While the rest of us admire fall foliage, North Fork baymen look to nature for signs that predict the health of adult bay scallops. 

They watch the docks and parking lots to see if they are littered with broken scallop shells dropped and picked over by gulls; a good sign. They scan the beaches after a strong wind to see if scallops have washed up; another good sign. 

This year — once again — the signs were not encouraging.

The bay scallop season, which started Monday in New York and runs through March, looks to be just as bad this year as it has been for the past four, which means the most reliable way to get a bay scallop dinner is to know a fisherman — and the most reliable way for a fisherman to make a living is to fish for something else.

On Friday afternoon at a town dock on Shelter Island, Mike Tehan was hosing down his lobster traps and putting away most of his fishing gear but planned to go out for scallops on opening day with a reporter and photographer. Mike’s father, John Tehan, was going to miss opening day this year and, for the first time in years, his uncle, Chris Tehan, had decided not renew his commercial scallop license.

Monday at sunrise (6:26 a.m.), the Clark family’s boats were mostly on the water, and the temperature at Congdon Creek was 44 degrees, a lot chillier than last year’s 58 degrees, but still pretty warm for a fall day, especially one being spoiled by human-caused climate change.

At Southold Fish Market, Charlie Manwaring was wrapped in an apron and up to his elbows in stuffed clams as part of an assembly line that six years ago would have been opening a mound of bay scallops as baymen brought in bushels. As of 1 p.m., Mr. Manwaring had not seen any scallops, but he thought by Tuesday they would have some. 

Over at Braun’s in Cutchogue, the phone was ringing non-stop with customers wanting to know if they had scallops. Manager Keith Reda had taken the day off, confident that there would be no avalanche of bivalves this year. By late afternoon at Braun’s, Cathy Blasko was opening the two bushels of bay scallops that had come in. They would go on sale as soon as she finished.

The season opened with an interesting range of pessimism. At one end was Wayne King, who scalloped on the very last day of the season in March and was out again Monday with his wife, Donna. Mr. King, who is “over 80,” guessed that he might be the oldest Shelter Island bayman on the water this opening day, and there was no one around on land or sea to refute it. 

He and his wife came back with a bushel of scallops, having obviously enjoyed themselves.

At the other end was Tim Sweat, a die-hard bayman who came steaming into Greenport after covering the entire length of the Peconic Bay system — Riverhead to Flanders, Jamesport to Shinnecock — with just a bushel to show for a long day. He vowed this would be his only day of scalloping for a while. Year after year of poor scallop harvests have convinced him to focus his efforts on a more lucrative fall catch: conch (whelk).

“You see these scallops? These are adult scallops; they should be the size of my palm. This one is half the size,” said Mr. Sweat, who was tired, and angry about the overdevelopment of near-shore land for second homes. “The people who are in charge on land are not doing anything for the people on the water.”