Stephanie Merrill of the Conservation Council of New Brunswick said LaPierre's departure calls into question his work for the provincial government, which included a report on shale gas regulations last year that recommended the creation of the institute he was later hired to lead.
"Given that it was his recommendation and it created a job for him to specifically chair for three years ... this certainly adds to the skepticism," Merrill said.
LaPierre stepped down from the institute and various positions at the University of Moncton after conceding this week that he misrepresented his academic credentials. In various biographies, LaPierre said he had a PhD in ecology from the University of Maine, but that university said it has no record of him earning that degree.
He could not be reached for comment.
LaPierre's resignation comes as the government wrestles with whether to allow the shale gas sector to expand in the province. The idea has stoked outcry from critics and Merrill said she believes LaPierre's exit will only bolster the resolve of those opponents.
"I think it certainly does give the movement another piece of momentum," Merrill said.
She said because there's a cloud now cast over LaPierre's work, there should be a review of his research by someone without links to the government or the shale gas industry.
Alward said while he felt disappointed after LaPierre's resignation, he doesn't think it impairs the good work he and the institute have done and it's premature to be ordering reviews.
"He was able to bring together world-leading scientists to a program they saw as innovative to really make a difference and better understand the shale gas sector here in New Brunswick," Alward said in an interview.
"It is my hope that they will be able to find a way forward to allow the work that needs to be done."
The government has introduced a list of industry regulations it says would allow the shale gas industry to grow in the province while protecting the environment.
Alward has promoted shale gas development as a way of stimulating much needed job growth and revenue for the province.
Opponents say they fear that fracking — a process that uses water and chemicals under pressure to released trapped shale gas — will put groundwater at risk.