Fishermen release bait fish during pole and line fishing practice to catch skipjack tuna. Pole and line fishing is a selective and therefore more sustainable way to catch tuna as only fish of a certain size are caught, leaving juveniles to grow to spawning age and replenish the stock in the future. Small bait fish are thrown over the side of the boat to lure the tuna to the water surface. The fishermen use the acceleration of the fish as they race to get their prey, hook them and fling them onto the ship's flat deck.