Minnow Migration 02 Time Lapse

The USS Spiegel Grove is located 5 sea miles east of Key Largo. The former dock landing ship was intentionally sunk in 2002 and lays 135 foot deep. Each summer large schools of minnows migrate to this ship wreck but their migratory behavior is not fully understood yet. Therefore I hope that my documentation shines some new light into this fascinating annual spectacle. The first schools arrive in early July and settle into the upper deck of the wreck. Soon more and more minnows swarm in from all directions. Minnow is a general term for these tinny, silver fish in particular those used as bait fish.
And bait fish is what the Jacks are after, which have followed the minnows to the wreck and soon their feeding frenzy begins. The Jacks attack in group vigorously, trying to single out individual fish for easy pickings. The minnows try to escape the attacks by hiding in the many rooms on the upper deck. Only to discover that some of its permanent residents do not tolerate their intrusion. And to make matters worse, the continuously growing numbers of minnows have occupied all available spaces on the upper deck by now.
So the silverlings seek protection from their predators by escaping into the lower deck, which is darker and less favorable but still a valuable alternative. Here they continue to assemble, building up into larger bait balls. But the predators learn quick and follow the minnows into the darker spaces too. Now the best chances of survival lays in numbers and by late August the wreck seem to overflow with millions of these tinny fish.
Finally the many bait balls will join each other and grow into giant formation, moving through the water like some bizarre alien from a different planet. Divers from all over the world arrive each year in Key Largo to witness this amazing natural phenomenon one hundred feet below the surface.
By mid September the 510 foot long wreck seems to be engulf by countless schools of minnows and the large numbers of Jacks which continuously attacking and feeding on such plentiful prey. The minnow migration of Key Largo was filmed by Heiko Kiera aka Ojatro in 2015.