Why Don't Right Whales Respond to the Noise of an Oncoming Vessel?
Right whales seem to be able to evade slow, small vessels, but appear to be oblivious to large ships that too often strike and kill them.
Peter Tyack's lab has been studying factors affecting the ability of
North Atlantic Right Whales to avoid lethal collisions with vesselsa
key threat to the population's recovery. Experiments have shown that
right whales can very precisely detect and locate sounds, yet the
whales fail to respond to the noise of approaching vessels. In subsequent
experiments, the researchers tested alarm stimuli designed to alert
whales of danger and found that 5 of 6 whales responded to the alarms
by surfacing quickly and swimming rapidly at the surface.
Should ships be equipped with alarms to alert right whales? The whales' strong response to the alarm raises more questions than it answers for policy makers seeking to reduce whale-vessel collisions. By swimming to the surface, right whales actually increase their risk of collision with vessels. Future research by Tyack's group aims to evaluate whether alarm stimuli--in concert with other strategies perhapscould help reduce the risk of vessel collisions.
A senior scientist in the Biology Department of the Woods Hole Oceanographic Institution, Dr. Peter Tyack focuses his research on social behavior and acoustic communication of marine mammals. Tyack has conducted many studies to evaluate the effects of ocean noise on marine mammals and has served on two committees of the National Academy of Sciences investigating this topic. He collaborates closely with engineers at WHOI developing methods to follow the behavior of marine mammals throughout their dive cycle. The culmination of this effort is a tag that records everything a whale hears, and most details of how it moves. The tag has proved such a sensitive tool for studying behavior and for monitoring responses of marine mammals to manmade noise, that it has revolutionized the study of behavioral disruption.
Originally published: August 7, 2003