HALIFAX -- A fishermen's group has asked the Nova Scotia Supreme Court to set aside provincial approval of a massive tidal turbine in the Bay of Fundy, saying the decision was based on poor scientific data.

The 1,000-tonne underwater generator was installed on the floor of the Minas Passage in November, but the Bay of Fundy Inshore Fishermen's Association has said the test project should be put on hold to ensure the bay's productive ecosystem is not harmed.

Nova Scotia's test turbine stands about 10 storeys tall and can generate two megawatts of electricity -- enough to supply about 500 homes. It is anchored on the seabed at the mouth of a five-kilometre-wide channel near Parrsboro, where the crushing currents can travel at five metres per second.

David Coles, the lawyer representing the 175-member association, told the court Wednesday that Environment Minister Margaret Miller overstepped her authority last June because the company behind the project -- Cape Sharp Tidal -- did not submit enough scientific data about the state of the bay prior to installation.

"The minister was required to consider certain things, and they're just not in the record," Coles told Justice Heather Robertson.

Coles said Miller's decision was unreasonable because the company drafted an environmental monitoring program without first compiling enough "relevant baseline data" about the bay's ecosystem, as spelled out in the province's environmental regulations.

The lawyer also cited letters submitted by the federal Fisheries Department that indicated the company's monitoring program "will provide only a limited understanding of the interaction with the marine environment."

Sean Foreman, a lawyer representing the Environment Department, insisted the province had dealt with concerns raised by federal officials regarding data gaps.

"There is no serious disconnect in how this process unfolded," Foreman told the court. "We've had seven years of extensive study. Is it perfect? Absolutely not. It is required to be perfect? Absolutely not."

In the end, federal Fisheries officials said they were satisfied with the steps taken to protect and monitor the environment, he said.

Cape Sharp lawyer Harvey Morrison suggested it wasn't the court's role to decide the value of scientific data.

"The relevance (of the baseline data) is determined by the regulator," he told the court, referring to the provincial Environment Department. "There is no holy grail for the baseline."

The fishermen have long argued the project requires more study to ensure such turbines don't harm marine life in the bay, and they've called for a pause in the project until a year-long study can establish a scientific baseline.

The association has repeatedly stressed that the bay is a rich breeding ground for lobster, groundfish and scallops.

Spokesman Colin Sproul has said the fishermen aren't opposed to renewable energy, they just want to make sure the existing turbine and the ones that follow do not cause irreparable harm.

The turbine, on average, spins at between six and eight revolutions per minute, which is equivalent to a brisk walking speed if the turbine were to roll along the ground. The government has said monitoring at other turbine sites has not recorded a single collision with ocean life.

Robertson reserved her decision to a later date.