Killer whales (Orcinus orca L.) and saithe (Pollachius virens L.) trap herring (Clupea harengus L.) in shallow water by taking advantage of steep bottom topography
Original version
This report is not to be cited without prior reference to the authorAbstract
Whales and fish use a wide range of hunting tactics in order to catch their prey. Predatorprey
interactions have been seen during the massive wintering of herring (Clupea
harengus) in steep bottomed topography in Lofoten, northwestern Norway. We applied
hydro-acoustics to document how killer whales (Orcinus orca) and Atlantic saithe
(Pollachius virens) herd and trap herring in shallow waters before attacking their prey. A
group of eight killer whales and a shoal consisting of hundreds of saithe concentrated
their attack on the side of the herring schools that faced away from the shallow area.
They thus effectively herded the herring towards the shallower water. The predators then
surrounded the schools, preventing the herring from escaping to deeper, darker and safer
water. Some predators attacked herring by penetrating the school, while others continued
surrounding the school. These are the first, well-documented hydro-acoustic observations
of this hunting tactic. Further research will reveal if this hunting tactic is common and
widespread among other species of marine mammals and fish preying on fish schools in
coastal waters.