PORTLAND, Maine (AP) — Several commercial fishermen in New England have been sentenced in a fraud scheme that centered on a critically important species of bait fish and that prosecutors described as complex and wide-ranging.

The fishermen were sentenced for “knowingly subverting commercial fishing reporting requirements” in a scheme involving Atlantic herring, prosecutors said in a statement. The defendants included owners, captains and crew members of the Western Sea, a ship that operates out of Maine.

Western Sea owner Glenn Robbins pleaded guilty in March to submitting false information to the federal government regarding the catch and sale of Atlantic herring and a failure to pay taxes, prosecutors said. Members of the ship’s crew conspired to submit false trip reports to the federal government from 2016 to 2019, court records state. The charges are misdemeanors.

Robbins was sentenced Thursday to two years of probation and a $9,500 fine. The false reports threatened to jeopardize a fish species that is vitally important as commercial lobster bait, said federal prosecutor Darcie McElwee.

“The defendants in this case subverted regulations for the sole purpose of lining their own wallets — regulations that are in place to ensure Atlantic herring are not overfished and are available for future generations of fishermen and safeguard the viability of the marine ecosystem,” McElwee said.

Reached by phone on Monday, Robbins said that despite his plea, he doesn’t consider himself to be guilty and that he took a plea deal because of the uncertainty of taking the case to a jury.

“We took the plea deal just so we wouldn’t be felons,” Robbins said.

A federal judge also sentenced a part-time captain and three crew members to similar sentences last week. Those defendants all pleaded guilty in March.

Four other defendants were sentenced earlier in the year and received similar sentences. All of the defendants in the case are based out of Maine or New Hampshire.

Federal rules require fishermen to submit trip reports about the species they caught, the weight of a catch and the dealers who buy the fish.

Herring is an important part of the food chain, as it is eaten by marine mammals, larger fish and seabirds. Fishing managers have raised concerns about the sustainability of the Atlantic herring population in recent years.