Mr. Sustainable Seafood — you know, Barton Seaver, chef at Blue Ridge and your favorite punching bag — is serving up a multi-course dinner on Friday to accompany a screening of Rupert Murray’s documentary, The End of the Line .  Seaver’s main course? A preparation of red lionfish.

Never heard of red lionfish?

It’s not exactly common on local menus, although Seaver sort of wishes it were. Snacking on red lionfish might help the coral ecosystems along the southern Atlantic coast, where the invasive species (with no known predator) has been wreaking havoc with fish and humans alike.  In fact, Seaver would love to see local menus featuring an Invasive Species Bouillabaisse with red lionfish and northern snakeheads in a zebra mussel broth with kudzu.

He’s joking, but just.

Anyway, back to the subject at hand: Seaver’s dinner and the screening of The End of the Line. The documentary, based on British journalist Charles Clover‘s book of the same name, is all about the effects of overfishing. Invasive species and overfishing are two different subjects, yes, but they both have huge impacts on the health of underwater ecosystems.

And both problems are man-made. Consider the red lionfish. Seaver says that a collector in Miami accidentally released six — yes, six — lionfish when a hurricane (possibly Andrew, he couldn’t remember for sure) destroyed his home aquarium. Now the heavy breeders are all over southern coastal reefs, gobbling up small fish and endangering human divers with their venomous spines.

Seaver will talk more about the fish, I’m sure, during Friday’s dinner at Blue Ridge. (As Clover will talk about overfishing, his Fish2Fork restaurant guide, and The End of the Line, which hits the DVD market next month.)  Unfortunately for you, the $75 dinner and a movie is sold out.

Which is just as well. It seems Seaver is having trouble securing lionfish for the dinner.  His first supplier “didn’t come through,” but he swears he’ll have some by Friday.

In the meantime, if you want to take part in the sustainable seafood movement, Seaver suggests you start a dialogue with your favorite restaurant or your fish monger. Find out what fish and shellfish are sustainable.

“There are a lot of choices we can make that are delicious,” Seaver says. “It’s not all about sacrifice.”