The effects of a tanker port and increased tanker traffic off the west coast will be front and centre at hearings into the proposed Northern Gateway pipeline this week, as proponents and critics convene for another round of hearings.

The panel reviewing the plan to build 1,100-kilometre twin pipelines will arrive in Prince Rupert, where participants will be questioning witnesses under oath about the environmental and socio-economic effects of the marine terminal and the increased shipping it will bring to the B.C. coast.

"(We) have focused on potential impacts to wildlife, particularly marine mammals such as humpback whales and there's the northern resident killer whale that could potentially be impacted by the increasing traffic of oil tankers should this project go ahead," said Tim Leadems of Ecojustice, which is representing a coalition of environmental groups at the hearings.

The Pacific humpback whale is listed as an endangered species under the federal Species At Risk Act.

Ecojustice launched a lawsuit against the federal government in September claiming that Ottawa's failure to implement protections for the whales and other endangered species legislated under the act is further endangering wildlife along the proposed route.

During the last round of hearings this fall in Prince George B.C., several intervening groups probed company and federal officials about the effects on endangered caribou populations.

So far, Enbridge engineers, experts and consultants have been grilled on everything from earthquake and tsunami risks, pipeline routes, and compensation for habitat loss at the Prince George hearings. Earlier hearings in Edmonton looked at the economic effects and viability of the project.

John Carruthers, president of Enbridge Northern Gateway Pipelines, said the company has recognized as the hearing process unfolds that it must take steps to build confidence in the project.

"We'll continue to look at how do we build confidence, because I think that's something that we recognize: people need more confidence we can build and operate the pipeline safely," Carruthers said in a recent interview.

"We recognize we have to create a forum where we can have good dialogue with even those who oppose. It's not that we haven't tried, but we have to get in...more just listening and understanding."

Enbridge (TSX:ENB) has estimated that opening up Asian markets to Canadian oil would boost Canada's GDP by $270 billion over 30 years and generate $81 billion in direct and indirect revenues to the federal and provincial governments.

Critics of the project are expected to continue to question company and federal officials about legislative changes that have come into effect -- or will -- since the hearings began.

Few of the pieces of federal legislation that affect the project have gone untouched in the past year: The Fisheries Act, the Canadian Environmental Assessment Act, the Navigable Waters Act, the National Energy Board Act, the Marine Liability Act.

Enbridge company officials were questioned under oath about the lobbying efforts they've made in Ottawa.

Nikki Skuce of ForestEthics, one of the interveners at the hearings, pointed out to the panel last month that Enbridge has met 145 times since July 2008 with government officials.

"They've done some serious lobbying on reducing regulations, so I don't think that bodes well into building confidence, regardless of what they'll say that they'll do in terms of water crossings of looking at fish or what have you," Skuce said in an interview.

The panel will release its report the last week of December 2013 -- a deadline set by the federal government.