Nalcor estimates that mercury levels will keep rising in fish around Muskrat Falls for up to 15 years after the river is dammed to generate electrical power.
The Crown corporation held an open house in Happy Valley-Goose Bay to answer question about how its plans to tap hydroelectric power on the Churchill River will affect fish habitat, and what the effects may be downstream.
Residents who attended the meeting were also told that contamination levels of methyl mercury are not expected to start dropping until about 30 years after a section of the lower Churchill River is flooded.
Hollis Yetman, vice-president of the Labrador Hunting and Fishing Association, said Wednesday's meeting did not alleviate his concerns about pollution, and whether fish will be safe to eat.
"I hear there's going to be lots of studying, but there's no one here going to tell you that you're going to be able to eat the fish without methyl mercury poisoning in the future," he said.
The Department of Fisheries and Oceans has not yet made a decision on Nalcor's fish habitat plan.
Thirteen species of fish use the Churchill River in the area that will be flooded to form a reservoir of 41 square kilometres.
Biologist Jim McCarthy, Nalcor's technical expert on the aquatic environment at the Muskrat Falls site, said the project will mean changes.
"The biggest difference is [that] there's going to be flooding, so a lot of the areas in the Muskrat Falls reservoir location that are fast-flowing habitat - it's obviously going to be slower moving habitat," he said.
"So the fish species that are [in] those areas for certain life cycle stages, that habit is not going to be available anymore."
He said fish like brook trout and pike that depend on fast water will have to go elsewhere.
The Newfoundland and Labrador government sanctioned the Muskrat Falls project in December.