Maurice
Coulter-Boisvert, Community Advisor, DFO has taken one end of
the net across the river
and he is starting to lead it
downstream.
John Martin and Dave Belgrove beat water to scare fish upstream
and into the net.
Coho with jaws (not gills) tangled in the 4 inch mesh net.
The small mesh net is used
to minimize possibilities for fatalities
from to gill damage. The net is cut to easily remove any fish caught by the gills.
Removing a large catch of Coho from net.
Scott Duchame and Sandy Lamberton move a female Coho from the
net into a live bag to be
carried to the trailer.
A total catch of between 100 and 120 adult salmon is required to stock the hatchery.
Rick LaJambe and Tony Matahlija show a 12 kg (25 lb +) Chinook
that was released.
Maurice removes a male and a female Chum from the net.
These fish will be spawned to
stock
DFO's school programs in the Lower Mainland.
Volunteers float and carry live bags of Coho back to the trailer
for transport
to the hatchery for "ripening".
Maurice and Scott compare and sort male and female Coho into
fish tanks at
the hatchery where they "ripen" to maturity for spawning.
A large, but too silvery and still immature, 5.5kg (12 lb.) male
Coho.
Sandy displays a very large 7 kg (15.5 lb.) mature male.
Coquitlam Coho do not come
much larger than this.
The bright red colouring usually indicates a mature fish.
Maurice checks a large male Coho for maturity which is confirmed
when milt can be expressed.
A large female Coho is checked for maturity which is confirmed
when eggs can be
expressed.
The dark, almost black, colouring is indicative of a mature fish
that is ready to spawn.
A male's milt, which contains sperm, is expressed and
collected for fertilizing eggs.
Females are killed, bled and dried in preparation for taking
their eggs. Water or blood
on the eggs
prior to fertilization significantly decreases fertilization
success rates.
The side of the belly is opened and the eggs are stripped into a
container.
After the
container of eggs is weighed, a sample of eggs is counted and
weighed to determine the
average weight per
egg. The average weight per egg is divided into the
weight of the eggs from
the container to calculate the total number of
eggs taken from each
female and, on completion
of broodstocking activities, to establish the total number of
eggs that are
to be incubated in the hatchery this year. The total
number of eggs is not permitted to exceed the limit stipulated in the
annual hatchery license issued by DFO.
The fertilization
process commences by mixing a small amount of the milt taken from each of several males into a bucket
that contains
the eggs from one female. This simulates conditions in stream spawning
areas which provide genetic diversity in the salmon stock.
Fertilization occurs almost instantaneously when water is added
to the eggs/milt mix.
Fertilized eggs turn brighter
in colour and unfertilized (dead) eggs turn white.
Fertilized eggs are drained, water rinsed in a colander and
disinfected for ten minutes
in a solution of buffered iodine fungicide.
Treated
eggs are placed in Heath Trays, dead (white) eggs are
carefully removed (and
counted), the tray is placed
in a stack of trays and left in flowing water to incubate in darkness. In nature the eggs
would be buried
in the gravel of the streambed at this stage.
Eyed Coho eggs
in late December. The black dots are embryonic eyes
forming in the eggs.
The eyed eggs are "shocked" by pouring them from their tray
from a height of about 250
mm (10 in.) into about 75 mm (3 inches) of water in a
container which kills the weakest eggs and reduces possibilities for fungus
infections and diseases for the balance of the incubation process. After eyes appear, the
Incubating eggs are checked regularly for indications of fungus. Dead eggs are removed, counted
and recorded and the number of live eggs in the hatchery is always known.
Eyes appear in Coho eggs after about
220 ATUs. Hatching occurs after about 460 ATUs. While the Chinook eggs that were
received from Chilliwack hatchery in early November are a bit
larger, they were similar in
appearance to the Coho eggs shown in this photo.
Chinook eggs eye at about
250 ATUs and hatch at about 520 ATUs.
Incubation and hatching durations
are different for each salmon species. The durations depend on water temperatures and are
determined by Accumulated Thermal Units (ATUs). A
Thermal Unit is defined as
one degree Celsius of temperature for a duration of one
day. At an average water
temperature of 6 degrees, Coho eggs will be eyed in 37 days
and hatched into alevins in
77 days from fertilization.
