Conservationists have heralded the proposed expansion of the Papahanaumokuakea Marine National Monument as critical for the well-being of some 7,000 species of marine life.
But on Friday, scores of opponents to the expansion gathered outside the Honolulu Fish Auction to make their voices heard, saying the proposal would cripple Hawaii's fishing economy.
They say the expansion would increase the no-fishing zone by 350 percent.
"Fifty percent of the fish that landed yesterday, which is 40,000 pounds, was caught from this area," said Nico Chaize, owner of Nico's Pier 38.
Wholesaler Mike Irish puts it a different way.
"Try to imagine that 10 percent, or five or six weeks of the year, the fish are in that territory where we can't get it, and that just happens to be Christmas."
Ahi sashimi is a tradition in Hawaii during the holidays, when demand surges.
Irish says his scenarios wouldn't just be bad for consumers, it would be bad for workers.
"It affects so many other people. The people in all the seafood counters in all the stores, the cutters, the drivers, the dynamics of this," he said.
The expansion would be covered under the Antiquities Act of 1906, which obligates federal agencies to preserve and manage certain public lands. Some opponents think the federal act is too heavy-handed on state autonomy.
"I don't want the federal government to come in and start dictating what we do with the ocean," said former Gov. George Ariyoshi. "We can take care of the ocean."
Office of Hawaiian Affairs Trustee Peter Apo added, "No vetting through Congress, no vetting through the state of Hawaii or our political bodies is just to me, insulting."
A decision on whether to expand the area of protection in the Northwestern Hawaiian Islands could come within the next two months. Should the expansion happen, the marine monument would become the largest area of protected land or sea on the planet.