It was by far the nastiest-looking catch of the day. 

Field technicians with Fort Folly Habitat Recovery were surprised to discover a 75-centimetre sea lamprey in one of their salmon counting fences in the Petitcodiac watershed on Monday.

Laura Buck and a co-worker were going through their catch box when they saw what they thought was a piece of wood at the bottom -- until it moved. 

"They're a pretty nasty looking fish," Buck said. 

Sea lampreys have a suction-like mouth with rows of circular teeth and six to seven holes on each side of their bodies.

"We might have squealed a couple of times and were a little grossed out," Buck said.

Common to the area

Sea lamprey

Sea lampreys are commonly found in the Pollett River. (Fort Folly Habitat Recovery)

This is the biggest sea lamprey they've caught in the Little River, which is connected to the Petitcodiac watershed. But it's not the first.

"Not a lot of people know that the species exist or that it's even in our river system here in New Brunswick," Buck said.

Sea lampreys are often mistaken for eels because they have a similar body shape. The species is common to the Petitcodiac watershed. 

"We've caught them in all parts of the watershed, especially the Pollett River," she said. 

Sea lampreys are an anadromous fish born in freshwater. They spend most of their lives growing out in the sea, before returning to fresh water to spawn and live out the rest of their lives.

"They are definitely an interesting species, so it's kind of cool to see them out in the river," Buck said.

Nothing to worry about

Smaller Sea Lamprey

This 13-centimetre sea lamprey has been in the river system for about four years, says Laura Buck, a field technician with Fort Folly Habitat Recovery. (Fort Folly Habitat Recovery)

Most people don't notice young sea lampreys because they're still fairly small before going out to sea.

The older, bigger fish might look a bit scary, Buck said, but they are not dangerous.

Buck said she's seen bite marks on other fishes from lampreys, but has never heard a case of a human being bitten.

"Don't be scared, they are not going to do anything to you." she said. "I've been working in the Petitcodiac watershed for 13 years now, and I've never had any encounters with a lamprey."

"No one should be concerned," she said. "They are harmless."

A happy catch

In fact, Buck called the catch "a very nice surprise" and said the field technicians were lucky to catch the fish.

Due to the size of the sea lamprey, she estimates it is likely in the last stage of its life.

Sea Lamprey

Fort Folly Habitat Recovery is conducting research in salmon recovery in the Petitcodiac watershed. (Fort Folly Habitat Recovery)

"It's just sort of spending the rest of its life floating around in the river and swimming until it's finished its life cycle." 

Buck released the big lamprey back into the river.

Fort Folly Habitat Recovery is gathering baseline data on several migratory species, including sea lampreys.