Atlantic salmon are an iconic species of the Northeast. They once returned by the hundreds of thousands to most major rivers along the northeastern United States, but now only return in small numbers to rivers in central and eastern Maine (Androscoggin to Dennys).
In the 1900s, Atlantic salmon from Maine were so highly valued that, for more than 80 years, the first one caught in the Penobscot River each spring was presented to the U.S. president. The last presidential salmon was caught in May 1992, because there are now too few adult salmon to sacrifice even one.
Atlantic salmon once supported lucrative commercial and recreational fisheries in New England. They were of great cultural and historical importance to Native American tribes in Maine, as well as a source of food. If this iconic species goes extinct, the services it once provided to the American and Native American people will be lost.
The GOM DPS of anadromous Atlantic salmon was initially listed as an endangered species in 2000. A subsequent rule issued by U.S. Fish and Wildlife Service (USFWS) and NOAA in 2009 expanded the geographic range for the GOM DPS to include the Penobscot, Kennebec, and Androscoggin Rivers.
Because of the rapid decline and dire status of the Gulf of Maine DPS, we and our partners have made it a priority to stabilize and prevent extinction of this iconic species.
Where Gulf of Maine Atlantic Salmon Live
Young salmon spend 2 to 3 years in the rivers and streams of Maine, then undergo physical changes to prepare them for life in the ocean. Once Gulf of Maine Atlantic salmon leave Maine streams and rivers, they migrate to the ocean. Some salmon return to Maine after their first winter at sea, but most spend a second year feeding in the Labrador Sea off the southwest coast of Greenland. Most Gulf of Maine salmon return to rivers in Maine after two winters at sea.
Population Status
The Gulf of Maine population of Atlantic salmon has declined significantly since the late 19th century. Historically, dams, overfishing, and pollution led to large declines in salmon abundance. Improvements in water quality and stocking from hatcheries helped rebuild populations to nearly 5,000 adults by 1985, but in the early 1990s there was a substantial decrease in marine survival that contributed to a significant population decline. As a result, the average number of salmon returning to GOM rivers annually is only around 1,200.
Habitat
Atlantic salmon habitat requirements change throughout their lives. Adult salmon spawn in rivers and lay their eggs in gravel nests. Once salmon eggs hatch into fry, the fry hide from predators in the spaces between gravel. The fry emerge from the gravel after a few months of growth and enter the parr stage. Most parr feed and develop in the river for two to three years before undergoing smoltification, the process in which parr go through physiological changes in order to transition from a freshwater environment to a saltwater marine environment.
Throughout their lives, Atlantic salmon require the following habitats:
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Parr habitat, often called “nursery habitat,” refers to a usually shallow stream area where the water breaks over rocks or gravel and flows quickly. Parr will also congregate around the mouths of small tributaries.
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Smolt habitat refers to unobstructed riverine and estuarine habitats that allow salmon to physiologically transform to a marine life stage.
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Marine habitat refers to habitat that Atlantic salmon migrate to after leaving rivers, where they feed heavily and grow rapidly. Marine habitat must be disease-free, provide food resources, and have good water quality for salmon to survive.
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Adult spawning habitat refers to habitat with a gravel bottom where adults can dig nests. Spawning habitats must have diverse pools, riffles, and runs because adults construct nests in locations with plenty of dissolved oxygen.
Threats
Dams limit or block salmon access to important habitats in Maine. More than 90 percent of Maine’s rivers and streams are affected by dams, which directly kill or injure a significant number of Atlantic salmon on upstream and downstream migrations. Dams also harm important habitats by flooding free-flowing rivers, reducing water quality, and changing fish communities. Finally, dams worsen the effects of climate change by limiting Atlantic salmon’s access to cool-water habitats in higher elevation areas in Maine. Of the more than 400 dams along rivers and streams that support wild Atlantic salmon, only 75 have fishways, a structure that allows fish to swim around dams to reach their spawning grounds.
Gulf of Maine DPS salmon survival in the ocean has decreased over the last 25 years. This means that an increasing number of salmon die in the ocean before they can return to Maine to spawn. Many Atlantic salmon die in the ocean due to predation, starvation, diseases and parasites, and changing ocean conditions. Marine survival is poor throughout the Atlantic Ocean and is affected by both nearshore and open ocean survival rates. This ongoing and significant threat has pushed populations of Atlantic salmon in the United States closer to extinction. The North Atlantic Salmon Conservation Organization leads international efforts to control and better manage foreign fisheries to reduce their impacts on Atlantic salmon born in the United States. Not all causes of low ocean survival are well-known. Threats like climate and ocean changes, plus shifts in predator and prey abundance and distribution, appear to affect salmon survival at sea.
Species Recovery
To work toward recovery of these fish, NOAA Fisheries and USFWS worked with scientists and stakeholders to develop a recovery plan, which was finalized in February 2019. The recovery plan (PDF, 64 pages) builds upon scientific studies and other observations and information sources to identify gaps in our knowledge and the research needed to fill those gaps. The recovery plan also identifies specific criteria that will signal the recovery of the species.
Primary threats with the potential to limit recovery of the Gulf of Maine DPS of Atlantic salmon include:
- Dams and road stream crossings
- Climate change
- Low marine survival
- Loss of genetic diversity
Additionally, the recovery plan identifies numerous secondary threats that, when combined, significantly affect the species chance of survival and recovery. They include:
- Reduced freshwater habitat complexity
- High catch rates in international fisheries
- Reduced instream flow
- Reduced water quality
- Disease
- Predation
- Depleted diadromous fish communities
- Artificial propagation
- Aquaculture
- Competition with nonnative fish species
We work closely with the Penobscot Indian Nation, the U.S. Fish and Wildlife Service, and the Maine Department of Marine Resources to manage Atlantic salmon cooperatively under the Collaborative Management Strategy for the Gulf of Maine DPS Atlantic Salmon Recovery Program.
Species in the Spotlight Priority Actions
The Species in the Spotlight 2021-2025 Priority Action Plan for the Gulf of Maine DPS builds on the recovery plan and the 2016-2020 Priority Action Plan and details the focused efforts that are needed over the next 5 years. These actions are:
- Reconnect Gulf of Maine with headwater streams
- Improve habitat productivity to increase the number of salmon smolts entering the ocean
- Increase understanding of and ability to improve marine survival
In the first five years of Species in the Spotlight, we have taken important steps toward stabilizing this species and preventing its further decline. Our accomplishments have included activities in several areas:
Fish Passage
- Worked with dam owners to make dams safer for migrating salmon
- Five new fishways planned at hydro dams since 2015
Habitat Connections
- 70 aquatic connectivity projects completed in 2018-2019
- Improved access to approximately 250 miles of streams and rivers
Reduce Mortality at Sea
- Negotiated 15 mt catch reduction at West Greenland for 2018-2020, as well as an improved licensing and catch monitoring program
- Continue work with North Atlantic Salmon Conservation Organization
Satellite Tagging to Study Migrations
- Satellite tag project to better understand ocean habitat use and migratory patterns
