Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Prey-tell: Why Right Whales Linger in the Gulf of Maine

27.04.2011
As they might with most endangered animals, scientists consider the whereabouts and activities of right whales extremely important. “It is helpful to know where they go, why they go there and what they do when they’re there,” says Mark F. Baumgartner of the biology department at the Woods Hole Oceanographic Institution (WHOI).

Baumgartner and his colleagues studied the behavior of right whales and sei whales—both endangered species of baleen whales—in the waters of the Gulf of Maine to the east of Nantucket. They found that the location, the length of stay, and perhaps the very abundance of the whales may be dependent on an interesting vertical migration pattern by the copepods on which the whales feed. It seems to be a case, he said, of “how the behavior of the prey influences the behavior of the whales.”

The algae-eating copepod, Calanus finmarchicus, appears to migrate up and down in the water column to avoid being eaten by predators such as herring and sand lance. Since these fish need to see their prey in order to feed, copepods often remain at depths where sunlight will not penetrate during the daytime. Under cover of night, they leave this deep, dark refuge, swim to the surface, and feed on algae in relative safety.

In turn, this pattern, the scientists report in a recent issue of the journal Marine Ecology Progress Series, has a “dramatic impact” on the behavior and whereabouts of the whales. They found that right whales, which are capable of feeding at depths of 450 to 600 feet below the surface, continued to stay in the area and feed on copepods deep in the water column during the day. The sei whales, on the other hand, were “significantly less abundant” when the copepods displayed vertical migration. Unlike the right whales, the sei whales probably cannot feed at depth during the day, so they may leave the area in search of better feeding conditions elsewhere.

For reasons not well understood, the critically endangered right whale is vulnerable to being hit by ships while at the surface. Baumgartner points out that nighttime may prove particularly dangerous for right whales as they feed on copepods that have migrated to the surface, yet captains piloting ships in the dark have no way to see and avoid the whales.

“Our study also helps us understand why right whales stick around in this area, from about mid April to mid June,” Baumgartner said. Because of their ability to feed below the surface, “they are able to out-compete the herring” for food, he said.

It had been thought that the recovery of herring stocks in the last decade might further threaten the right whale by depleting its food supply, Baumgartner said. But these latest observations—along with a rise in the North Atlantic right whale population from roughly 300 to 400 since 1999—suggest that herring recovery does not threaten the right whale population, he said.

At the same time, the herring and sand lance, by inducing the copepods’ vertical migration behavior, “are likely influencing the distribution and abundance of sei whales” in that area, the researchers report. However, since the sei whale population numbers in the thousands, Baumgartner said their tendency to go elsewhere to look for food is not as great a concern as it would be for the right whale.

“The good news is that the recovery of herring stocks is not going to be a problem for the right whale population,” Baumgartner said. “The bad news is that if the right whales are feeding at the surface at night, they are at greater risk for ship strikes than we had thought earlier.”

The study was conducted during the spring seasons of 2005, 2006 and 2007.

Baumgartner was joined in the study by Nadine S.J. Lysiak of WHOI and researchers from UMass Boston and the NOAA Northeast Fisheries Science Center in Woods Hole.

Funding was provided by NOAA, the Office of Naval Research, the WHOI Ocean Life Institute, and the WHOI John E. and Anne W. Sawyer Endowed Fund.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.

Media Relations | EurekAlert!
Further information:
http://www.whoi.edu
http://www.whoi.edu/page.do?pid=7545&tid=282&cid=98429&ct=162

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>