Most sharks are predators which eat smaller fish, and are at the top of their food chains, so that their numbers are limited anyway. Their role is to maintain the "genetic fitness" of their prey species, thus conserving ecological quality and balance.
大部分的鯊魚屬於掠捕食性，大魚吃小魚，是食物鍊中最高層的生物，因此數量原本就少，它扮演提昇其他動物基因品質的功能，如此才得以維持生態品質與平衡。