It’s reasonable to wonder why the big blue catfish flood the Santee Cooper shallows from late-March through April. The answer is simple, but it’s not the spawn — as many think.

Biologist Scott Lamprecht said the water temperatures this time of year are not conducive to catfish spawning.

“This move to the shallows is all about food,” he said. “It’s usually late spring, probably May and June, when the majority of our catfish spawn. The key for this shallow-water surge is prompted by a typical catfish response: they’re following forage. Specifically, big catfish target the ocean-run herring that begin to flood into the lakes during March and April. As the water warms, many other species of fish get into the shallows, and they also become potential forage for catfish.”

Lamprecht said herring orient to shallow vegetation in both lakes, and catfish follow them. When cats move into the shallows to spawn, fishing success typically decreases.

“I get calls every year from catfish anglers worried that all the big blue catfish are gone,” he said. “What actually occurs in May and June when water temperatures warm significantly is catfish start spawning, and during that process, making more catfish is the priority, and feeding activity slows.”

Lamprecht said not all catfish spawn at the same time, but over a relatively short period of time during late spring. Fishermen will note a drop off in catfish activity.