Subscribe to our free daily newsletters
. 24/7 Space News .

Subscribe to our free daily newsletters

Eavesdropping on Bering Strait marine mammals
by Staff Writers
Washington DC (SPX) Nov 09, 2015

File image.

Climate change hasn't been kind to the Arctic Circle, as evidenced by the decrease of seasonal ice in the area and the encroachment of temperate species. One way to monitor impacts to the ecosystem is by observing the changes in occurrence or distribution of sea birds and marine mammals.

So a team of researchers is listening to the sounds made by marine mammals within the Arctic to monitor their presence year round. During the Acoustical Society of America's Fall 2015 Meeting, being held Nov. 2-6, in Jacksonville, Fla., Kathleen Stafford, principal oceanographer for the Applied Physics Lab at the University of Washington, will describe their work and the passive acoustic monitoring techniques involved.

The team is interested in determining the seasonal and inter-annual occurrence of summer whales in the gateway to the Pacific Arctic to discover if they are spending more time within the region.

This is also key to the native Yupik and Inupiat, who inhabit the Bering Strait region and rely heavily on marine mammals for subsistence. "Changes in the environment cause changes in animal distributions or seasonal occurrences that can affect access to subsistence species," said Stafford.

To do this, the researchers use underwater microphones called hydrophones on oceanographic moorings to listen for the sounds made by marine mammals.

"This passive acoustic monitoring technique allows us to detect the presence of vocalizing marine mammals continuously - 24 hours per day - in all weather conditions, over periods of weeks to months, over distances of 20 to 30 kilometers, and is a proven sampling method in the waters offshore Alaska," explained Stafford.

The microphones record data at a sample rate of 8kHz, so the group listens up to 4kHz - for scale, the highest note on a normally tuned, standard piano is 4.186 kHz - to include signals produced by large whales like fins, humpbacks, bowheads and killer whales, as well as pinnipeds such as bearded seals and walrus. The data is recorded on a "duty cycle" of 15 minutes per hour to enable the instruments to continue to record for as long as possible.

This provides "a window into Arctic and sub-Arctic species in regions and seasons in which other more traditional - visual - methodologies aren't feasible," Stafford added. "The Arctic is still very dark and cold in the dead of winter, and can be stormy and foggy at other times. And although we can't directly observe it, by eavesdropping under the ice, we can hear quite a lot of animal activity going on."

Once the data is recorded, the researchers need to retrieve the instruments. They then examine spectrograms - pictures of frequency and amplitude over time - to visually document the presence of different species.

One of the biggest surprises they've encountered so far? Humpback whales singing in the Chukchi Sea through the fall - a male reproductive display previously thought to be confined to tropical breeding grounds.

The team also confirmed that summer whales are in the Arctic throughout the open water season now. "Summer whales have always occurred north of Bering Strait, although not in great numbers, and not in September, October, or November, when we hear them now," Stafford said.

Stafford and colleagues will continue their long-term data collection to document the inter-seasonal and inter-annual presence of vocal marine mammals in the Bering Strait by integrating oceanographic drivers - sea ice, temperature, current speed and direction, and water mass properties - with acoustic detections.

"By coupling acoustic recorders with concurrently collected oceanographic data, we can explore relationships between the physical and biological context of residence in or migration through the Bering Strait, and quantify the animals' fluxes in this gateway to the Arctic in a manner that allows the investigation of seasonal and annual changes," she added.

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
Acoustical Society of America
Beyond the Ice Age

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Previous Report
Arctic attracting new military scrutiny
Fairbanks, United States (AFP) Oct 31, 2015
In 2013, US President Barack Obama said the Arctic was "peaceful, stable, and free of conflict" as he laid out a national strategy for the region. But just two years later, the rapid retreat of ocean ice cover, a newly emboldened Russia and the covetous gaze of nations keen to exploit new shipping lanes and vast mineral wealth are putting the Arctic's longstanding stability under pressure. ... read more

Gaia's sensors scan a lunar transit

SwRI scientists explain why moon rocks contain fewer volatiles than Earth's

All-female Russian crew starts Moon mission test

Russian moon mission would need 4 Angara-A5V launches

Amnesia Event Slows Down Opportunity Robotic Arm Work

Swiss Camera Leaves for Mars

NASA mission reveals speed of solar wind stripping Martian atmosphere

Martian desiccation

Orion Service Module Stacking Assembly Secured For Flight

Global partnerships in orbit support economic growth on and off the Earth

Magic plant discovery could lead to growing food in space

NASA Armstrong Hosts Convergent Aeronautics Solutions Showcase

China's self-developed Mars probe to be on show

Could Sino-U.S. cooperation bring the Martian home?

China's scientific satellites to enter uncharted territory

Declaration approved to promote Asia Pacific space cooperation

US astronauts dodge ammonia on risky spacewalk

UK astronaut dreams of heavenly Christmas pudding

NASA drops Boeing from race for $3.5 billion cargo contract

Space Station offers valuable lessons about life support systems

Commercial Spaceflight Gets A Boost With Latest Congressional Moves

The 10th Arianespace mission of 2015 is "go" for its Ariane 5 liftoff next week

USAF releases first Booster Propulsion Technology Maturation BAA Award

SpaceLoft demonstrates capability to eject separate payloads requiring independent re-entry

Distant world's weather is mixed bag of hot dust and molten rain

Disk gaps don't always signal planets

Finding New Worlds with a Play of Light and Shadow

Did Jupiter Expel A Rival Gas Giant

New ORNL catalyst features unsurpassed selectivity

Cyclic healing removes defects in metals while maintaining strength

Microscopy unveils lithium-rich transition metal oxides

Scanning reveals anomalies in Great Pyramid at Giza

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement