On November 14, 2016, the magnitude 7.8 Kaikoura earthquake struck New Zealand’s South Island, causing a destructive tsunami, as well as two deaths and a few dozen injuries. Under the surface, the seismic event spawned strong currents that swept away and mostly killed off diverse ecosystems of invertebrates living along the Kaikoura underwater canyon. The massive landslide not only clouded the water, it flushed the animals hundreds of miles away, likely rearranging the makeup of the entire ecosystem.

As a result, sperm whales had to dive deeper and longer to find food—a “major shift” in their behavior, says co-author Liz Slooten, a marine biologist at the University of Otago in New Zealand.

Slooten was studying sperm whales in