Brian Skerry at the New England Aquarium

Fisheries are dwindling. The acidity of the ocean is getting worse. Pollution and dangerous bacteria levels are on the rise. (And, of course, there are pirates.)

The sea is in trouble. It may not always look like it from the surface, but down in the dark and chilly depths, it’s more threatened today than at anytime in world history.

Uxbridge native Brian Skerry has been an underwater photojournalist since he was 15, and has been contributing to National Geographic for more than a decade. Over the years, his travels have taken him from the Bahamas to Trinidad and Tobago to the waters off Scotland, where he’s submerged beneath the brine to swim alongside sharks and point his camera at schools of giant squid.

Skerry doesn’t like seeing his workplace in trouble. So tonight, at the New England Aquarium (where he’s also an overseer), he’ll be giving a talk, “Crucial Waters: Reporting On The World's Oceans,” where he’ll show off some of his stunning photographs as he tries to sound the alarm about ocean degradation and overfishing.

It starts at 7 p.m. and is free and open to the public. Register and get more information here.