Transcript Fish

Anadromous Fish of the Bear Creek Watershed
The Bear Creek Watershed Virtual Tours
were created with funds provided by the
Bear Creek Watershed Education Partners
through a grant from the
Oregon Watershed Enhancement Board
with additional funding from Oregon Trout’s Healthy Waters Institute.
THANKS TO:
•Aaron Maxwell for permission to use his presentation
What are anadromous fish?
Fish that spend part of their life cycle in
freshwater habitats and ocean habitats.
Salmon, steelhead trout, and lamprey are
the anadromous fish species in the Bear
Creek watershed. These fish spend much
of their life in the ocean, but must return
to the freshwater streams they were born
in to reproduce.
Bear Creek:
Your Backyard, a Salmon’s Home
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44 km long
204 km upstream from
the Pacific Ocean
Tributary to the Rogue
River
Mediterranean climate
with an average rain
fall of 50 cm
Dry summers, wet
winters
Nearly 180,000 people
living in Jackson Co. =
one of the most
densely populated
watersheds in OR
What Are the Five Species of Pacific
Northwest Salmon?
largest
Coho (Silver)
Up to 15 lbs.
Chinook (King)
30 lbs, max size 100 lbs!
Chum (Dog)
7- 10 lbs.
Sockeye (Red)
7 lbs.
Pink (Humpback)
2-5 lbs.
smallest
What Are the Two Species of Salmon
found in Bear Creek?
Chinook (King)
30 lbs, max size 100 lbs!
Coho (Silver)
Up to 15 lbs.
Salmon Are Anadromous
An anadromous fish is one that spends part of its
life in fresh and salt water.
Fresh Water
Salt Water
(lakes, streams)
Spawning
Lay eggs
Immature life stages
(Ocean)
Grow and mature
female Chinook
When salmon enter the salt water, their gills, scales, and
blood change to survive in the salt water!
Can You Think of Any Other Anadromous
Species Found in Bear Creek?
Chinook (King)
30 lbs, max size 100 lbs!
Coho (Silver)
Up to 15 lbs.
Can You Think of Any Other Anadromous
Species Found in Bear Creek?
Chinook (King)
30 lbs, max size 100 lbs!
Coho (Silver)
Up to 15 lbs.
Extra Credit!!
What is a non-salmonid
anadromous species also
found in Bear Creek.?
(stay tuned for the answer)
Steelhead (Rainbow)
8 lbs, max size 40 lbs
Do You Know the Difference?
Source: http://www.pac.dfo-mpo.gc.ca/ops/fm/Salmon/salmonid.htm
A Look Inside the Mouth
Source: http://www.pac.dfo-mpo.gc.ca/ops/fm/Salmon/salmonid.htm
Salmon Lifecycle
Stage 1- Eggs
The female salmon lays her
eggs in a nest called a redd.
Redds are found in gravel
beds in freshwater streams.
Stage 2 – Emergence
The young that hatch from
eggs are called alevins. They
have a sac containing protein,
sugar, minerals and vitamins
which disappears as they
grow older.
Alevins with Food Sac
Stage 2 – Emergence
When do Salmonids In Bear Cr. Emerge?
Chinook, Coho, and Steelhead eggs begin
hatching in late winter.
Alevins stay hidden in the spawning gravel
until the are developed enough to move and
feed in calmer waters in the early spring.
Often observed in pools along Bear Cr.
www.blevinsphoto.com/ trout.htm
Stage 3 – Freshwater Rearing
Once they have consumed
the food sac, juveniles
called fry, emerge from the
stream-bed and feed on
aquatic insects.
Some salmon species head
immediately for the ocean,
some stay in fresh water
for up to 3 years.
Notice the bars called parr marks, which
help the parr camouflage in fresh water
streams.
During their trip to the
ocean they undergo the
changes to help them live
in salt water, this is called
smoltification.
Stage 3 – Freshwater Rearing
Steelhead fry
Rotary screw trap used to catch out-migrating fry
Stage 3 – Freshwater Rearing
How long do they stay?
Steelhead- May stay in Bear Cr.
and tributaries for 1, 2, 3, or
even 4 years before leaving.
Chinook- Begin leaving Bear Cr.
in the early spring and generally
swim directly to the estuary.
Coho- Also leave Bear Cr. in the
spring, but will stay within the
Rogue River watershed for up
to 2 years before migrating out
to sea.
Extra Credit!!!
So what’s the difference between rainbow and steelhead?
The Difference?
Steelhead
Rainbow
Steelhead
Rainbow and steelhead are genetically identical. However, rainbow
are not anadromous. Rainbow live their entire lives in freshwater
and are therefore much smaller as reproductive adults and do not
turn silver.
Stage 4 – Estuary Rearing
Smolts transform into ocean fish in estuaries. Their scales, gills
and blood change to survive in salt water.
They must avoid Herons, Kingfishers, and other fish in the
estuary! Where is the estuary that salmon from Bear Cr. use?
Notice the smolt no longer has body stripes. Shiny fish
are better camouflaged in the ocean.
Stage 5 – Ocean Migration and
Growth
Smolts migrate to the
Pacific Ocean where
they grow to maturity
In the ocean, they
grow to large sizes, the
Chinook once reached
over 100 lbs.
These sleek fish must
survive orca, seal, sea
lion, and fisherman
predation.
Stage 6 – Spawning Migration
After spending time in the
ocean, salmon migrate back to
the exact stream in which
they were born.
