Atlantic Salmon (Salmo Salar)

Sportfishing One of the best known members of the salmonid family.
Weekend The Atlantic salmon is also known as: grilse, grilt,
fiddler; salmon living only in freshwater are called
Lake Surveys landlocked salmon, ouananiche and grayling; black
salmon, slink, kelt (all for postspawning fish);
Stocking Program Kennebec salmon, and Sebago salmon.


Species Atlantic salmon are native to the North Atlantic
Factsheets Ocean and coastal rivers and can be found on both
sides of the ocean including parts of Russia,
[Image] Portugal, Iceland, and Greenland. In Canada and the
U.S. they can be found from Northern Quebec and
Labrador to the Connecticut River.

Due to overfishing and the destruction of habitat, salmon no longer
can be found in much of its original range and the numbers of fish
have seriously declined. As an example, since the late 1800s, there
have been no salmon in Lake Ontario. Landlocked populations of
Atlantic salmon exist in some lakes of eastern North America,
particularly in Newfoundland, Labrador, and Quebec.

Physical Characteristics

Salmon can vary in colour depending on the water they're in, their
age, and sexual activity. In fact there are so many different physical
looks in the life of a salmon that it can be confusing. What follows
are some of the common colour characteristics.

* Salmon in saltwater: blue, green or brown on the back and silvery
on the sides and belly. On the upper body you can find several
x-shaped black marks or spots.
* Salmon in freshwater: bronze-purple in colour and sometimes with
reddish spots on the head and body.
* Spawning males: these fish develop a hooked lower jaw (kype)
* Salmon finished spawning (kelts): very dark in colour
* Young salmon (parr) in freshwater: 8-11 dark bars on the side
with a red spot between each one
* Young salmon leaving fresh water for the sea (smolts): silvery in
colour and usually about 12-20 cm (5-8 in) long. Atlantic salmon
can be easily confused with both brown trout and rainbow trout.
However there are several characteristics that can help you
distinguish the different species. Rainbow trout have rows of
spots on the tail (caudal) fin that is not found in salmon and
brown trout have a reddish colouring on the adipose fin (the
small fin in front of the tail on top of the body).

Facts on Salmon

The name salar comes from the Latin "salio" which means to leap. The
Atlantic salmon can make leaps 3.7 m (12 ft) high and 5 m (16.3 ft)
long!

Atlantic salmon are mentioned in the Magna Carta.

In the wild, about 1 in 10 young salmon survive to become
smolts and in many rivers fewer than 1 in 25 of those will return to
spawn.

Most grilse are male.

Biologists can "read" the scales of salmon to determine how
old they are, how many years they spent in fresh water, how many years
they spent at sea and at what ages they spawned.

Salmon Sizes

Sea-run salmon can be as big as 1.5 m (59 in) and 36 kg (79
lb) but most are 9 kg (20 lb) or less.

Biggest known fish ever caught in Canada: a 25.1 kg (55 lb)
fish caught in the Grand Cascapedia River, Quebec.

After one winter at sea (grilse): 1.4-2.7 kg (3-6 lb)

After two winters at sea: 2.7-6.8 kg (6-15 lb)

Landlocked Atlantic: 0.9-1.8 kg (2-4 lb). However a 16.1 kg
(35.5 lb) specimen was taken in Sebago Lake, Maine, over 50 years ago.

More Facts on Salmon

Salmon have been reared in hatcheries
for decades to provide smolts for river
stocking programs. Today they are commercially
farmed in large ocean pens, a rapidly growing
industry in Atlantic Canada.

After about 3 years (but anywhere from
2 to 8) in fresh water, salmon parr turn into
smolts and prepare for life in saltwater. In
the spring, these parr become slimmer and turn
silvery. During the spring run-off, as water
temperatures rise, smolts form schools and
migrate downstream at night. It is during this
downstream migration that smolts "learn" or
become imprinted with the characteristics of
their particular river.

At sea salmon are known to travel long
distances. Many salmon from Maritime rivers
travel as far as the western coast of
Greenland where the waters are rich in food.
Here, salmon grow rapidly, feeding on
crustaceans and other fishes such as smelt,
alewives, herring, capelin, mackerel and cod.
Salmon will stay at sea for one or more years.
Salmon that spend only one year at sea are
smaller and called grilse when they return to
fresh water to spawn. At sea, salmon are eaten
hy cod, pollock, swordfish, tuna, and sharks.
Some have been known to live to 11 years.

Natural History

Atlantic salmon spend part of their life feeding and growing during
long migrations in the sea, and then return to reproduce in the fresh
water stream where they hatched. This type of pattern, moving from the
sea to freshwater, is described as being anadromous.

Atlantic salmon that are ready to spawn begin moving up rivers from
spring through fall. These spawning runs are surprisingly consistent
and occur at the same time each year for each river. Salmon
populations are often spoken of as "early run") or "late run". Salmon
travel long distances, as much as 500 km (312 mi) upstream and are
known for their ability to leap small waterfalls and other obstacles.
During this journey, the salmon does not eat, though it rises readily
to an artificial fly. Landlocked salmon living in lakes move up into
tributary streams to spawn.

Spawning occurs during October and November usually in gravel-bottom
at the head of riffles or tail of a pool. The female looks for places
where the water is seeping down into clean gravel.

Spawning occurs in the evening and at night. The female digs a nest
(redd) 15- 35 cm (6-14 in) deep in the gravel by turning on her side,
flipping her tail upward and pulling the gravel up until a hole is
excavated. After the female and male spawn in the redd, the 5-7 mm
eggs are buried with gravel by the female. The whole process is
repeated several times until the female has shed all of her eggs.
Females produce an average of 1500 eggs per kg of body weight (700
eggs/lb). After spawning the adults (now called kelts) usually drop
downstream to rest in a pool.

Contrary to some stories, adults do not die after spawning. Exhausted
and thin, they often return to sea immediately before winter or remain
in the stream until spring.

Some will survive to spawn a second time but few survive to spawn 3 or
more times.

Salmon eggs develop slowly (about 110 days) over the winter while
water flowing through the nest keeps the eggs clean and oxygenated. In
most of our rivers the eggs survive quite well and are protected from
freezing or silt. The eggs hatch in the spring, usually April, and the
young salmon (alevins) remain buried in the gravel for up to 5 weeks
while they absorb the large yolk sac. It's at this stage that many
young fish are lost. Over the winter silt and sand often move into the
nest and can trap the young fish. If they make it through this stage,
the young salmon that emerge are about 2.5 cm (1 in) long in May or
June.

During this freshwater stage before they migrate to sea they are known
as parr. Salmon parr are territorial and feed during the day.

They eat mainly water insects but will also eat other invertebrates
when available. Young salmon usually live in shallow riffle areas
25-65 cm (10-26 in) deep that have gravel, rubble, rock, or boulder
bottoms. Salmon parr may be eaten by many kinds of predators including
trout, eels, other salmon, mergansers, kingfishers, mink, and otter.
During the winter parr stay under rocks on the bottom of the stream.