Unmistakable in the water: a stocky gray-bronze shark of about 3 m (10 ft) with enormously long, rounded, white-tipped pectoral and dorsal fins that it holds out like wings. It cruises slowly at the surface in open water, usually with pilot fish riding the bow wave ahead of its snout, and it comes to look at anything new.
Those fins are a fuel strategy. Open ocean is a desert with widely spaced meals, and a shark that finds food by covering distance cheaply outlasts one that swims fast. The long planing surfaces let this animal hang in the water at almost no cost and turn on a meal when one appears, and the same design makes it slow, deliberate and impossible to shake once it has decided to follow something.
It used to be, by some estimates, the most abundant large animal on the planet above about 45 kg (100 lb). Longline and purse-seine fisheries removed something like 98 percent of it in the space of a few decades, which is among the steepest recorded collapses of any large vertebrate, and it is now Critically Endangered.
Which makes the offshore reefs here globally important out of proportion to their size. The Brothers and Elphinstone are among the last places on Earth where the species can be seen reliably from the water, in season, by anyone; researchers come here specifically because the animals are countable. The reputation for danger is not invented - this is the shark associated with open-water disasters, and it will press a diver - but the encounters that happen here are almost all at a distance, and a shark that circles closer needs to be watched, not fled.
The species. Carcharhinus longimanus (Poey 1861) - longus (L.). ETYFish
- very long rounded pectoral and dorsal fins, tipped and mottled white
- stocky gray-bronze body, blunt snout
- usually accompanied by pilot fish at the snout
- cruises slowly in open water near the surface