Chinook alevins
(approx. 25mm (1 Inch) long in late December recently hatched
from imported eyed eggs after
about 520 ATUs (9 weeks) at our hatchery. At this stage
the alevins in the tray are
swimming quite actively, as they would be in the voids in a
redd (nest) in streambed
gravel in nature. When a tray is opened, they try to
avoid light by moving under
other alevins to stay close to the bottom of the tray. Treatments are applied if disease or fungus is detected. The alevins live
on the contents of their orange egg sacs until they are ready to leave their tray as
free-swimming fry or, in nature, are ready to swim out of the streambed gravel.
Chinook alevins in late January with egg sacs about half
absorbed and parr marks (large
oval spots on their sides )
forming about 5 weeks prior to becoming free swimming fry that will be transferred to a rearing
trough for feeding.
Coho eggs hatching in late January. This photo shows fully
developed embryos in some eggs, alevins partially out
of some eggs, newly hatched alevins and empty egg shells.
Coho eggs starting to hatch in late January. Two alevins
are free, the tail of
another is out of its egg
and the full term embryos are clearly visible in the other eggs.
Coho alevins in mid-February about 10 days after hatching.
In a streambed environment,
these alevins would still
be buried in their redd (nest) in the gravel.
Coho alevins 3 weeks after hatching.
Normal and abnormal Coho alevins. In nature, such
abnormalities are few and normal.
The "siamese" alevin will die
soon after the shared egg sac is absorbed because it will not be able to compete for or
digest food efficiently.
Also note the size difference.
Approximately 4,000 Chinook fry are transferred in their
Heath Tray incubation basket
to a rearing trough in
late February approximately 10 weeks
after hatching.
Close up of Chinook fry being transferred to a rearing trough in
late February. These
fry are about 35 mm (1.5 inches) long,
their egg sacs are fully absorbed and their distinctive parr marks are showing clearly
on their sides. Parr marks are different
in sizes, shapes and
patterns for each salmon species.
These Chinook
fry are slowly starting to leave their incubation basket in the rearing trough. They will rise
to the water surface to take a "gulp" of air, which will activate their swim bladders,
before they slowly start to feed on "fry food" (small granules of a commercially prepared dry
mix of ground fish, krill and other nutrients). The swim bladders permit the fish to
change depths. The food is sprinkled by hand or by auto-feeder belt onto the water
surface. After a day or two their feeding habits become aggressive and they grow
rapidly. At this stage in a stream environment, the fry
swim out of the gravel and
start to feed on small insects and aquatic life forms.
Growth in the wild is more
difficult and slower than it is in a hatchery.
Chinook fry after being fed for four
weeks in a rearing trough.
Coho alevins with egg sacs about half absorbed in mid-March
about 4 weeks before becoming
fry. At this stage
in a natural environment, the alevins are still buried in the streambed gravel.
Coho alevins showing the remnants of their egg sacs almost
absorbed. At 127 days from
fertilization, these fish will soon
be ready for transfer from their incubation tray to a rearing trough for feeding.
Coho fry early in April 35 mm (1.25 inches) long and 134 days
from egg fertilization showing
orange lines on their bellies,
where egg sacs have been absorbed, and distinctive parr marks on their sides. These fish are
ready for transfer
to a rearing trough to be fed with fry food.
Coho fry in the
rearing trough, early in April, leaving their incubation tray
to swim to the surface for
air to activate their swim
bladders. They will soon start feeding on the fry food granules that are
floating on the water surface. All of our Coho fry production is reared for approximately
three months in the trough.
At this stage in a stream
environment, these fish would be swimming out of the gravel to
feed aggressively on small
insect and aquatic life forms. After avoiding predators
and growing for another 14
to 15 months the survivors will migrate downstream to the
ocean.
We retain approximately 23,000 Coho
fry for clipping and rearing for the 14 to 15 months required for them to mature into smolts
that are ready to go to sea. The balance of the Coho fry (50,000 to 75,000) are released in
May into Coquitlam River and tributary streams habitats.
Chinook parr in
mid-April, 50 to 65 mm (2.0 to 2.5 inches) long with parr
marks fading, as they
start to become smolts and change to their green back, silver
sides ocean colours in
preparation for migrating to the ocean. The hatching and
development progression for
young salmon of all species is from eggs, to alevins, to fry,
to juveniles, to parr and to
smolts which are ready to journey downstream to the ocean.
