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 Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto

nachricht Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>