Don Mohr knew where all the fish were. When he died last week, a chilly breeze blew over the Vineyard waters. For many of us Mr. Mohr was synonymous with the Martha’s Vineyard Striped Bass and Bluefish Derby.

He died on Thursday, Sept. 20, in Atlanta, Ga., at the age of 89.

The unofficial mayor of Wasque, Don Mohr presided over the comings and goings of fish, birds and fishermen. When you saw him at the beach, you knew it was the right time to fish — not necessarily because the fish were running but because you knew if Don was there you would have a good time. He had that ability to create a memorable moment out of thin air.

He fished many places. We heard stories of him reeling in fish at the Brickyard in Chilmark and all the beaches from Aquinnah to East Beach. At times it got a little bit confusing, the reports of the different spots on the Vineyard where he was seen reeling in fish. How could he be in all those places at once?

But Wasque was Don Mohr’s regular appointment, and he would preside over the fast-moving currents at the rip there from the start of the fishing season in spring to the last fall migration at derby time. Don was chairman of the derby for many years in the 1980s.

And he was never very far from his wife, Marian. The two Mohrs were seen frequently together out fishing, and if you stopped to talk to them, which you inevitably did, you would often hear one begin a sentence and the other finish it.

Early in the 1980s, the Martha’s Vineyard Striped Bass and Bluefish Derby went through a change as it moved out from under the wing of the Martha’s Vineyard Chamber of Commerce to become an independent institution in its own right.

The derby slogan in those early years was “Fishing contest for fishermen, run by fishermen.”

Ed Jerome, today president of the derby and also for a time back then, before handing the reins to Mr. Mohr, remembers those years. “He took the derby to the next level,” Mr. Jerome said. “He was sharp with his organizational skills. He ran a no-nonsense meeting. But he was also hilarious.”

Mr. Mohr naturally brought his skills as a previous college athletic director to this new job of running the derby. His philosophy was to be open and transparent about the derby, and he knew this was the way to bolster public trust in and support for the institution.

And there were other challenges. Striped bass were removed from the derby for several years during a crisis in the stocks which had dwindled to record low levels. Mr. Mohr handled it all with cool professionalism, never wavering from the derby’s central mission as a high-quality sportfishing contest with a public conscience.

Four years ago, Marion Mohr hosted a private 85th birthday party for Don in their home in West Tisbury. There were plenty of fish stories that night as a wide array of anglers gathered around the veteran fisherman who had been their leader.

At one point Mr. Mohr pulled out a log he had kept through his years of shorefishing on Vineyard beaches. The log included notes about the fish and tides, currents and weather conditions. It also included the long list of fishermen Mr. Mohr had met along the way.

Even so, the list of people Mr. Mohr touched throughout his long life could not be contained within two covers.

He will be missed.