Free School Tuna Set

A free-school set is a tropical-tuna purse-seine set made on a naturally occurring, free-swimming school rather than on a fish aggregating device. Skippers locate free schools by spotting bird flocks, surface boils, or sonar, then encircle them with the seine. Free-school sets take a larger proportion of adult yellowfin and skipjack and produce far less bycatch of juvenile bigeye, silky sharks, and turtles than drifting-FAD sets, so the tuna RFMOs encourage them through FAD limits, FAD closures, and bycatch caps. Because they need active, visible schools, free-school sets are less reliable per search day than FAD sets.