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Rare Fish in Saco River Makes Scientific Splash

June 24, 2009 - BIDDEFGORD -- A team of University of New England researchers that is studying the reappearance of Atlantic sturgeon in the Saco River came up with an even more surprising find this week: a shortnose sturgeon.

While the Atlantic sturgeon had seemingly disappeared for about 100 years, its more rare cousin had apparently never been seen in the Saco. At least not until researchers pulled one up Tuesday.

"It's crazy," said James Sulikowski, assistant professor of marine sciences. "Nobody had any idea that we would catch a shortnose."

Both types of sturgeon are prehistoric-looking, bottom-dwelling fish that are covered with bony scales and plates.

"They have remained relatively unchanged for maybe 40 million years," said Tom Squiers, fish restoration director with the Maine Department of Marine Resources.

Both Atlantic and shortnose sturgeon spawn in fresh water and live in salt water. Both were more common along the Maine coast a century ago, before fishing pressure, pollution and dams reduced their numbers. They were valued for their meat and eggs – caviar.

Atlantic sturgeon grow to 14 feet and migrate up and down the coast. Fishing for them is now banned, and federal officials may soon declare them threatened or endangered.

Shortnose sturgeon, which are already an endangered species, grow to only 4 or 5 feet and tend to stay in or near their native rivers.

Sulikowski and his students have been studying Atlantic sturgeon in the Saco River since catching one during a research expedition in 2007. Scientists had not found the fish there for about a century before that and "had written the Saco off, basically," Sulikowski said.

In the past two years, the UNE team has caught more Atlantic sturgeon and even seen some jumping out of the water near the mouth of the river. The researchers suspend nets near the bottom of the river next to the jetties and release the fish unharmed.

Based on its find, UNE got a $50,000 federal grant to expand its study this year. On Friday, Sulikowski and his students released an Atlantic sturgeon carrying an acoustic transmitter in its belly. The transmitter works like an E-ZPass and will send a signal to a receiver every time the fish swims in and out of the Saco.

"Hopefully, within the next two to three weeks, we'll have 25 sturgeon with acoustic tags in them," Sulikowski said.

The researchers hope to figure out whether the fish are visiting the Saco or returning there to spawn.

"So as far as we know, those sturgeon are from the Saco River," he said. "If the Saco is providing a consistent habitat for sturgeon, then what it will mean is it's a river system that is sort of imperative to the survival of the species."

In either case, it's a sign of a fish population recovering thanks to cleaner water and fishing restrictions, scientists said.

On Tuesday, Sulikowski and students were working on that research project when they caught the shortnose sturgeon.

Word of that catch spread quickly to federal scientists and others.

Squiers, for one, thinks it may be another sign that the state's only known spawning population of shortnose sturgeon – in the Kennebec and Androscoggin rivers – is expanding. He and others believe one of those fish paid a visit to the Saco.

"Shortnose sturgeon were thought to stay within their natal river system," he said. "It appears, based on the work in Maine, that they're moving more than thought."

The presence of an endangered species can affect human activities. Some development in established habitat areas, for example, can be subject to an additional layer of federal review.

Sulikowski, however, said he doesn't expect any downsides.

"We were just excited about having Atlantic sturgeon in the area and learning more about them, but now with the shortnose ... all of it's really new for us," he said. "It's a positive for the ecosystem and for everybody around there."

JOHN RICHARDSON, Portland Press Herald, June 20, 2009


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