Oceanographers produce first-ever images of entire cod shoals
For the most part, the mature Atlantic cod is a solitary creature that spends most of its time far below the ocean’s surface, grazing on bony fish, squid, crab, shrimp, and lobster — unless it’s spawning season, when the fish flock to each other by the millions, forming enormous shoals that resemble frenzied, teeming islands in the sea. These massive spawning shoals may give clues to the health of the entire cod population — an essential indicator for tracking the species’ recovery, particularly in regions such as New England and Canada, where cod has been severely depleted by decades of overfishing. But the ocean is a murky place, and fish are highly mobile by nature, making them difficult to map and count. Now a team of oceanographers at MIT has journeyed to Norway — one of the last remaining regions of the world where cod still thrive — and used a synoptic...