I’d had company since I first dived into the inky water. Just on the edge of my visibility a pair of Oceanic Whitetip Sharks, Carcharhinus longimanus, had followed my every move. Famed oceanographer, Jacques Cousteau described them as "the most dangerous of all sharks" and his words echoed in my mind.
All I could see of them was the silvery tips of their huge pectoral fins. Growing to four metres and 170 kg and considered to be responsible for most open ocean shark attacks, these elegant fish are nature’s ultimate predator and were my biggest worry.
That was 30 years ago and Oceanic Whitetips were always around me. The
last time I dived the outer Barrier I was alone. In 1969, Lineaweaver and
Backus wrote of the Oceanic Whitetip: "[it is] extraordinarily abundant,
perhaps the most abundant large animal, large being over 100 pounds
[45 kg], on the face of the earth". Now overfishing has brought about a catastrophic
collapse in their numbers. The International Union for the Conservation of Nature lists them as
“Critically Endangered” in the Northwest and
Atlantic and “Vulnerable” globally.