When you’re a veteran director who’s never made a fake documentary or a work of true science fiction or an ecological screed, I imagine there’s still a way to make a single movie of all three, a movie that scares, informs, and entertains, a movie that makes you bite your knuckles while robo-dialing your senator. That’s the movie “The Bay” would like to be: a righteous freak-out. The movie recalls incidents in which tons of fish have washed up dead on the shores of the Chesapeake Bay (in 1976 the death toll was about 15 million). The cause was severely cold water and algae bloom. Barry Levinson imagines the worst-case pollution scenario and coughs up a flesh-eating parasite in “The Bay.”

A young reporter named Donna Thompson (Kether Donohue) sits in front of a laptop camera and talks to unseen men about the footage she’s assembled from one particularly disgusting July Fourth in 2009. She was a broadcast intern covering the local parade when a woman with blistering skin disrupts the festivities to beg for help. The crowds scatter, but soon a lot of the 6,200 residents of a small Maryland town have moist pustules, mysterious growths, and missing tongues. Some of those people are dropping dead; some are eating themselves. The Centers for Disease Control and the Federal Emergency Management Agency prove uselessly bureaucratic, though maybe they know that some of this has to do with a faulty desalinization system and the tons of fowl fecal matter being dumped into the bay. Throughout, Donna remains cluelessly on the case.