The fishermen — and fish — were out in Edgardown’s inner harbor Sunday. But there were no striped bass or bonito on the hooks. Instead, they were casting for menhaden.

The small, oily, inedible fish are prized bait, especially for striped bass. This time of year, when derby fishermen are vying for the largest striped bass, a premium is placed on menhaden.

Anglers will pay top dollar for quality bait.

Menhaden are not your usual fish. Since they feed on plankton, no lure will get their attention. To catch them, fishermen must cast weighted treble hooks into schools and reel in the lines quickly. The fishermen hope to snag the fish with a hook. But it’s not easy.

On Sunday two fishermen moved about the harbor in a small powerboat mostly drifting and hunting for menhanden schools. They’d cast their hooks and yank hard on their light tackle. As is often the case, only occasionally was the effort fruitful.