How climate change impacts alewives and other migrating fish in Maine
If you have ever experienced an alewife migration, you know it is a true Maine experience that you must see to believe. As temperatures warm in Maine, alewives are beginning their remarkable migration into the Gulf of Maine. These small but mighty fish face new challenges as climate patterns shift.”I love alewives, I think they are the most important fish in the sea and the river and the lake,” says Zach Whitener, Research Associate at the Gulf of Maine Research Institute. “When you see them scurrying up their brooks, they’ll swim on their side through half an inch of water. They are such determined to get where they want to go.” Alewives join several species including blueback herring, American shad, and Atlantic salmon that migrate from ocean to freshwater. “These are anadromous fish, which means they live in the ocean as adults, but they spawn in freshwater,” Whitener explains. “In freshwater, the fish don’t have much competition as juveniles.”After feeding in the ocean for three to four years, these fish return to their birthplace to spawn in the same lakes where they were hatched.The Gulf of Maine serves as a “grocery store for most of the North Atlantic,” but climate change is creating complex challenges for migrating fish.”It’s a lot more complex than just it’s warmer in the spring,” notes Whitener. While temperature drives adult migration, changing precipitation patterns also create obstacles.”If there’s too much water coming down or too much flow, that will slow them down,” Whitener explains. “With a changing climate, we’re getting different precipitation patterns and the amount of runoff is changing.”Juvenile alewives face particular difficulties: “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. Conversely, if there is a very big storm, they might get flushed out of their lake when they didn’t want to. The delayed or sped up migration can really affect these fish later in their lives.”Despite these challenges, anadromous fish continue to display resilience. Research continues to monitor how these species adapt to challenges associated with human-induced climate change, seeking the best management approaches to protect these important indicators of our changing ecosystem. Experiencing an alewife migration is a natural wonder you must see to believe. Viewing the species migration is possible across Southern Maine, as they embark on their journey into the Gulf of Maine, including the Mousam River (Kennebunk), Mill Brook Preserve (Westbrook) , Androscoggin River (Brunswick) to name a few.
If you have ever experienced an alewife migration, you know it is a true Maine experience that you must see to believe. As temperatures warm in Maine, alewives are beginning their remarkable migration into the Gulf of Maine. These small but mighty fish face new challenges as climate patterns shift.
“I love alewives, I think they are the most important fish in the sea and the river and the lake,” says Zach Whitener, Research Associate at the Gulf of Maine Research Institute. “When you see them scurrying up their brooks, they’ll swim on their side through half an inch of water. They are such determined to get where they want to go.”
Alewives join several species including blueback herring, American shad, and Atlantic salmon that migrate from ocean to freshwater. “These are anadromous fish, which means they live in the ocean as adults, but they spawn in freshwater,” Whitener explains. “In freshwater, the fish don’t have much competition as juveniles.”
After feeding in the ocean for three to four years, these fish return to their birthplace to spawn in the same lakes where they were hatched.
The Gulf of Maine serves as a “grocery store for most of the North Atlantic,” but climate change is creating complex challenges for migrating fish.
“It’s a lot more complex than just it’s warmer in the spring,” notes Whitener. While temperature drives adult migration, changing precipitation patterns also create obstacles.
“If there’s too much water coming down or too much flow, that will slow them down,” Whitener explains. “With a changing climate, we’re getting different precipitation patterns and the amount of runoff is changing.”
Juvenile alewives face particular difficulties: “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. Conversely, if there is a very big storm, they might get flushed out of their lake when they didn’t want to. The delayed or sped up migration can really affect these fish later in their lives.”
Despite these challenges, anadromous fish continue to display resilience. Research continues to monitor how these species adapt to challenges associated with human-induced climate change, seeking the best management approaches to protect these important indicators of our changing ecosystem.
Experiencing an alewife migration is a natural wonder you must see to believe. Viewing the species migration is possible across Southern Maine, as they embark on their journey into the Gulf of Maine, including the Mousam River (Kennebunk), Mill Brook Preserve (Westbrook) , Androscoggin River (Brunswick) to name a few.