August 25, 2026 — Atlantic mackerel have long followed a predictable seasonal migration across the Northwest Atlantic. Each spring, mackerel move north from southern New England and the Mid-Atlantic—through Georges Bank and along the Scotian Shelf—toward the Gulf of St. Lawrence and Newfoundland. Then, they return south as ocean temperatures start to cool in the fall.
In recent years, that familiar pattern has become less predictable. Throughout a period of persistent warming across the Northeast U.S. shelf, several marine species were observed shifting northeast and into deeper waters. But beginning in 2024, an unusual period of cooler ocean conditions across the region drew attention from both scientists and fishermen. As scientists and fishermen documented widespread cooling, delayed migrations, and species redistributions, fishermen began reporting an apparent uptick in Atlantic mackerel—sometimes in unexpected locations.
The Atlantic Mackerel Cooperative Research Initiative is looking at which ecosystem drivers are influencing the increased mackerel population and shifting migration patterns.