How do they know where
to go?
Smell and taste = olfaction
Stage 7 – Spawning
Spawning occurs in
the same stream in
which the salmon
hatched.
Females select redd
sites and deposit
eggs.
At the same time, a
male fertilizes them,
expelling his milt
onto the eggs.
When and Where do Salmon Spawn in
Bear Creek?
Winter Steelhead- Adults
enter Bear Cr. in
December- May.
Spawn in the upper
portions of the mainstem of Bear Cr. and
tributaries such as Neil,
Wagner, and Walker
Creeks. North
Mountain Park is a good
place to see spawning
steelhead.
When and Where do Salmon Spawn in
Bear Creek?
Fall Chinook- Fall Chinook
enter Bear Cr. in SeptemberNovember and spawn
shortly thereafter.
Despite being the largest fish
in Bear Cr., they prefer to
stay in the larger waters and
do not migrate upstream as
far as steelhead or coho.
You can even see spawning
Chinook behind the mall in
Medford!
When and Where do Salmon Spawn in
Bear Creek?
Coho- Coho enter Bear Cr.
usually in January and February.
They spawn almost immediately
after reaching suitable habitat.
Very few coho remain, in fact
they are listed as Threatened
under the ESA. You may have
seen coho spawning in Ashland
near Lithia Park this year.
Generally coho prefer smaller
streams for spawning than do
Chinook, but don’t utilize the
tribs as much as Steelhead.
They require pea-size gravel for
spawning.
Stage 8 – Nutrient Recycling
After spawning, the adult
salmon die. At this point the
decomposing bodies provide
nutrients from the sea to the
stream system. This is critical
to the health of streams and
rivers, feeding not only other
animals, but also plants and
even juvenile salmon
themselves!
Decomposing salmon
During the winter you can
smell salmon carcasses along
the banks of Bear Creek
Extra Credit: What is another non-salmonid,
anadromous species found in Bear Creek?
Answer: Pacific Lamprey
A Little about Pacific Lamprey
(An important and interesting native fish)
•Lamprey hatch from redds similar to salmon in Bear
Creek.
•Juveniles called ammocetes are blind, filter feeders that
embed themselves in sandy river bottoms for up to 7
years.
•Ammocetes then develop eyes and gills and migrate
out to sea.
•Upon reaching the ocean they parasitize other fish and
marine mammals by attaching themselves with suctionlike mouths.
•Once fully grown and mature they release from their
host, swim back to Bear Creek and spawn in the early
spring.
Other Cool Native Fish
Cutthroat Trout- a salmonid species found
high in the headwaters of Bear Cr. Common
in upper Neil Cr. Bear Cr. probably had
anadromous cutthroat at one time.
Reticulate Sculpin- a benthic fish
found in many areas in Bear Cr. This
relatively small fish builds egg nests under
rocks, which the male readily defends. Prefers
riffle habitat
Klamath Smallscale Sucker- bottom feeding fish
that likes slow moving water. Moves into Bear
Cr. from the Rogue to breed.
Pictured is a Modoc sucker
Threats to Fish Survival
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Temperature-most salmon cannot
tolerate temperatures above 60°F.
High temperatures means low
dissolved oxygen. Bear Cr. often
exceeds this threshold in the
summer. Causes include water
withdrawals, loss of riparian shade,
loss of hyporheic flows, warm water
inputs, dams that slow and warm the
water…
Loss of Habitat- Bear Cr. has been
channelized over the years thereby
reducing the complex habitat and
spawning gravels required by salmon.
Different life stages require different
habitat.
Clean spawning gravel
Can you think of examples of good habitat in Bear Creek?
Poor habitat
Good complex habitat
Threats to Fish Survival
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Urban and agricultural pollutionmany of the chemicals and nutrients
we use enter Bear Creek untreated
and harm fish.
Poor forest practices- Removing trees
near Bear Creek and clear-cutting
steep slopes near headwater
tributaries increase the amount of
sediment which smothers developing
eggs.
Dams and diversions- Dams,
irrigation diversions, and even road
culverts may prevent fish from
making it to suitable spawning
habitat. Increased water velocity by
culverts may also impede certain
species of fish.
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Are you poisoning salmon?
Removal of riparian
vegetation
Threats to Fish Survival
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Smallmouth bass
Brown bullhead catfish
Bluegill
Introduced Species- many species
like bass, sunfish, and catfish may
be fun to catch, but actually
compete with, eat, and harm
native fish and amphibian species.
Bullfrogs, voracious non-natives,
don’t make matters any better.
Where do you often find introduced
species of fish?
Do those places look like good
salmon habitat?
How does temperature factor?
Bullfrog tadpole
Where are the majority of fish
barriers located?
Which barriers do you think
have the largest impact on
fish?
Can you name any barriers
fish might encounter on the
Rogue River?
Summary
•There are many species of fish
that remain in Bear Creek.
•Because of habitat degradation
many of these species, including
salmon and steelhead, are
threatened with local extinction.
•There is hope. Celebrate native
fish by teaching others about
their backyard and by thinking
about what you can do to
improve a salmon’s home.
Coho female
Disclaimer and creditsPhotos provided by Jason Bauer, Carson, and the internet.
GIS contributors include Dick Best, Chris Zanger and Terri Eubanks.
Technical info was derived from Bear Creek assessment provided by the Rogue Valley
Council of Governments, and other sources.
Thank You All