The Great Fish Migration

The secret lives of fish are coming to light
A tarpon turns into a column of mullet as they make their fall run south past Jupiter Inlet. Photo by Paul Dabill Photography

In September, the beach is warm and inviting, but you may find the water a bit crowded this time of year. A river of mullet is just offshore, cruising south with speed after a summer of feeding and breeding. From the beach, the water looks alive, churning and erupting with fountains of mullet leaping to avoid their hungry pursuers. You may find the shore more crowded, too, with fishermen angling to take advantage of the bounty that follows the annual “Mullet Run.”

Their tails flick make a swirling motion that gives the trailing mullet momentum as they draft in behind. Hot on their heels are larger fish looking to fatten up on the plump males and roe-filled females, which are rich in omega 3. Hunting for food in cold water will be more taxing, so predators are looking to increase their fat stores now. Much like on the African plain, where large predators follow wildebeests for a hundred miles or more and stalk them from hiding places, fish higher up on the food chain will chase the mullet for long distances, or just lie in wait under piers and strike when they swim past.

Mullet are forage fish, which feed on algae and phytoplankton, so during fall migration they swim open-mouthed as they stay very close to wave energy at the shore and filter food through their gill rakers as they run. Mullet are a very ancient species; they survived the extinction of dinosaurs, but their numbers dipped significantly when they were scooped up in gill nets by the millions when their roe was prized in Korea and Japan. The gill net ban in 2003 was a key contributor to restoring their robust populations.

Categories: Features