TRIBECA, brief chat with Mark Grieco of “A River Below”

The footage is muddy, but we see it clearly enough: a pink dolphin—one of many endangered species populating the Brazilian Amazon—is harpooned to death by a group of fishermen, to be used as bait for the pirapitinga, a breed of scavenger catfish. This is just the beginning of Mark Grieco’s wrenching documentary “The River Below,” currently showing at Tribeca. Filmed over two difficult years, it crafts an unsettling parable about the ever-widening rift between environmental and business interests.

Grieco neither lionizes, nor excoriates, any of the central figures: Fernando Trujillo, a longtime conservationist devoted to outlawing pink dolphin hunting; Richard Rasmussen, a boastful animal TV show host whose insidious recording of the slaughter led to a ban on pirapitinga fishing in Brazil (beyond the unethical baiting practices, this fish, exported regularly to Colombia, is contaminated with mercury); and the impoverished fishermen themselves, whose community’s sole source of income is the pirapitinga. Though he loudly proclaims to be, Rasmussen is certainly not a hero. He lied to the fishermen, assuring the shoot would not be shown to a large audience and that he’d help them find an alternate bait. As a result, some of them are even threatened with violence by vendors. But then again, without Rasmussen’s efforts, the nation would not have responded so promptly to an undeniable problem. Meanwhile, Trujillo’s exhaustive research on dolphin killing has been largely ignored, and the film slyly poses the troubling question as to why people need such a brutal exposé to take action.

In a further note of bitter irony, Grieco himself had to mislead Rasmussen about his exact purpose to yield the fascinating climactic sitdown between Rasmussen and the fishermen, a fact that Rasmussen—in the film’s most harrowing scenes—furiously takes Grieco to task for. This is a film bold enough to risk depicting its own makers in a negative light.

“We didn’t even have Richard as part of the film until we found the fishing villagers, and they told us that this Brazilian TV star came and filmed them,” said Grieco in an interview with Screen Comment Sunday. “When we first approached him, we didn’t tell him that we had been to that town. His mission made him a complex character to us. I had to continue to try to humanize him.”

“This film is questioning what it takes to get a story,” Grieco continued. “Should we just accept what we see, and not ask what it takes to be able to film something like that? And what you find is typically very troubling.” (Another excellent Tribeca film, Reuben Atlas’s “ACORN and the Firestorm,” about the infamous hidden camera subterfuge of the now-defunct political activism group ACORN, also challenges audiences’ tendencies to take sensational media footage at face value).

“I asked myself what is it that I have to do to get this story. In some ways, it’s an indictment of me as a filmmaker. But that was the only way I felt I could get to the heart of Richard, to break through this performance he was doing for us.”

Not setting out with a cut-and-dry story in mind is a tactic that has worked for Grieco. “The best thing I learned from my last film is that you start with a very simple idea, and if you’re paying attention, the story that really wants to be told is whispering, not screaming.”

“I didn’t want to make the typical ‘Save the Dolphin’ film,” said Grieco. “I wanted to make a cinematic film, a character-driven film, an exploration of morality and ethics. I wanted to leave the audience questioning itself.”

Filmmaker Mark Grieco

Filmmaker Mark Grieco

The following screenings remain :