Underwater gliders may change how scientists track fish

Jun 22, 2010
A scientist takes an underwater photo of one of the underwater gliders. UAF researchers recently successfully tested the use of the autonomous underwater vehicles for tracking tagged fish. Credit: Photo courtesy of Hank Statscewich

Tracking fish across Alaska's vast continental shelves can present a challenge to any scientist studying Alaska's seas. Researchers at the University of Alaska Fairbanks have successfully tested a possible solution in the form of underwater gliders.

Last month, Peter Winsor, associate professor of physical , and Andrew Seitz, assistant professor of fisheries, tested the use of autonomous underwater vehicles, called gliders, for tracking tagged fish. Winsor and Seitz suspended acoustic tags, usually implanted in fish, at different depths along a buoy line near Juneau. They then deployed two gliders fitted with an acoustic listening device to "hear" the signals from the tags.

Winsor and Seitz say these are the first gliders to be deployed in Alaska with an acoustic monitoring device to track tagged fish.

Each is about five feet long and flies like an airplane through the water in an up-and-down motion. They are propelled using an internal bladder that works much like a fish's swim bladder. When the bladder expands, the glider moves toward the surface. When it contracts, it moves toward the seafloor.

"They convert changes in water depth into forward movement," said Seitz.

The gliders move at a speed of nearly one mile per hour and can operate for up to three months. According to Winsor, the gliders can cover thousands of miles of ocean. At the surface, the glider transmits data, including its location and oceanographic readings, directly to scientists.

"With the gliders, we not only learn about where the fish go, but we can also measure the physical, chemical and biological environment of the ocean at the same time," said Winsor.

Traditional methods of tracking tagged fish include using a ship equipped with an acoustic listening device, or by using what scientists call a "listening line," which is a series of hydrophones attached to the .

"The problem with using hydrophones is that they stay in one place and the tagged fish have to move near enough to the hydrophones to be detected," said Seitz. "This can create big geographic gaps in your data, especially in the vast oceans surrounding Alaska."

Seitz and Winsor say that the gliders can be programmed to follow tagged fish. The technology is ideal for Alaska waters because the gliders can cover large distances and are much less expensive than using a ship or sets of hydrophones. Scientists are planning to use the gliders to gather oceanographic information in the Chukchi Sea.

Explore further: Clean air: Fewer sources for self-cleaning

add to favorites email to friend print save as pdf

Related Stories

'Ocean glider' home after two-month voyage

Apr 16, 2009

Scientists are celebrating the first successful deployment and retrieval in Australia of a remotely controlled, deep ocean-going robotic submarine destined to play a central role in measuring changes in two ...

Underwater robot launched from Bermuda to cross Gulf Stream

Mar 25, 2005

A small autonomous underwater vehicle, or AUV, named Spray was launched yesterday about 12 miles southeast of Bermuda. The two-meter-(6-foot)-long orange glider with a four-foot wingspan will slowly make its way northwest, ...

Deep-sea sharks wired for sound

Apr 09, 2008

Deep-sea sharks have been tagged and tracked and their habitats precisely mapped in world-first research to test the conservation value of areas closed to commercial fishing.

Recommended for you

Clean air: Fewer sources for self-cleaning

12 hours ago

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

There's something ancient in the icebox

12 hours ago

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Image: Grand Canyon geology lessons on view

19 hours ago

The Grand Canyon in northern Arizona is a favorite for astronauts shooting photos from the International Space Station, as well as one of the best-known tourist attractions in the world. The steep walls of ...

First radar vision for Copernicus

19 hours ago

Launched on 3 April, ESA's Sentinel-1A satellite has already delivered its first radar images of Earth. They offer a tantalising glimpse of the kind of operational imagery that this new mission will provide ...

User comments : 0

More news stories

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...