Endangered fish found swimming in Charles River, named Henry

It emerged from the depths of the Charles River, about three feet long and covered in armor.

“First of all, it was unbelievably cool,” said Executive Director of the Charles River Watershed Association Bob Zimmerman, referring to the Atlantic sturgeon  a local accountant spotted swimming close to the river’s surface last week.

The fish, a member of an ancient and endangered species, is the first Atlantic sturgeon to have been found in the river in years, he said. The brief sighting of the sturgeon has raised area scientists’ hopes about the future of the historically polluted river.

“I’ve been here [at the CRWA] for 21 years and I’m unaware of anyone seeing a sturgeon in the Charles River in living memory,” he said, adding that he had nicknamed the fish “Henry.”

Though sturgeon were plentiful in Colonial times, used by early Massachusetts settlers for food and caviar, they are currently so rare that in most parts of the state they are classified as endangered.

The sighting was “one of those remarkable events that we have no explanation for so far,” Zimmerman said.

The man who found the fish, Rick Bellitti of Charlestown, was walking along a bridge near the Charles River harbor when he spotted the fish swimming in the water just below him, Ayer said.

Since he did not recognize the species, he snapped two photos with his phone and later emailed them to the New England Aquarium for identification.

Zimmerman said scientists easily identified Henry as an Atlantic sturgeon because of his pointed snout and armor plates.

“That’s a very telltale fish,” he said.

Atlantic sturgeons, which can be about three to five feet long and weigh up to 800 pounds, have “been around for potentially millions of years,” said Matt Ayer, an aquatic biologist at the state’s Division of Marine Fisheries.

He added that this sturgeon in particular, not a sexually mature adult, might have been foraging for food.

There is almost no way to tell exactly where the fish came from or where it was going, he said.

He said its presence, though inspiring to many scientists, might not be indicative of any larger sturgeon-related trends.

Henry may have appeared in the river “potentially because of the cleaner environment in the Charles and the harbor in general,” Ayer said.

In the 1960s, untreated sewage and “toxic discharges from industrial facilities” spilled into the river. Also, “fish kills, submerged cars and appliances, leaching riverbank landfills and noxious odors were routine occurrences,” according to the CRWA website.

Since then, national and state legislature, including the Clean Water Act of 1972, combined with the efforts of volunteers and organizations such as the CRWA have worked to clean the river.

Now the river is swimmable in “dry weather” and populated with more than 20 species of fish, according to the CRWA.

Zimmer said seeing pictures of the sturgeon was reinvigorating and “very hopeful.”

Still, he said, “we’ve got a long way to go.”