Whales and waves : humpback whale foraging response and the shoaling of internal waves at Stellwagen Bank
Starczak, Victoria R.
da Silva, Jose C. B.
Helfrich, Karl R.
Thompson, Michael A.
Wiley, David N.
MetadataShow full item record
We tested the hypothesis that humpback whales aggregate at the southern flank of Stellwagen Bank (SB) in response to internal waves (IWs) generated semidiurnally at Race Point (RP) channel because of the presence of their preferred prey, planktivorous fish, which in turn respond to zooplankton concentrated by the predictable IWs. Analysis of synthetic aperture radar (SAR) images indicates that RP IWs approach the southern flank of SB frequently (∼62% of the images). Published reports of whale sighting data and archived SAR images point to a coarse spatial coincidence between whales and Race Point IWs at SB's southern flank. The responses of whales to IWs were evaluated via sightings and behavior of humpback whales, and IWs were observed in situ by acoustic backscatter and temperature measurements. Modeling of IWs complemented the observations, and results indicate a change of ∼0.4 m/s in current velocity, and ∼1.5 Pa in dynamic pressure near the bottom, which may be sufficient for bottom fish to detect the IWs. However, fish were rare in our acoustic observations, and fish response to the IWs could not be evaluated. RP IWs do not represent the leading edge of the internal tide, and they may have less mass-transport potential than typical coastal IWs. There was large interannual variability in whale sightings at SB's southern flank, with decreases in both numbers of sightings and proportion of sightings where feeding was observed from 2008 to 2013. Coincidence of whales and IWs was inconsistent, and results do not support the hypothesis.
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 120 (2015): 2555–2570, doi:10.1002/2014JC010564.
Showing items related by title, author, creator and subject.
Bottom side-roll feeding by humpback whales (Megaptera novaeangliae) in the southern Gulf of Maine, U.S.A Ware, Colin; Wiley, David N.; Friedlaender, Ari S.; Weinrich, Mason T.; Hazen, Elliott L.; Bocconcelli, Alessandro; Parks, Susan E.; Stimpert, Alison K.; Thompson, Michael A.; Abernathy, Kyler (John Wiley & Sons, 2013-07-24)Humpback whales (Megaptera novaeangliae) are known for the variety and complexity of their feeding behaviors. Here we report on the use of synchronous motion and acoustic recording tags (DTAGs) to provide the first detailed ...
Watkins, William A.; Daher, Mary Ann; George, Joseph E.; Haga, Scott H. (Woods Hole Oceanographic Institution, 2000-12)The seasonal distribution of calling ble whales (Balaenoptera musculus), fin whales (B. physalus), and singing humpback whales (Megaptera novaeangliae) has been analyzed from acoustic data recorded by the U.S. Navy Sound ...
Biassoni, Nicoletta; Miller, Patrick J. O.; Tyack, Peter L. (Woods Hole Oceanographic Institution, 2000-05)The singing behavior of humpback whales exposed to SURTASS-LFA sonar was monitored in Hawaii during March 1998. An observation vessel towing a hydrophone array followed individual singers continuously recording their songs ...