PORTLAND, Maine (AP) -- America's lobster fishing business dipped in catch while grappling with challenges including a changing ocean environment and new rules designed to protect rare whales.

The lobster industry, based mostly in Maine, has had an unprecedented decade in terms of the volume and value of the lobsters brought to the docks. But members of the industry have also said they face existential threats from proposed rules intended to protect the North Atlantic right whale and climate change that is influencing where lobsters can be trapped.

Maine fishermen's catch in 2023 fell more than 5% from the year that preceded it, and the total of 93.7 million pounds of lobsters caught was the lowest figure since 2009, according to data released Friday by the Maine Department of Marine Resources. The figure tracks with the up-and-down year lobster fishermen experienced, said Dave Cousens a fishermen based out of Criehaven island and a former president of the Maine Lobstermen's Association.

The price of bait and fuel eased somewhat, but the volume of catch didn't seem to match other recent years, Cousens said. The Maine lobster haul has fallen from a high of 132.6 million pounds in 2016, though the 2023 year's figure was still much more than fishermen produced in most of the 2000s. The 2023 haul was also the second year in a row the total catch declined.

Fishermen who participate in Maine's lifeblood lobster industry are on edge about what the future holds, as lobsters have inched steadily northward as waters have warmed, Cousens said.

"We've gone down steadily from 132 million. We're going back downhill," Cousens said. "There's no question climate change is affecting it."

Fishermen from Massachusetts, Rhode Island and other Northeast states also harvest lobsters with traps from the cold waters of the Atlantic Ocean, but about 80% comes to the docks in Maine in a typical years.

The price of lobsters at the docks has ebbed and flowed in recent years, but it has stayed fairly consistent to consumers. The price at the docks spiked to more than $6.70 per pound in 2021 and fell to less than $4 per pound in 2022. Last year, it was a little less than $5 per pound, and the total catch was worth more than $460 million at the docks, according to data released Friday. That is the third highest figure of the last four years.

"The price Maine lobstermen received last year is a reflection of the continued strong demand for this iconic seafood," said Maine marine resources Commissioner Patrick Keliher.

The state's fishermen have been in a lengthy legal battle with the federal government over rules designed to protect the whales, which are vulnerable to entanglement in fishing gear. The fishermen argue the proposed rules are so strict they could put them out of business, but conservationists say they are essential to save the whales, which number less than 360 in the world. A right whale found dead off Massachusetts this winter showed signs of entanglement in Maine gear.

The ways in which climate change is affecting the industry are a subject of ongoing scientific study. The southern New England lobster industry has collapsed as the ocean has warmed, and the waters off Maine logged the second-warmest year on record in 2022.