DTAG data plot showing whale could dive deeper after disentanglement

Red and blue lines describe the depths of a whale’s dives in work by WHOI-MIT Joint Program graduate student Julie van der Hoop and biologist Michael Moore, director of the WHOI Marine Mammal Center. The two analyzed data from a DTAG to track dives made by a female North Atlantic right whale called EG3911 that was entangled in fishing gear. Working with colleagues from NOAA and other institutions they sedated the whale so that rescuers could remove the gear trailing behind her. The team found that, when freed, she dove nearly twice as deep (red) as previously (blue), illustrating the effort it takes whales to swim when entangled. (Illustration courtesy of Julie van der Hoop et al., © Woods Hole Oceanographic Institution)