder, J. M. 2010. Status review of the bearded (Erignatha barbatus). NOAA Technical Memorandum NMFS-AFSC-211.
www.afsc.noaa.gov/Publications/AFSC-TM/NOAA-TM-AFSC-211.pdf

Kelly, B. P., Bengtson, J. L., Boveng, P. L., Cameron, M. F., Dahle, S. P., Jansen, J. K., Logerwell, E. A., Overland, J. E., Sabine, C. L., Waring, G. T. and Wilder, J. M. 2010. Status review of the ringed seal (Phoca hispida). NOAA Technical Memorandum NMFS-AFSC-212.
www.afsc.noaa.gov/Publications/AFSC-TM/NOAA-TM-AFSC-212.pdf

Kovacs, K. and Lowry, L. (IUCN SSC Pinniped Specialist Group) 2008. Erignathus barbatus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . Downloaded on 29 December 2012. http://www.iucnredlist.org/details/8010/0

Kovacs, K., Lowry, L. and Härkönen, T. (IUCN SSC Pinniped Specialist Group) 2008. Pusa hispida. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . Downloaded on 29 December 2012. http://www.iucnredlist.org/details/41672/0

Lunn, N.J., Schliebe, S., and Born, E.W. (eds.). 2002. Polar Bears: Proceedings of the 13th working meeting of the IUCN/SSC Polar Bear Specialists Group, 23-28 June , 2001, Nuuk, Greenland. Gland, Switzerland and Cambridge UK, IUCN. http://pbsg.npolar.no/en/meetings/

Unger, Z. 2012. The truth about polar bears. Canadian Geographic December:28-42. http://www.canadiangeographic.ca/magazine/dec12/polar_bears.asp

Comments are closed.