Some fish species that had disappeared from the Petitcodiac River are back, thanks, in part, to the reopening of the Petitcodiac River causeway gates three years ago.

The causeway linking the City of Moncton and Town of Riverview was built in 1968 but had unforeseen consequences on the ecosystem and the fish species that have historically called the river home.

Several fish species suffered as a result as the causeway blocked fish migration through the Petitcodiac River system.

Although the causeway had a passageway to allow fish upstream, it was inefficient for most species, according to the Fort Folly Habitat Recovery Program website.

Species such as striped bass and salmon disappeared for the most part from the river.

But since the causeway gates were opened in 2010, numbers have been rising rapidly.

Edmund Redfield, a scientist with the Fort Folly Restoration Project, said he’s conducted a fish count every year since the gates opened.

"You want to get any number of species that have been historically present in the river but that were excluded by the causeway — to get them back in the river, that's how you get a functioning ecosystem again is to put the different parts back together in it," he said.

Redfield said restoration is going better than he had originally expected.