Long goodbye to Steller sea lions: creatures are disappearing

May 22, 2001

GALVESTON - It's an act that would rival the best work of Siegfried and Roy: How are 2,000-pound Steller sea lions disappearing so quickly?

The Steller sea lion, the largest of all sea lions, has suffered declining numbers that threaten its existence. In some parts of the world, its numbers are now only 15 percent of what they were in 1970, which is why it has been placed on the endangered species list.

Texas A&M University at Galveston researchers Markus Horning and Jo-Ann Mellish are on a quest to find out why the animal's future is in doubt, and with the help of an $800,000 National Science Foundation grant and a $1 million National Marine Fisheries Service grant, they may be able to unravel at least some of the riddle.

Horning will use satellite-linked, close-range imaging to monitor the lumbering creatures, whose numbers are quickly dwindling, especially around the Gulf of Alaska and near the Aleutian Islands, ground zero for many Stellers.

Horning will place several digital cameras with transmitters near Steller breeding grounds. He hopes to get an accurate census count of just how many Stellers are out there, and with help of the images, calculate the body size of those photographed.

"The body size will tell us the approximate age of the animal, which in turn can tell us several things," Horning explains. "The body size can tell us if the Steller is getting an adequate food supply. If no young Stellers appear to be growing much larger, that might indicate some sort of nutritional stress, such as not enough food supply to begin with. "Also, the percent of fat stored in the animal can tell us about its eating habits and its food supply."

A possible cause of less-than-ideal food supply: overfishing in the area.

Researchers have for years believed that commercial fishermen in the area have netted huge supplies of pollock and mackerel, the Stellers' primary food source. Fewer fish ultimately could lead to fewer Stellers, a cycle that may have gotten out of sync for the last 30 years.

"If there is nutritional stress, is it because of overfishing? That's one big question we hope to answer," Horning adds. There are two kinds of Stellers - the Eastern stock and the Western stock, so named because they inhabit those areas of the Gulf of Alaska. The Eastern stock population has remained stable, Horning says.

But the Western stock has diminished greatly - from 170,000 in 1970 to only about 25,000 today. Its decline parallels those of other endangered animals in the area, such as the sea otter, harbor seal and Orca whale.

"The Gulf of Alaska and Behring Sea are two of the most important ecosystems in the world," Horning adds. "We hope to find some answers. The decline in Steller sea lions and other species could be potentially devastating to the area."
Contact: Markus Horning or Jo-Ann Mellish at 409-740-4541.

Texas A&M University

Related Body Size Articles from Brightsurf:

Body size of the extinct Megalodon indeed off the charts in the shark world
A new study shows that the body size of the iconic gigantic or megatooth shark, about 15 meters (50 feet) in length, is indeed anomalously large compared to body sizes of its relatives.

Weight gainers more likely to underestimate their true body size
People with obesity who gain weight have a tendency to perceive their own body size as smaller than it actually is compared to those who maintain a stable weight, according to new research following more than 2,000 people with obesity from the Swedish Obese Subjects (SOS) study over 10 years.

Whole body ownership is not just the sum of each part of the body
Differences between whole body and body part ownership were clarified using scrambled body stimulation in a virtual environment, wherein the observer's hands and feet were presented in randomized spatial arrangements.

'Like a video game with health points,' energy budgets explain evolutionary body size
Budgeting resources isn't just a problem for humans preparing a holiday dinner, or squirrels storing up nuts for the winter.

Lifestyle coaching proves effective in decreasing body fat and waist size
Losing weight during and after menopause is not easy, but it's not impossible, either.

Short-term study suggests vegan diet can boost gut microbes related to body weight, body composition and blood sugar control
New research presented at this year's Annual Meeting of the European Association for the Study of Diabetes (EASD) in Barcelona, Spain (Sept.

Waist size, not body mass index, may be more predictive of coronary artery disease
For years, women have been told that weight gain could lead to heart disease.

Memory research: Fruit flies learn their body size once for an entire lifetime
Drosophila melanogaster develops stable long-term memory for its body size and reach through motion parallax while walking.

Size matters: New data reveals cell size sparks genome awakening in embryos
Transitions are a hallmark of life, and so there is a transition during early development when an embryo undergoes biochemical changes, switching from being controlled by maternal molecules to being governed by its own genome.

Size is everything
The susceptibility of ecosystems to disruption depends on a lot of factors that can't all be grasped.

Read More: Body Size News and Body Size Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.