Dave releasing
Chinook smolts into the Coquitlam River in early June.
These smolts will spend
very little time in the river. They
seem to know that food rich ocean habitat is just a short distance downstream. We
hope that between 3 and 5 percent
of our smolt production
will return to the river in 3 to 5 years weighing between 3
and 20 kg (7 and 44
lbs).
Mike and Rebecca Ciccone help goddaughter Natalie release
Chinook smolts at the
hatchery on an evening in May.
Many families participate in and enjoy our fish releases.
Coho parr in
process of maturing to a smolt. Note the faded parr
marks and the growing prominence of silver colouring.
Coho smolt in
June "silvered up" and ready for release to go to sea. This fish is from the 23,000 parr that
were clipped 11 months
earlier. It has been cared for in our hatchery for about 18 months from eggs to
smolt stage. These fish have fed very aggressively
and grown to lengths ranging from 115 to 180 mm (4.5 to 7.0
inches). Most of the survivors will return at age 3 after
spending
about 18 months in the ocean. The very large coho shown in
earlier photos are probably 4 years old.
Brendan Fletcher,
Ric Locke and son, Jet, release Coho smolts into the river in June. After
about 18 months
in the ocean, between 5 to 7
percent of these fish will
return to the Coquitlam River in November and December
as adults, spawn, die, decompose and provide nutrients that
will support small aquatic life forms to feed
emerging fry and complete their life cycle.
In late July, Cameron Fletcher places Coho juveniles in an
anaesthetic solution for 20
to 30 seconds to sedate them for
clipping. As with hospital operations for people, the fish are not fed the day
before or on the day that they are clipped.
Coho juveniles 45 to 65 mm (1.75 to 2.50 inches) long, in a
basin on the clipping table,
sedated and ready for clipping.
Note the bubbles which indicate that the fish are breathing and that they will soon recover
from the anaesthesia.
Volunteers clipping Coho in late July. This group clips
approximately 7,000 fish per
hour. Note that anaesthetized fish
are being distributed from the small net into the basins in front of the clipping
stations. Clipping operations are busy
and popular with families
and friends.
Closeup of
clipping operation with the fin still on the scissors. The
specs in the basin are
removed fins. Fresh water, which flows
in the gutter at the edge of the table, carries clipped fish into a bucket where
they recover very quickly from the anaesthetic.
Full buckets of recovered fish are returned to the hatchery
fish tanks for observation. The mortality rate from the clipping
process is very low (usually less than 1 per 2,000
fish). The clipped
Coho will be fed and cared for at the hatchery
for 11 more months before they become silvered smolts that are ready to travel to the
ocean.
Port Coquitlam Rivers and Trails
Festival
PCDHFC hatchery
volunteers entertain large numbers of families and kids of all ages at this annual event in
late September
by providing 2,000 to 3,000 young Coho juveniles for them to carry in water filled
plastic bags and release into
Coquitlam tributary
pond habitat at Lions Park in Port Coquitlam. For many
youngsters, and even for
some adults,
this is their first close look at a live salmon. Rain or
shine, a great time is
enjoyed by all !
THIS IS NOT THE END
While "Rivers
Day" is usually our last group event before receiving Chinook
eggs and the start of
broodstock activities in November, it is not in any way an end
for our hatchery operations.
The 23,000 t0 25,000 clipped Coho require daily care,
equipment has to be prepared
for the start of new broods in November and
hatchery maintenance and capital improvement projects have to be completed. The
volunteers and DFO personnel continue on their regular schedule "hatchery day"
duties. Their efforts have improved, and we hope that they will continue to improve,
Coquitlam River salmon runs. Their ongoing participation
in preserving and enhancing
these salmon stocks is very much appreciated. PCDHFC has actively supported
conservation efforts in our communities since 1956 and we are looking forward to continuing our
involvements through Grist Goeson Memorial Hatchery salmon enhancement and other activities
for many more years.
If you are
interested in participating in any of our hatchery activities
please contact
Norm Fletcher (Telephone:
604-942-0371 Email: nwfletcher@telus.net).
