A superior court judge has ruled that the Oak Bluffs conservation commission had the authority to deny a homeowner’s request to build a pier into Lagoon Pond on the grounds that the structure could harm shellfish beds.

In a memorandum decision, the Hon. Richard J. Chin said the town’s wetlands bylaw and pier regulations adopted under it are intentionally stricter than what the state Department of Environmental Protection requires, so cannot be invalidated by the DEP. Further, he said, the conservation commission’s action in denying the particular pier was supported by substantial evidence.

The homeowner has 30 days to appeal the decision, which was issued on Sept. 22.

In April 2012, Oak Bluffs homeowner Nancy Perkins sought a permit to build a 63-foot pier to enable her to access her boat mooring in Lagoon Pond. According to court documents, the pier was designed to minimize impact on shellfish beds and included a plan to plant new shellfish seeds at the rate of 2:1 for any areas disturbed during construction. Five of the 11 homes in her area have piers, the court noted.

After two hearings, the commission denied the project, citing a range of potential negative impacts including to marshland, shellfish beds, water quality and recreation. The homeowner received a superseding order from the state DEP approving the project with minor revisions, and submitted a new project plan in July 2013. At a hearing in August, experts gave conflicting views about the potential impact to shellfish and shellfish habitat. In September 2013, the commission denied the project again.

In his decision, Judge Chin ruled the DEP could not supersede the commission’s decision. In addition, he noted that the commission relied in part on an assessment report from shellfish constable David Grunden who found the site was good habitat for softshell clams and was within the softshell mapping habitat of the state Division of Marine Fisheries.

“Where the commission, in the discretionary exercise of its expertise, makes a choice between two fairly conflicting views, and its selection reflects reasonable evidence, the court may not displace the commission’s choice,” the judge ruled.