Is it finders keepers or a kind of hostage taking when a commercial fisherman “rescues” an oceanographic buoy adrift off Monterey, Calif., and won’t give it back to the U.S. Geological Survey until the agency pays him for his trouble?

Daniel Sherer, 39, owns the 30-foot commercial fishboat Irish with partner Patrick Anderson. He was trapping Pacific hagfish in January — hagfish resemble eels and are prized in South Korea for the dinner table — when he came across the approximately 4-foot-diameter buoy floating 5 miles off Monterey, said his father, David, a semiretired lawyer and his son’s original legal counsel in the case.

The fish captain turned his boat around to get a closer look, tangled his running gear in the buoy’s mooring cables and hauled the scientific gear aboard, Sherer said. He said his son didn’t know exactly what he had. For all he knew — or still knows, for that matter — it could have been a submarine detection buoy.

“You think they’re going to tell us that’s what it is?” Sherer said. “No.”

Whatever it was, it was a hazard to navigation, as the lawyer’s son discovered when his boat became snarled in the cable.

His boat still dragging the wire, the fishing captain slowly motored to Moss Landing Harbor — a major commercial fishing harbor on Monterey Bay — so as not to damage Irish. He had seen an “800” telephone number stenciled on the side of the buoy, so he dialed the number and left a message that he’d found the scientific gear, taken possession of it and that it was on the Irish in the harbor.

He told the agency it would have to pay for the buoy’s return, a demand that amounted to “holding the equipment as a de facto hostage,” according to the government. That’s what Department of Interior assistant field solicitor Karen D. Glasgow said in a Feb. 19 response to a letter from lawyer Sherer that offered to sell the buoy back to the USGS for $45,000 — a little more than 10 percent of the $400,000 he estimated the buoy to be worth.

The U.S. Attorney’s Office filed suit March 31 in U.S. District Court in San Francisco against the boat’s two owners and their company, A&S Fishing. The government says the buoy — Scientific Mooring MS1 — had been anchored to the bottom in the Monterey canyon at a depth of about 300 meters as part of a seven-buoy array tethered at various depths to measure turbidity currents — their velocity and sediment concentrations — during the El Niño winter months of October 2015 until April.

The government complaint said that on or about Jan. 15 the buoy broke loose from its mooring in a storm and floated to the surface. Two days later its homing beacon alerted the USGS that the buoy was in Moss Landing Harbor; two days after that Irish’s captain notified the USGS that the buoy was in his possession and he wanted money for its return.

David Sherer maintains that as soon the buoy tore loose from its anchor and popped to the surface, it was anyone’s to claim. “Attached to the bottom, it belongs to the government,” he said. “Floating on the surface, it’s finders keepers under salvage law.”

Sherer argues that his son now owns the buoy. In any case, he says, the government owes his son compensation for seven or eight fishing days lost while he hassled with the government about the buoy, for possible damage to Irish’s transom when the captain hoisted the buoy aboard and to the transmission when the cable became caught in the running gear, and for the cost of a diver to untangle the cables from the boat.

The government strenuously disagrees. “Your client has no claim or right to possession of the said equipment and, indeed, your client’s continued possession will cause damages to the United States,” Glasgow wrote. “The United States therefore demands the immediate return of its equipment to the USGS.”

She said that if Sherer thinks his son has a legal claim to remuneration he should pursue it in an “appropriate” way.

And there the matter remained — a stalemate — until the government filed suit asking the court to order Sherer’s son to give the buoy back. The lawsuit seeks as much as $115,000 for damage to the buoy — its instruments, data and water samples — and for the delay of an important research program that involved multiple universities and several countries. The program was supposed to resume in April, when the USGS had planned to recover the buoy, download data and redeploy it.

“It’s a salvage case, if anything,” said New York maritime lawyer James Mercante of the New York firm Rubin, Fiorella & Friedman LLP. He said the government did not abandon the buoy; it was part of an ongoing research project.

Mercante said Daniel Sherer should have surrendered it to the USGS in a timely fashion, and if he thought the government owed him remuneration for finding and recovering the buoy, he should have asked for it. If the sides couldn’t agree on an amount, he could go to arbitration or, if necessary, to court for a decision, Mercante said.

“They’re in a sticky wicket now,” Mercante said. Instead of returning the data buoy and making a claim against the government for a salvage award, the fishermen are now defendants in a federal lawsuit seeking an award for damage to the buoy and to the oceanographic project, Mercante said.

“They’ve got a tiger by the tail, unfortunately,” he said.

Mercante noted, too, that under Article 4, Section 3, Clause 2 of the Constitution, only Congress has the right to dispose of government property. He said the courts have held that the federal government does not abandon property unless it says it has.

In short, the fishermen are on the wrong side of the law on this one, Mercante said. “I fought the law, and the law won,” he said, quoting a line from the song the Bobby Fuller Four popularized in the 1960s.

Mercante noted, too, that it usually is best to seek the advice of a maritime lawyer in a maritime case. “If you have a foot problem, you don’t go to an eye doctor,” he said.

Daniel Sherer has fired his father as his lawyer — which David Sherer confirmed to Anglers Journal — and is asking for $13,000 in compensation, according to published reports. He did not respond to an email seeking comment. The U.S. Attorney’s Office said it does not comment on pending cases.