Shot over a ten-month span, Coral Reef Adventure spotlights some of the most beautiful and remarkable oceanic organisms. Filming in Australia, Fiji and French Polynesia, director Greg MacGillivray tries to show how fragile the coral reefs and their environment are. More than most large-format documentaries, the film spends a considerable amount of time on ecological issues. Sadly, Coral Reef Adventure offers at best guarded optimism about the future of its subject.

Opening in Fiji, the film follows native diver Rusi Vulakoro as he examines a stretch of coral reef that has mysteriously died. Alarmed, he alerts Howard Hall, an expert diver and underwater photographer. When he sees the damage that has been done, Hall sets out with his wife Michele to survey the health of reefs throughout the South Pacific.

Their first stop is Australia's Great Barrier Reef, an enormous, living organism teeming with life, from bulldozer shrimp to venomous snakes. Oceanographer Tracey Medway shows Hall an enormous potato cod with living toothbrushes--tiny Cleaner Wrasse fish that scrub its teeth of parasites.

The dead reefs in Fiji are a stark contrast. The Halls discover that they are threatened by global warming, by overfishing, and by lumbering and agriculture that result in excess silt and sediment. Aerial photography shows just how devastating the muddy runoff can be.

Hall joins scientist Richard Pyle in dives to depths over 350 feet to photograph ghostly whip and fan corals. The immense water pressure causes one camera to fail. During another dive, Hall comes down with the bends, a potentially fatal condition. Production is halted for weeks while he recovers.

The Halls also visit French Polynesia, the site of volcanic atolls surrounded by reefs. Near the Rangiroa atoll, they search for the elusive and deadly grey shark. Here the film's ecological message is supplanted by adventure footage better suited to sweeps week on cable TV.

In fact, Coral Reef Adventure often seems torn between genuinely educational scenes and material that is merely exploitative. The pop soundtrack of Crosby, Stills and Nash songs, augmented by intrusive sound effects, further blurs the film's serious intent. But Coral Reef Adventure can be enjoyed simply as a spectacular South Seas travelogue with superb underwater footage. Its environmental warnings are an added and important bonus.

--Daniel Eagan