As much as half a million kilograms of haddock caught on the rich fishing grounds of Georges Bank this weekend will be landed in ports in southwestern Nova Scotia, as the winter fishery gets underway after a storm-delayed start to 2018.

The fishing grounds are a 10- to 12-hour trip by boat from the tip of southern Nova Scotia.

Georges Bank is so productive that the fish hatched in a single year can keep fish plants going for several years.

Between 85 and 90 per cent of the fish landed this weekend, for example, will be from 2013, when a billion haddock were hatched on Georges Bank.

An elevated area of sea floor larger than Massachusetts separates the Gulf of Maine from the Atlantic Ocean. It also straddles the offshore boundary between Canada and the United States.

Haddock are among the fish found on the lucrative fishing grounds of Georges Bank. (CBC)

These days, storm clouds of another kind are on the horizon in the form of a proposal by the Trump administration to allow offshore drilling in virtually all U.S. federal waters, including on the American side of Georges Bank.

"Up until this announcement, it was taken for granted: There was no activity," says Leo Muise of the Nova Scotia Seafood Alliance, a fishing industry association. "There was no reason to get talking about it. Clearly there is now."

What Trump is actually doing

On Jan. 4, the U.S. Bureau of Ocean Energy Management issued a draft proposal for oil and gas leases that opened 90 per cent of outer continental shelf waters to petroleum exploration.

The proposal contemplates opening the North Atlantic zone — which includes Georges Bank — to oil and gas development in 2021 and 2023.

The bureau estimates potentially recoverable hydrocarbons under the North Atlantic zone have a net economic value, which is calculated as gross revenues minus cost of extraction, of up to $74 billion.

President Donald Trump holds a signed executive order in April 2017 directing the Interior Department to begin reviewing restrictive drilling policies for the outer-continental shelf. (The Associated Press)

The entire North Atlantic zone is estimated to hold 1.7 billion barrels of oil, about the equivalent of the Hibernia field off Newfoundland. The bureau estimates there is 11.76 trillion cubic feet of natural gas — which is several times larger than the ExxonMobil Sable project — off Nova Scotia.

Production from exploration and development in newly available offshore areas will likely not occur for a decade or more, and then will continue for another 30 to 40 years or longer, the bureau says.

It remains to be seen whether there is interest from the oil industry in Georges Bank. There were a number of unsuccessful exploratory wells drilled on the U.S. side before the area was put off limits in the late 1980s.

Why Trump's move is so 'awkward'

Canada and the U.S. jointly manage fisheries on Georges Bank through various trans-boundary committees that agree on quotas, resource sharing and stock health.

Leo Muise expects that kind of consultation and co-operation if oil and gas go forward on the U.S. side of the line.

Leo Muise is executive director of the Nova Scotia Seafood Alliance, a fishing industry association. (CBC)

"It is awkward. It's one fishing bank that has a border running through it," he says.

"Presumably before any licences are issued and people got working, the United States government will be consulting with their Canadian counterparts and both governments will be working through it the same way they do when they are setting fishing limits."

Canadian response on Georges Bank

CBC contacted three Canadian government departments — Global Affairs Canada, Natural Resources Canada and the Department of Fisheries and Oceans — for a response.

A spokesperson for Natural Resources issued the holding lines — talking points put out when you don't want to, or cannot, address an issue in detail.

A spokesperson for the federal Natural Resources department says the government is "committed to the protection of Georges Bank as well as the fishing industry." (Canadian Press)

Not surprisingly, the department said it is "not in a position to speculate" on the draft proposal.

"The Government of Canada recognizes the importance and environmental sensitivity of the Georges Bank area," Jocelyn Argibay said in an emailed statement.

"Together, the Governments of Canada and Nova Scotia are committed to the protection of Georges Bank as well as the fishing industry that provides a livelihood to many people in the area, and we have taken steps to protect this valuable ecosystem. We will monitor any developments closely."

U.S. moratorium lapsed in 2008

Canada's side of Georges Bank has been under federal government moratorium since 1988. The current 10-year ban expires in 2022.

On the American side, a moratorium was imposed through an executive order known as a presidential withdrawal that removed the North Atlantic continental shelf from consideration for oil and gas exploration.

The presidential withdrawal that covered Georges Bank was in place from 1990 to 2008. It was ended in 2008 by George W. Bush and never reinstated by his successor, Barack Obama.

The entire North Atlantic zone is estimated to hold 1.7 billion barrels of oil, about the equivalent of the Hibernia field off Newfoundland. (Submitted by Dave Hynes)

Under Obama, the U.S. had several opportunities to allow drilling in the North Atlantic zone when federal waters were periodically put up for oil and gas development. The North Atlantic was never included in U.S. plans under Obama, perhaps leading to complacency.

"It was a non-issue. People thought no news is good news," says Leo Muise.

More bad news for the North Atlantic right whale?

There are other questions about how Canada and the U.S. would handle a situation where oil and gas exploration is allowed on one side of the line but not the other, especially as it affects the highest-profile trans-boundary species: the critically endangered North Atlantic right whale.

Both countries are co-operating to try and save the whales, which suffered a catastrophic run of deaths in the Gulf of St. Lawrence in 2017.

Conservation groups are concerned about the potential impact of drilling on whale populations. (Center for Coastal Studies)

Canada has responded — some say belatedly — with a series of measures to control ship strikes and gear entanglements in that area.

Regina Asmutis-Silvia, the executive director of Whale and Dolphin Conservation North America in Cape Cod, says as Canada is taking steps to enhance protections for right whales, the U.S. is reducing protections by allowing oil and gas exploration in their habitat.

"The impacts that seismic, construction noise, drilling and platform establishment have is significant for all the marine species. But the potential for a spill will have an even bigger impact. The spill isn't going to stop at the U.S.-Canada border, either."