|An adult female walrus. Photo by Ryan Kingsbery, U.S. Geological Survey.|
Tipped off by reports from the local community, NOAA scientists were the first to photograph from the air and document thousands of burly, mustachioed mammals lounging on the shore near Pt. Lay, Alaska this summer.
The team's small airplane carried digital cameras for documenting whale sightings, so they took aerial photos of the crowded beach and shared them with colleagues at partner agencies. It turned out those photos were evidence of a relatively new phenomenon. Due to loss of sea ice in offshore areas, Pacific walruses are foraging in more coastal areas and using beaches for resting, or hauling out.
The number of walruses at the Pt. Lay haulout keeps growing. Estimates from the photos are 1,500 to 4,000 animals when first seen on 12 September, and 5,500 to 8,000 on 22 September. On 27 September, biologists report that there were approximately 10,000 walruses.
Every year, a team from the Alaska Fisheries Science Center's National Marine Mammal Laboratory surveys the Alaskan Arctic from a small airplane to study the distribution and abundance of marine mammals. These flights are part of the Aerial Surveys of Arctic Marine Mammals (ASAMM) project funded and co-managed by the Bureau of Ocean Energy Management Environmental Studies Program. The aim of the project is to monitor the patterns of marine mammal density in areas of the Arctic where oil and gas exploration may take place.
|An aerial photograph of an estimated 8,000 walruses taken near Pt. Lay, Alaska, 22 September 2013. Photo by Stan Churches.|
Megan Ferguson from NOAA Fisheries, the ASAMM Project Coordinator, explains: "NOAA's research typically doesn't extend to studying walruses. Among the federal agencies, the U.S. Geological Survey and the U.S. Fish and Wildlife Service conduct most of the walrus research, and the species is managed by USFWS. It's exciting for ASAMM's marine mammal observers and pilots to be able to assist other agencies by collecting valuable data on walruses, while carrying out our primary mission of monitoring the whales and porpoises in the northeastern Chukchi and western Beaufort Seas.
"This is turning out to be a really good year. In addition to photographing the walrus haulout area, NOAA scientists documented more bowhead whales, including calves and feeding adults, in the Beaufort Sea this summer compared to 2012. We are also seeing more gray whale calves in the Chukchi Sea than we have in recent years."
Large walrus haulouts along the Alaskan coastline in the northeastern Chukchi Sea are a relatively new phenomenon. In the past, walruses used sea ice offshore in the northern Chukchi Sea as resting platforms in between dives. On the shallow bottom of the Chukchi, the walruses feed on clams, snails and worms during the summer and autumn. The first large haulout along the shoreline near Pt. Lay formed in 2007, coinciding with an unprecedented loss of sea ice across the Chukchi Sea. During 2008 and 2012, remnants of sea ice offshore in the Chukchi Sea were sufficient for walruses to rest on between foraging dives. Haulouts on land formed in northwestern Alaska near Icy Cape and Cape Lisburne in 2009 and near Pt. Lay in 2010, 2011 and 2013.
|Cynthia Christman photographing marine mammals from inside the ASAMM survey aircraft. Photo by Vicki Beaver.|
USGS Wildlife Biologist Tony Fischbach elaborated on this multi-agency collaboration. "Aerial photographs taken by NOAA scientists on the ASAMM team provide a context for the USGS walrus tracking studies, and allow USGS to make mission critical logistics decisions on when to deploy our teams and when to conduct our work with walruses on shore. The ASAMM team efforts are invaluable, as we all seek to understand how walruses are adjusting their behavior and movements in response to the loss of summer sea ice."
USFWS Wildlife Biologist Joel Garlich-Miller said, "The coastal aerial surveys carried out by the ASAMM team provide valuable information about the timing and location of coastal haulout formation on the Chukchi Sea coast of Alaska. The USFWS and coastal communities use in-season reports of walrus haulouts to establish and adapt protection measures to minimize disturbances from aircraft overflights and ship traffic. The coastal surveys also provide valuable baseline information about important coastal habitats for walruses, which can be used to evaluate and mitigate potential impacts of proposed projects in the Chukchi Sea region."
By Lt. Fionna Matheson, NOAA Corps with Megan Ferguson, Ph.D., National Marine Mammal Laboratory