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Alaska: Federal Funding Announced for Northern Fur Seal Study |
| July 15, 2004 |
Source: Vancouver Aquarium Marine Science Centre
 | The study will focus on northern fur seal rookeries like the one pictured here, where mating and birthing take place.
Photo: National Marine Mammal Laboratory/NOAA |
The National Ocean and Atmospheric Administration (NOAA) has approved funding for a multi-year study of northern fur seal populations in Alaska. The study, funded to the tune of $244,000, will be carried out by scientists from the Alaska Fisheries Science Centre and will focus on fur seal mating and birthing grounds, known as rookeries.
It may also determine why the fur seal pup population has boomed on Bogoslof Island, a small island located at the western tip of the Aleutian chain, while declining on the Pribilof Islands, roughly 300 kilometres to the north.
“The Bogoslof rookery is important to the status and sustainability of fur seals in Alaska,“ said NOAA scientist Rolf Ream. “With the grant money we hope to determine why the population on Bogoslof has fared so well.
“While on Bogoslof conducting this research,” he added, “we will also have the opportunity to obtain a new population estimate to see if the numbers of fur seals have continued to grow at such an extraordinary rate.”
Bogoslof Island showed little to no habitation by northern fur seals prior to the 1970’s. The island’s fur seal population exploded in the following decades, growing annually by 59 percent. The most recent Bogoslof Island survey, taken in 1997, tallied 5,096 pups.
On the more northern Pribilof Islands, however, northern fur seal numbers have mysteriously declined since 1998. Scientists will begin the next Pribilof Island fur seal census in August of 2004 and hope to find a reason for the decline.
NOAA scientists begin studying fur seal populations in the Pribilofs in mid to late July, after most of the adults have arrived at the rookeries for mating and birth. Scientists return to the rookeries throughout the year to attach and collect satellite tags. They also take “condition” measurements in an attempt to estimate the fatty acids, measurement, weight, body composition and milk intake of female fur seals.
Although the sporadic distribution of northern fur seals around the world makes it difficult for scientists to accurately estimate their populations, it is commonly agreed that a majority of the world’s fur seals occur in Alaska. Because adult fur seals are often at sea and difficult to study, scientists take a census of seal pups at the Pribilof and Bogoslof rookeries to examine biological trends and to estimate the total number of fur seals in Alaska.
Northern fur seals are listed as a depleted species under the federal Marine Mammal Protection Act. Hunted to near-extinction during the early 1800’s, Alaskan populations were spared in 1911 by an international ban on fur seal hunting after their populations were observed to be in severe decline. However, fur seal hunting on land was only banned in the Pribilof Islands in 1984, and Alaska’s indigenous peoples still harvest a small number of fur seals for subsistence purposes.
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