Wild Atlantic salmon —a natural wonder

Since the last ice age, wild Atlantic salmon have established themselves in more than 2,000 North American and European rivers.

Image

Salmon and the Environment

Atlantic Salmon are great indicators of the overall health of an ecosystem; when an ecosystem is healthy and well-connected, its salmon are typically also healthy. Conversely, when salmon populations are declining, it could be indicative of a change in the ecosystem.

 

Due to their complex migration from rivers to the ocean, salmon are an important species in a variety of ecosystems. Salmon contribute to biodiversity, and play an important role in the food chain in both freshwater and marine environments.

Salmon and People

Atlantic salmon is an important species for many Indigenous communities. Salmon are large fish that can provide sustenance to many families as well as support social, cultural, and economic relationships.

 

When European settlers arrived, salmon became a key part of their diets as well. Angling quickly became an activity that is still enjoyed today by many people who are passionate about salmon

Tigers of the Sea

Wild Atlantic salmon are capable of incredible bursts of speed while hunting. In the ocean, they develop needle-sharp teeth that grab and hold prey. Capable of diving over 900 metres (3,000 feet), wild Atlantic salmon consume deep sea creatures as well as small fish that school closer to the surface. Under the right conditions, a salmon smolt weighing 30 grams leaving freshwater can return two or three years later as an adult weighing more than 25 kilograms (55 pounds).

A Life of Transformation

Atlantic salmon are in the 1% of fish species worldwide that move between freshwater and saltwater environments. To survive, their body changes shape and colour; their gills and organs, like kidneys, also adjust.

A Life of Transformation

For instance, juvenile salmon (parr) have stripes on their flanks to camouflage them, while Atlantic salmon become dark blue with a silver belly to avoid predators in the ocean. Upon returning to freshwater, Atlantic salmon turn bright silver with a lilac sheen for a few days before changing to their standard colour.

A Life of Transformation

Salmon also transform as they prepare for spawning. Sexual features, like the male’s hooked jaw, known as a kype, become prominent. Kelts, also called Black Salmon, spawn in the autumn and stay in their river over the winter. Returning to the ocean, they are skinny, having used all their fat reserves and reabsorbed muscle tissue.

Threats

Atlantic salmon face many natural and man-made threats despite their speed and strength. Predators like striped bass and invasive species such as smallmouth bass can take their toll in freshwater, while industrial pollution, dams, and clear-cutting alter their environment. Climate change impacts salmon survival in freshwater by causing warmer water temperatures as well as severe weather events which can also contribute to habitat alteration.

Threats

Seals, sharks, and other large fish prey on wild Atlantic salmon in estuaries and the open ocean. Open net-pen salmon aquaculture has emerged as a significant threat to wild salmon in areas where the industry is present. Increasingly, climate change is also affecting ocean survival by changing currents and temperatures, altering the food chain, and disrupting prey abundance.

Only a tiny percent of Atlantic salmon survive from egg to adulthood. If a 5-kilogram (11 pounds) female lays 8,000 eggs, on average, two will live long enough to spawn as adults.

Long-Distance Swimmers

Atlantic salmon are one of nature’s greatest navigators. Their migration is a 4,000-kilometer (2,000 nautical miles) round-trip voyage. Guided by the earth’s magnetic fields and an incredible sense of smell, Atlantic salmon return to spawn in their home river, sometimes in the same gravel bed, they hatched from.

Scales like Tree Rings

Like tree rings, Atlantic salmon scales have growth lines, providing rich information about their life history. This information includes how many years they spent in freshwater before heading to sea, how long they stayed in the ocean, and how many times they spawned. DNA analysis reveals which river a salmon was born in and whether there has been any breeding within aquaculture escapes. In 2016, scientists in Newfoundland uncovered widespread introgression from escaped aquaculture salmon using DNA tools.

State of Populations

Read the most recent State of Populations Report below:

Read the full State of the Populations Report

Note: No report was published in 2022 because of covid related data gathering interruptions.

What We Do

Want to know more about what we do? Learn More

Support Us

If you want to leap like salmon, there are ways you can do that! You can support us by subscribing, becoming a member, or donating.

We are waiting for YOU!