| Pacific
Salmon Spawn - The Return of the Salmon
British Columbia
is home to five species of salmon, all in the genus Oncorhynchus.
Their life cycles tell a tale that has always captivated people,
and we are witness to parts of the cycle in the streams and rivers
around us.
Although each
of the five species has a slightly different life cycle, the basic
story is much the same. The young salmon spend the first part of
their lives in the streams where they hatched, moving to salt water
some months later. They then spend a period of several years growing
to adulthood in the food-rich waters of the Pacific Ocean. When
their time comes, they are called back to the streams where they
were born.
Chinook
Salmon being carefully released to
continue on to its spawning grounds
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Their voyage
home is nothing less than epic, across thousands of kilometres of
ocean. Guided largely by smell, they return to their natal streams,
some along the coast, and some far inland along major river systems.
Their bodies now brightly coloured and distorted as they prepare
for spawning, they battle their way past riffles and chutes, until
they arrive at a familiar stretch of riverbed.
Here, the males
battle for the right to fertilize the females, and the females batter
their bodies as they dig redds in the gravel in preparation for
egg-laying. When they are spent, their carcasses lie rotting along
the riverbanks, providing food for scavenging birds and mammals,
and cycling nutrients back into the ecosystem. In time, the eggs
hatch, and a new generation of tiny salmon begins the cycle again.
The Spring or
Chinook Salmon, O. tschawytscha, is the largest of the five species,
with some fish reaching a weight of 50 kilograms. The declining
Coho Salmon, O. kisutch, is more associated with smaller streams.
Sockeye O. nerka, spend part of their lives in freshwater lakes,
and have become famous for their return to the Adams River in the
B.C. interior. Pink Salmon, O. gorbuscha, have a two-year life cycle
that is so consistent that "even-year" and "odd-year"
runs are recognized. Chum Salmon, O. keta, is widely distributed,
and easily seen at some spawning streams.
Also now included
in this genus are the Steelhead Trout, O. mykiss, and the Coastal
Cutthroat Trout, O. clarki. Both are sea-run fish, but are not as
numerous as their cousins.
Spent
Chum Salmon in Goldstream Park
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The salmon spawning
runs also attract other wildlife. Bears gather at more remote rivers
to fatten up for their winter sleep.
Hundreds of Bald Eagles are drawn
to Goldstream, while a thousand may show up at the Nimpkish River,
north of Campbell River on Vancouver Island. Gulls gather by the
thousands, too, gorging on the spent fish. Goldstream is well-known
for a small-stream specialist, the American Dipper (Cinclus mexicanus).
This dumpy little gray bird prefers fast moving streams, where it
dips, swims, and even walks on the bottom, as it feeds on insects
and salmon eggs.
There are excellent
opportunities to watch salmon as they make their voyages upstream.
At Stamp River Provincial
Park near Port Alberni,
fish can be seen jumping the cataract there. Goldstream
Provincial Park, near Victoria,
has an excellent interpretive program during the Chum Salmon run
late in the fall. For an up-close look at a hatchery program, visit
the Freshwater Ecocentre in Duncan.
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