The last wild Atlantic salmon that return to U.S. rivers have had their most productive year in more than a decade, according to federal and state officials. More than 1,500 of the endangered fish were counted in the Penobscot River in Maine, the only state where they still spawn in the wild.
The greater survival of the salmon could be evidence that conservation measures to protect them are paying off, said Sean Ledwin, director of the Maine Department of Marine Resources sea-run fish programs. The count of river herring is also up, and that could be aiding the salmon on their perilous journey from the sea to the river.
Atlantic salmon were once abundant in American rivers, from Connecticut to Canada, but factors such as overfishing, loss of habitat and pollution reduced their populations to only a handful of rivers in Maine. The fish are known for their remarkable ability to migrate from freshwater to saltwater and back again, sometimes traveling thousands of miles in their lifetime.
The greater survival of the salmon could be evidence that conservation measures to protect them are paying off, officials said. In recent years, several dams have been removed or modified to allow fish passage, and habitats have been restored or enhanced along the river. The Penobscot River Restoration Project, a collaborative effort among federal, state, tribal and private partners, has been hailed as a model for restoring ecological connectivity and resilience.
The Penobscot River once supported runs of salmon in the tens of thousands, in the era before intense damming of rivers, said Dan McCaw, fisheries program manager for the Penobscot Nation. The Native American tribe has lived along the river for thousands of years.
Another factor that may have helped the salmon is the increase in the number of river herring, a small fish that also migrates between freshwater and saltwater. River herring are a key food source for many animals, including seals and striped bass, which are known to prey on salmon smolts, or young fish, as they make their way to the ocean.
“The more river herring there are, the less likely that a predator will eat a salmon smolt,” said Jeff Reardon, Maine brook trout project director for Trout Unlimited, a conservation organization that advocates for coldwater fisheries.
River herring also provide nutrients and organic matter to the river system, which benefits other species, including insects, amphibians and birds.
The Atlantic salmon is listed as endangered under the U.S. Endangered Species Act, and faces threats from climate change, aquaculture and illegal fishing. The species is considered a sentinel of environmental health, as it requires clean water, cool temperatures and diverse habitats to survive.
Relevant articles:
- More wild Atlantic salmon found in U.S. rivers than any time in the past decade, officials say, Boston.com, September 6, 2023
- Maine’s wild Atlantic salmon have their best year in a decade, Bangor Daily News, September 7, 2023
- Atlantic salmon return to Penobscot River in record numbers, The Portland Press Herald, September 8, 2023
- How Maine is working to save its endangered Atlantic salmon, National Geographic, September 9, 2023