The Department of Fisheries and Oceans says it has known for years that fishermen on the Tusket River were worried that the wrong type of fish ladder was being used at the Nova Scotia Power facility where thousands of gaspereau were found dead last week.
But Mike Wambolt didn't explain why nothing has been done to alter the ladder.
"DFO has been aware and have been looking at that for a number of years," said Wambolt, the manager of the fish and fish habitat protection program for DFO in the Maritimes.
"It is a challenge. There's lots of work going on on the other side, on the main dam fish ladder. This was just an unfortunate incident that occurred adjacent to this fish ladder at that time."
Troy Doucet, co-chair of the Yarmouth-Shelburne Gaspereau Advisory Committee, said Tuesday that more than 100,000 fish died in the incident at the Nova Scotia Power powerhouse, which is just down river from the company's hydroelectric dam. The facility is about a 15-minute drive from Yarmouth.
Doucet said part of the problem is that the fish ladder by the powerhouse is designed for salmon, not gaspereau.
"The fish ladder isn't adequate for all species, correct. We are working to address that."
He said the gaspereau made their way to a pool near the powerhouse during a "high tide event," and became trapped when the tide went out.
Wambolt said an investigation is underway to learn more about what went wrong, and he didn't yet know exactly how many fish died.
Nova Scotia Power says it is involved in that investigation with DFO.
Heather Holland, the utility's director of environment, said they were also aware about concerns about the fish ladders, but their equipment follows the requirements dictated by their permit, issued by the province.
"The effectiveness of that ladder is one thing that we are working with DFO to better understand this migration season," she said. "If adjustments are required, we would look to get direction from DFO."
Wambolt said ordering changes to Nova Scotia Power's permit is one of the regulatory tools at DFO's disposal, but couldn't say when or if the department would make use of it.
"We're still information gathering," he said. "We have to look at the background and history on the fish ladder and we'll continue to work on that."
Holland says it was Nova Scotia Power staff who discovered the dead fish last week.
"This is a very unfortunate incident. We take our compliance as a top priority."
Doucet has criticized how the situation has been handled, noting that local fishermen found out about the fish kill on social media instead of being informed by DFO.
Wambolt said DFO doesn't inform people about about a situation like this while it's under investigation.
As for the cleanup, Wambolt says there's no concern about water quality at this time despite the number of dead fish in the water.
He said there's no timeline for when and how the fish kill will be cleaned up.
"We do have to look at that and continue to collect information."