Oceanic Whitetip Shark

It has the temperament to be, and a poor reputation, but very few people ever encounter one because it lives far out in the open ocean rather than near beaches. Where it does meet humans, typically shipwreck and ditching survivors, divers on remote blue-water sites, or people spearfishing offshore, it is bold, persistent, and slow to be deterred, circling and bumping and returning after being pushed away, behaviour that makes sense for an animal used to investigating any potential food in a food-poor environment. Historically it is blamed for many deaths in open-water disasters, and it remains a shark to treat with respect at sea, but attacks on ordinary swimmers are essentially unknown simply because their paths do not cross.

That description comes from mid-twentieth-century marine biologists, notably the shark researcher who wrote that the oceanic whitetip might be the most abundant large animal, larger than a few metres, on the planet. Whether it literally outnumbered every large mammal and other fish is impossible to confirm, but the claim reflects a real situation. Across the enormous area of the tropical open ocean, the oceanic whitetip was the default large predator, present almost everywhere warm water met the surface, and fishing logs and sailors' accounts from that era describe them as constant companions. That baseline is what makes the modern decline so stark.

Two reasons. First, it lives exactly where the world's industrial tuna longline fleets operate, in the tropical open ocean, so a huge fraction of the population is exposed to hooks set for tuna and swordfish, and oceanic whitetips are caught as bycatch by the millions. Second, its fins are large, distinctive, and prized in the shark-fin trade, so for decades the sharks that were caught were routinely finned rather than released. A slow-breeding animal being removed at that rate over its entire global range had no refuge, and its numbers collapsed within a few decades from abundant to critically endangered.

They are unrelated despite the shared name. The whitetip reef shark is a small, slender, bottom-associated shark, usually under 1.6 m, that rests in caves on coral reefs by day and has narrow, pointed, white-tipped dorsal and tail fins. The oceanic whitetip is a large, heavy-bodied shark of the open sea with hugely long, broad, paddle-like pectoral fins and a big rounded first dorsal fin, all mottled white at the tips, and it never rests on the bottom. If it is a stocky shark far from land with rounded, white-splotched fins, it is an oceanic whitetip; a slim shark tucked under a reef ledge is the reef species.