Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research Confirms Bottom-Feeding Behavior of Humpback Whales

31.10.2013
Humpback whales are known for the complexity of their feeding techniques, which include “trapping” krill and other prey within bubble nets they produce and gulping up to two-thirds their weight in prey-laden water.

Now, scientists have confirmed that humpback whales in the southern Gulf of Maine are spending more feeding time on the ocean floor than in any of these other feeding behaviors. Because entanglement in fishing gear is a major risk to humpbacks, these findings have implications on bottom-set gear like those used in lobster traps.


Caption: Humpback whale with a scrape on its jaw. Scientists say injuries such as this one are sometimes a result from bottom-feeding. Credit: NOAA/Stellwagen Bank National Marine Sanctuary

“Humpbacks have not been known as bottom-feeders, yet this is their dominant feeding mode in this region,” says University of New Hampshire professor of data visualization Colin Ware, lead author of a paper published in the journal Marine Mammal Science. “You’ve got this prominent species, and until now nobody knew how they were doing most of their feeding.”

Ware, of UNH’s Center for Coastal and Ocean Mapping, and his collaborators, including David Wiley of the Stellwagen Bank National Marine Sanctuary of the National Oceanic and Atmospheric Administration (NOAA) and Ari Friedlaender of Duke University Marine Laboratory and Pratt School of Engineering, gathered data from 52 humpback whales in the Stellwagen Bank National Marine Sanctuary and the Great South Channel near Cape Cod, Mass.

By affixing DTAGs – synchronous motion and acoustic recording tags – to the whales’ backs via four suction cups, the researchers could track for the first time the movements of the whales below the ocean’s surface. TrackPlot, a custom software tool developed by Ware, translated the tags’ data into a three-dimensional ribbon that illustrated the whales’ paths as they repeatedly dove to the bottom of the ocean, rolled onto their sides, tilted their heads down, and feasted on sand lance, a favorite food that is abundant there.

From this data, collected between 2004 and 2009, Ware and his collaborators identified three distinct types of behavior during what they call bottom side-roll feeding: simple side-rolls, side-roll inversions, and repetitive scooping. The tag data confirms the bottom-feeding that scientists had suspected from visible scarring along some whales’ jaws.

Not only did the data show that these humpbacks, “by far the most acrobatic of all baleen whales,” Ware says, were performing bottom side-rolls and seafloor scooping, it indicates that this bottom feeding does not include lunging, previously assumed to be the humpbacks’ primary feeding behavior.

In lunge feeding, whales accelerates to propel water full of prey into their enlarged mouths; they then filter the water out through the hair-like filaments of their baleens and retain the prey. Tag data showed that the bottom-feeding humpbacks were moving at too low a speed to characterize this behavior as lunge feeding.

While a Crittercam™ – a National Geographic Society video camera that gives a whale’s-eye view -- attached to a humpback provides additional insight into the whales’ time at the seafloor, Ware cautions that there’s plenty to learn about what the whales are doing in the deep.

“The big mystery is we still don’t know exactly how they’re feeding. We don’t know the mechanism,” he says.

The study, “Bottom side-roll feeding by humpback whales (Megaptera novaeangliae) in the southern Gulf of Maine, U.S.A,” was first published online in Marine Mammal Science in July 2013. In addition to Ware, Wiley and Friedlaender, co-authors are Mason Weinrich of the Whale Centre of New England, Elliott L. Hazen of Duke and NOAA SWFSC, Alessandro Bocconcelli of Woods Hole Oceanographic Institute, Susan E. Parks of Syracuse University, Alison K. Stimpert of the Naval Postgraduate School, Mike A. Thompson of Stellwagen Bank National Marine Sanctuary, and Kyler Abernathy of National Geographic Television.

Funding was provided by the Office of Naval Research (ONR N0014091601 for TrackPlot development and N00014-08-0630 for field work and analysis), NOAA (NA05NOS4001153), the National Oceanographic Partnership Program, the Stellwagen Bank National Marine Sanctuary, and the Office of National Marine Sanctuaries.

The University of New Hampshire, founded in 1866, is a world-class public research university with the feel of a New England liberal arts college. A land, sea, and space-grant university, UNH is the state's flagship public institution, enrolling 12,300 undergraduate and 2,200 graduate students.

Photograph available to download: http://sanctuaries.noaa.gov/news/press/2013/whale_scrape.jpg
Caption: Humpback whale with a scrape on its jaw. Scientists say injuries such as this one are sometimes a result from bottom-feeding.

Credit: NOAA/Stellwagen Bank National Marine Sanctuary

Image available to download: http://sanctuaries.noaa.gov/news/press/2013/trackplot.jpg
Caption: In this 3D computer visualization from UNH’s Data Visualization Research Lab, the roller coaster-like movement of a tagged humpback whale in Stellwagen Bank National Marine Sanctuary is captured over a nearly two-hour period. The whale traveled at depths ranging from 30 to 150 feet deep. The red and blue triangles along the ribbon show the whale's powerful fluke, or tail fin, strokes that propel it through the water. The yellow sections along the ribbons indicate where bottom side-roll feeding occurs.

Credit: Colin Ware, University of New Hampshire Center for Coastal and Ocean Mapping

Watch the Crittercam™ video: http://video.nationalgeographic.com/video/news/animals-news/humpback-whales-bottom-feeding-vin/?source=videomostwatched

Beth Potier | EurekAlert!
Further information:
http://www.unh.edu

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>