Friday, May 21, 2010

Oceanic White Tip Sharks: curious pelagic predators with an unfair reputation

A sleek but muscular body gliding effortlessly through cobalt blue water, its rounded snow-capped dorsal fin slicing the water just below the surface, the Oceanic White Tip Shark is one of the premier pelagic (open ocean) predators.

Beqa Adventure Divers's blog picked up on a series of terrific photos of oceanic white tips, posted by LupoDiver on a recent South Atlantic trip with Jim Abernethy's Scuba Adventures.

Oceanic white tip sharks are important open ocean predators and scavengers. As with most other sharks, they play a critical role in keeping the oceanic backyard clean and the populations of their prey healthy by culling the weak, injured, and sick. They are intensely curious as they do not live in a world of wall-to-wall animals, so anything that catches their attention either visually or by scent is quickly investigated.

Unfortunately, these sharks also have a bad reputation carried down through history as a man-eater. Often attracted by the low frequency sounds given off by sinking ships (not your typical underwater background noise), particularly from sinking warships, these sharks were known to attack sailors in the water - their hunting/scavenging instincts piqued by blood from wounded sailors. Sadly, what began as natural curiosity and a reaction to food stimulus in a limited-prey environment turned into a fearsome oceanic killer reputation. Turn down the anxiety level a few notches and you get a lot closer to the truth, as LupoDiver and his fellow divers discovered on their trip.

Beqa Adventure Diver also comments on LupoDiver's picture of a blue shark, another pelagic predator whose numbers have dropped considerably over the years, a favorite target for the commercial shark fisheries.

My first unexpected encounter with a shark in open water was with a beautiful blue shark, over 20 years ago, off Santa Cruz Island which is part of California's Channel Island chain. Following that, my first cage diving experience was being surrounded by a group of blue sharks. Now, Southern California's blue shark diving operations have all but disappeared and, sadly, I suspect I may never come across another blue shark without a lot of chumming and patience.

LupoDiver, treasure your experience with the oceanic white tip and blue shark. Like the great white shark and others, these are very unique and important members of a healthy marine ecosystem. Without them, both the oceans and mankind are the lesser for it.

1 comment:

DaShark said...

Thanks for the hat tip Richard!

You're right, those are terrific pics - as are the Sharks!
Check out for a possible explanation of the white tips - fascinating stuff!