PORTLAND (AP) — Some of New England’s embattled cod fishermen say they might go out of business because of a new cost the federal government is about to impose on them today.

Fishermen of important commercial species such as New England cod and haddock must pay the cost of fishing monitors under new rules scheduled to take effect today. The monitors, whose services can cost more than $700 per day, collect data to help determine future fishing quotas.

The federal government had been paying the bill, but fishing regulators say there isn’t enough money to do so anymore because of other obligations within the National Marine Fisheries Service.

Fishermen, advocates for the industry and a host of New England politicians have said the cost will sink a fleet already struggling with tight catch quotas and dwindling cod populations. Some fishermen also say a cutback in fishing by New England’s fleet could make popular food species, including flounder, hake and pollock, less available to consumers.

“Somebody’s got to catch it,” said Terry Alexander, a Harpswell, fisherman who is trying to manage the new cost. “We’re going to have to figure our way around it. The law is the law.”

The shift in cost is happening at a time when scientists say the cod stock off New England has collapsed. The Atlantic cod catch sometimes topped 100 million pounds per year in the 1980s, but it fell to about 5 million in 2013 and 2014. Catch quotas have plummeted in that time.

Some scientists have tied the cod’s decline to climate change. A report in Science magazine says the warming of the Gulf of Maine, which sped up from 2004 to 2013, reduced the fish’s capacity to rebound from fishing.

The fishing monitors will accompany New England’s ground fishermen 20 percent of the time, said Jennifer Goebel, a spokeswoman for the National Oceanic and Atmospheric Administration.

The change has been the subject of a lawsuit filed by fishermen in federal court in Concord, New Hampshire, who want to block the cost shift. A judge’s ruling on the lawsuit is expected in about a week.

Goebel said federal officials are awaiting the ruling. Stephen Schwartz, the attorney for the fishermen, declined to comment.