Species in the Spotlight

Gulf of Maine Distinct Population Segment of Atlantic Salmon

The Gulf of Maine DPS of Atlantic salmon is one of NOAA Fisheries’ Species in the Spotlight. This initiative is a concerted, agency-wide effort to spotlight and save the most at-risk marine species.

Species in the Spotlight logo.

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 Maine.  

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. Before this, they were of great cultural and historical importance to Native American tribes in Maine. Atlantic salmon supported important fisheries that were a main food source for the tribes. If this iconic species goes extinct, the services it once provided to the American and Native American people will be lost.  

NOAA Fisheries listed the Gulf of Maine DPS as endangered under the Endangered Species Act in 2000. We then extended ESA protection in 2009 to include more Atlantic salmon in other rivers in Maine. Because of the Gulf of Maine DPS’s rapid decline and dire status, NOAA Fisheries and its partners have made it a priority to stabilize and prevent extinction of this iconic species.

Where Gulf of Maine 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 the freshwaters of Maine rivers, they migrate to Newfoundland and Labrador. They spend their first winter at sea south of Greenland.

After the first winter at sea, a few salmon return to Maine. However, most salmon spend a second year at sea, where they live and feed off the southwest coast of Greenland. Some Maine salmon are also found in waters along the Labrador coast. After a second winter in the Labrador Sea, most Gulf of Maine salmon return to rivers in Maine.  

Population Status

The Gulf of Maine population 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 many salmon started to die in the ocean, resulting in a significant population decline. Less than 1,000 fish now return to Maine’s rivers every year.  

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. Throughout their lives, Atlantic salmon require the following habitats:  

  • 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.

  • Smolt habitat: refers to unobstructed riverine and estuarine habitats that allow salmon to physiologically transform to a marine life stage.

  • Marine habitat: refers to habitat that Atlantic salmon migrate to after leaving rivers, where they feed heavily and grow rapidly. Marine habit must be disease-free, provide food resources, and have good water quality for salmon to survive.

  • Adult spawning habitat: refers to habitat with an unembedded, 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’s 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.  

Recovery

To work toward recovery of these fish, NOAA Fisheries formed a recovery team of scientists and stakeholders to help develop a recovery plan, which was finalized in March 2016. 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 these animals.

Threats with the potential to limit recovery of the Gulf of Maine DPS of Atlantic salmon include:

  • Dams and road crossings.

  • Inadequate regulation of dams.

  • Low survival rates in the ocean.

  • Loss of habitat features due to human activity.

  • High catch rates in international fisheries.

  • Reduced water quantity.

  • Reduced water quality.

  • Fish harvest.

  • Disease.

  • Increased number of predators.

  • Decreased populations of interconnected fish species.

  • Artificial propagation.

  • Aquaculture.

  • Competition with other fish species.

  • Climate change.

In developing the draft recovery plan, NOAA Fisheries aims to provide recovery goals and objectives toward which all stakeholders can work together. 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 Atlantic salmon framework.

Learn more about the Atlantic salmon framework

In 2016, we completed a Species in the Spotlight 5-year action plan for the Gulf of Maine DPS (PDF, 17 pages) that builds on the recovery plan and details the focused efforts that are needed over the next 5 years.