June 5, 2025 — Some fish stay in the same cozy bodies of water all year long. Others, like the alewife, a fish found in the waters of the Northern Atlantic Ocean, migrate between different areas to spawn and live. But changing weather patterns are affecting alewife migration, potentially harming their entire lifecycle, reported WMTW News 8 Portland.
What’s happening?
Alewives are anadromous fish; they spawn in freshwater but live the rest of their lives in saltwater. They’re commonly found in the Gulf of Maine, where they live and feed for a few years before returning to the freshwater areas they spawned in to start a new lifecycle.
Zach Whitener, research associate at the Gulf of Maine Research Institute, told WMTW News 8 Portland that the changing climate, namely, changing precipitation patterns, is affecting alewives and other migrating fish species.
“If we haven’t had enough rain and the lake level isn’t high enough, they can’t physically get out of their lakes when they want to,” said Whitener. “Conversely, if there is a very big storm, they might get flushed out of their lake when they didn’t want to.”