World's Largest Animal Migration Every Night!

World's Largest Animal Migration Every Night!

Marine biologist and filmmaker Rick Rosenthal is the first to dive into and record the largest migration on Earth.

The "vertical migration" is the movement each evening of billions of ocean animals — teeming swarms of fish, squid, krill, jellyfish, tiny copepods and more — that swim upward more than half a kilometre from the deep to feed on plankton near the ocean surface in the darkness. Before sunrise, they swim back down to the relative safety of the depths. On his film Ocean Magic at Night  Rosenthal talks about the challenges and rewards of filming the amazing phenomenon.

The vertical migration is an important part of the ocean food chain. Larger predator animals will eat at night when food like squid and lantern fish come to the surface where they are. That way, they don't have to dive so deep. 

"We didn't really know very much about the vertical migration until the military started studying it in the mid-20th century. It's so thick that they would hide submarines under it. In some places, the vertical migration is so thick that it even changes the direction of ocean currents.

The technology is now there to allow us to film the migration. Digital cameras let you record at night with very little light. So you see incredible things with very little lighting. You don't want to use too many lights down there because you would be changing the behaviour of the animals you went to see," he says. To see more fantastic footage and learn more about this incredible migration click here: