Bottom Line: This eye-opening shark-umentary packs considerable bite

By Michael Rechtshaffen

Looking to reclaim some of the integrity snatched away by Mr. Benchley and Mr. Spielberg, “Sharkwater” is both a startlingly photographed portrait of that maligned denizen of the deep and a chronicle of filmmaker Rob Stewart’s efforts to curb rampant shark poaching in Costa Rica and the Galapagos Islands.

While those twin intentions don’t always merge swimmingly, Stewart’s documentary is seldom less than compelling in its quest to raise international awareness about a situation that is threatening to put sharks on the endangered list.

The Canadian production, which had the largest opening of any indigenous docu when it opened north of the border in March, should attract some “An Inconvenient Truth”-style attention when it opens Nov. 2 in 20 U.S. markets on the heels of a regional Florida release last month.

Stewart, an award-winning photographer who has been swimming with the sharks since he was a child, initially sets out to show the heavily sensationalized creatures through his eyes, intermingling the vibrantly breathtaking HD footage with archival snippets of old black-and-white shark attack instructional films.

Myths are debunked in the process, with narrator Stewart noting that in 2005, human encounters with the mighty predator led to just five fatalities worldwide, a fraction of the deaths caused each year by tigers and charging elephants.

But what starts off as something of a marine version of “Grizzly Man” soon changes course when Stewart hooks up with renegade conservationist and Greenpeace co-founder Paul Watson.

It turns out that China’s appetite for shark fins — specifically for soups and medicinal purposes — has created a multibillion-dollar shark-finning industry, and though some countries have banned the practice, illegal long-line fishing has contributed to the slaughter of 100 million sharks a year.

A trek taken by Watson and Stewart to Cocos Island off Costa Rica uncovers the presence of dozens of clandestine shark fin-drying operations overseen by the Taiwanese mafia, contributing to the serious depletion of the world’s shark populations.

In between all the environmental derring-do, ducking both pirates and police, Stewart finds himself sidelined with a life-threatening flesh-eating virus, but it isn’t long before he again takes up the cause.

With all that stirring underwater photographer and a buoyant, propulsive score by Jeff Rona — complemented by song selections from Nina Simone, Portishead and, appropriately, Moby — it’s hard to resist climbing aboard.