Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scripps Oceanography Research Studies Shed New Light on Blue Whales and Their Calls

01.03.2007
Acoustics data help researchers account for worldwide population distributions; Recording tags, tissue samples and sightings help define context for whale calls

Using a variety of new approaches, scientists at Scripps Institution of Oceanography at UC San Diego are forging a new understanding of the largest mammals on Earth.

In one recently published study on blue whales, Scripps researchers used a combination of techniques to show for the first time that blue whale calls can be tied to specific behavior and gender classifications. In a separate study, researchers used recordings of blue whale songs to determine the animal's population distributions worldwide.

While the specific function of songs and calls produced by whales remains a mystery to a large degree, the sounds are thought to mediate social interactions between the animals.

... more about:
»Pacific »Population »Scripps »Southwest

The first study, led by Scripps postdoctoral researcher Erin Oleson and Scripps scientist John Hildebrand, describes the behavioral context of calls produced by eastern North Pacific blue whales. Few researchers have attempted to link sound production with specific behaviors or environmental conditions to attempt to determine the significance of whale calls.

"This is the first study that has been able to study the calls by directly observing the animal while it is calling and gathering key information such as depth and body orientation—getting a sense of what the animal is doing underwater," said Oleson. "Once you understand the context of specific types of sounds, then you can use those sounds to infer something about what they are doing when you are not there to actually see them doing it."

Using a blend of approaches that included attaching miniature acoustic recording tags to whales, Oleson and her colleagues were able to find clear patterns tied to whale behavior, sex type and group size with specific call types. The tags included the National Geographic "Crittercam," an integrated video-camcorder and data-logging system, and the "B-probe," an electronic data-logging tag attached to the animal via suction cup. Those data were supplemented with analysis of whale tissue samples and visual observations from ships.

The researchers found that only males produced sounds known as "AB" calls while "D" calls were heard from both sexes, typically during foraging. The researchers note in the paper, published in the January 25 issue of the Marine Ecology Progress Series journal, that the sex bias evident in AB callers suggests that those calls probably play a role in reproduction.

Oleson hopes such call and behavior information will eventually be used for better understanding whale habitats and calculating species abundances.

The second study, published in a recent issue of the Journal of Cetacean Research Management, describes the first attempt at determining worldwide blue whale populations by analyzing nuances of their songs.

Hildebrand and his colleagues used acoustic recordings from around the world, including data from his own instrument deployments and recordings from other scientists and the U.S. Navy, to create a new map that geographically categorizes blue whale species types into nine regions around the world based on their song "dialects."

While certain regional designations are concentrated in areas close to one coastal area, such as the map's "type 1" classification primarily off the North American coast, others, such as "type 4," are spread over broad areas, in this case throughout the Northern Pacific Ocean.

The blue whale saw its numbers dwindle dangerously before whaling moratoria were enacted. Now the new study may become a tool for representing its true population stocks. The paper suggests that the stock structures of blue whales, traditionally based on International Whaling Commission boundaries, should instead be reconstructed based on song, which would more accurately represent their true population distributions.

"By listening to the animals, you can tell something about the areas in which they are interacting to breed and that's important to know for managing and conserving the animals," said Hildebrand, who coauthored the paper with Mark McDonald of Whale Acoustics and Sarah Mesnick of the Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration.

Type Region

1 Northeast Pacific (NEP)
2 Southeast Pacific (SEP)
3 Southwest Pacific (SWP)
4 North Pacific (NP)
5 North Atlantic (NA)
6 Southern Ocean (SO)
7 North Indian (NI)
8 Southeast Indian (SEI)
9 Southwest Indian (SWI)
Coauthors of Oleson's study, in addition to Hildebrand and McDonald, include John Calambokidis of the Cascadia Research Collective, William Burgess of Greeneridge Sciences and Carrie LeDuc of the Southwest Fisheries Science Center.

The studies were supported by the U.S. Navy's Strategic Environmental Research and Development Program, the Chief of Naval Operations, the Office of Naval Research, the National Science Foundation Office of Polar Programs, the Southwest Fisheries Science Center, the Tagging of Pacific Pelagics Program and the Center for Integrated Marine Technology at UC Santa Cruz.

Mario Aguilera | EurekAlert!
Further information:
http://scrippsnews.ucsd.edu/article_detail.cfm?article_num=774

Further reports about: Pacific Population Scripps Southwest

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>