Sound reveals giant blue whales dance with the wind to find food
Published:18 Oct.2022 Source:ScienceDaily
Tracking blue whales by their booming vocalizations, researchers have revealed how these ocean giants find dense aggregations of food.
This study built upon previous research led by MBARI Senior Scientist Kelly Benoit-Bird, which revealed that swarms of forage species -- anchovies and krill -- reacted to coastal upwelling. This time, researchers combined satellite and mooring data of upwelling conditions and echosounder data on krill aggregations with the acoustic tracks of foraging blue whales logged by the directional hydrophone.Previous work by the MBARI team found that when coastal upwelling was strongest, anchovies and krill formed dense swarms within upwelling plumes. Now, we've learned that blue whales track these dynamic plumes, where abundant food resources are available.
Blue whales recognize when the wind is changing their habitat and identify places where upwelling aggregates their essential food -- krill. For a massive animal weighing up to 150 tonnes (165 tons), finding these dense aggregations is a matter of survival.While scientists have long recognized that blue whales seasonally occupy Monterey Bay during the upwelling season, this research has revealed that the whales closely track the upwelling process on a very fine scale of both space (kilometers) and time (days to weeks).