Whales dine with their friends of the same species
For a few weeks in early fall, Georges Bank — a vast North Atlantic fishery off the coast of Cape Cod — teems with billions of herring that take over the region to spawn. The seasonal arrival of the herring also attracts predators to the shallow banks, including many species of whales.
Now researchers from MIT, Northeastern University, the Institute of Marine Research in Norway, and the National Oceanic and Atmospheric Administration, have found that as multiple species of whales feast on herring, they tend to stick with their own kind, establishing species-specific feeding centers along the 150-mile length of Georges Bank. The team’s results are published today in the journal Nature.
Based on acoustic data they collected in the region in 2006, the researchers identified and mapped the calls of various whales, and discovered a clear grouping of species within the dense herring shoals: Humpback whales congregated in two main clusters, at either end of the spawning grounds, while minke, fin, and blue whales set up feeding territories in the space in between.
In general, calls from each whale species increased dramatically at nighttime, when herring tended to form extremely dense shoals. During the day, these whale calls dissipated, as herring scattered throughout the seafloor.
These results represent the first time that scientists have observed such predator and prey interactions over a large marine region.
Whales image via Shutterstock.
Read more at MIT News.