22 May 2013:
Whale’s Battle with Nets
Is Revealed Through Monitoring Device
A small monitoring tag attached to an entangled North Atlantic right whale revealed just how much fishing gear impairs a whale’s ability to swim, dive, and feed
, scientists say. After locating a two-year-old whale, dubbed Eg 3911, with fishing gear entangled around her mouth and pectoral fins, a team of
scientists was able to attach a so-called Dtag in January 2011 that recorded her movements before, during, and after the team removed the nets. The whale “altered its behavior immediately following the disentanglement,” according to the study published in the journal Marine Mammal Science
. She swam faster, dove twice as deep, and stayed underwater for longer periods. Scientists say the added buoyancy, increased drag and reduced speed caused by such gear may overwhelm an animal's ability to forage for preferred prey, delay its arrival to feeding or breeding grounds, and ultimately drain its energy. Indeed, two weeks after disentangling Eg 3911 from the nets, an aerial survey spotted her dead at sea. A necropsy found the effects of chronic entanglement caused her death. Entanglement with fishing gear
is the leading cause of detected deaths of large whales in the Northwest Atlantic, scientists say. Only 450 to 500 North Atlantic right whales remain alive today.