In 1851, there were 60 Provincetown-owned vessels weighing a total of 4,332 tons pursuing mackerel; the fishery employed 688 men and boys. In 1864 the catch was so great, the year was referred to as the Boon Island Year.

It didn’t last. By 1871, the price haddropped to the point where “it scarcely paid to catch them,” reported one source. When the railroad was built, two years later, prices soared again, as now other markets besides Boston could be reached.

Today mackerel are often considered bait fish for stripers, bluefish, and bluefin tuna, but they also lend themselves to many Portuguese dishes. They remain plentiful off Cape Cod.