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
Credit: NOAA/Stellwagen Bank National Marine SanctuaryImage available to download: http://sanctuaries.noaa.gov/news/press/2013/trackplot.jpg
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!
Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH
Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences