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Watersheds and Fish Habitat

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It Takes
an Entire Watershed
to Raise a Fish
Watersheds and Fish Habitat
Alaska is blessed with an
abundance of fish and
other aquatic resources
Healthy fish populations depend
on healthy watersheds
Some fish,
like rainbow trout,
depend
on watersheds through
their entire life cycle
Arctic grayling & burbot,
Anadromous Fish in Alaska
• Pacific Salmon
• Rainbow trout
(steelhead) and
Dolly Varden have
both anadromous
and resident forms
• Hooligan
• Sheefish
• Lamprey
• others
• Depend on
watersheds for all
important life
functions
• Use the ocean
only for feeding,
growth and
development
• May spend 40 to
70% of their life
in freshwater
Salmon in Alaska
Genus Oncorhynchus
Species Name Common Name
Other Name
nerka
Sockeye
Red
tshawytscha
Chinook
King
kisutch
Coho
Silver
keta
Chum
Dog
gorbushca
Pink
Humpy
Fish and aquatic resources
are important to Alaskans
We must understand
watersheds and freshwater
fish habitat needs so we
can preserve, protect and
maintain these valuable
resources
Fish need habitat for one
reason:
SURVIVAL
SURVIVAL
• Fish must survive as individuals
• Individuals must survive to maintain
the population
• Populations must survive to maintain
the species
Fish habitat needs for
survival
- Feeding
– Escape
- Overwinter
- Spawning
- Migration
Juvenile and adult fish
have different habitat
needs for survival
And survival is important
during all seasons
Where do fish find their
habitat needs?
• For different
– Species
– Life stages
– Seasons
In a Watershed
What is a WATERSHED?
• A watershed is an entire region
(or “basin”) which drains into a
river or river system
• Usually includes sub-basins
A watershed is like a
community for fish
• People find their
needs in a
community
• Fish find their
habitat needs in a
watershed
Fish and people need food
• People find
food in
• Each fish species
restaurants or prefer different food
grocery stores organisms and the
fish go to where
their food is found
• Young people
like different
foods than
older people • Young fish need
different food than
older fish
Different things happen
during different seasons
• People are more
active during
summer
• Winters may be
dangerous for
people to survive
• Fish are more active
during summer; they eat
more and grow faster
• Winter survival is
difficult for many fish
populations
Reproduction is important
• People go to
special places to
meet friends or
mates
• Different people
have different
ways to meet
friends
• Each fish species
has unique
spawning time,
place and strategy
•
Parts of a watershed are
connected
People move around
a city by roads and
trails
• When passage to
different parts of
a city is disrupted,
people cannot find
what they need
• Fish migrate to
different parts of
a watershed for
different needs
• When passage to
different habitats
in a watershed is
disrupted, fish
become stressed
A watershed is like a city
for fish
• People need:
–
–
–
–
Food
Security
Seasonal activities
Socialization/
Recreation
– Safe passage
• Fish need:
–
–
–
–
–
Food
Security/Escape
Overwinter
Spawning
Safe Passage
Food
• Fish need food to grow
• Bigger, fast growing fish survive better
• Bigger females lay more eggs
Security/Escape
• Fish need safe places to rest
• Fish need places to hide from predators
• Fish need refuge from both floods and
drought
Overwinter
• Cold water slows fish metabolism
• Still waters freeze and are not
available for fish
• Cold, sluggish fish are more
vulnerable to predation and freezing
Anchor Ice over Rocks
Spawning
• Without spawning and reproduction,
a population cannot survive
• Where individual populations cannot
survive, a species cannot exist
Migration/Passage
• Migration corridors
allow access to
different habitats
• Important during all
seasons
• Different species and
different life stages
have different needs
Each fish species finds
their unique habitat needs
for different life stages in
different parts of a
watershed
A watershed includes
components from the
mountains to the sea
•
•
•
•
•
Glaciers
Tributaries
Lakes
Wetlands
Estuaries
Common Denominator:
WATER
• Every aspect of fish habitat
depends on abundant, clean water
• Quantity and quality are both
important
Alaska Watersheds
• 15,000 cataloged anadromous streams in
Alaska (about half the estimated total)
• Some watersheds are only a few sq. mi.
• The Cook Inlet watershed is 47,000 sq. mi.
• The Yukon River watershed is about 300,000
sq. mi.
• About 365,000 miles of waterways in Alaska
• Over a million lakes in Alaska
A watershed is a factory
that makes fish
• Different parts of the factory; i.e.,
habitats, have different functions
• Each part (habitat) depends on the other
parts
• All of the parts work together to produce
a product (fish)
Watershed Fish Factory
• The raw
material is
abundant
clean water
• Energy comes from the
sun and nutrients that
drive the food chain to
produce fish
Nutrients in a watershed
• Minerals leach
from the land
• Organic matter
comes from
streambank
vegetation (i.e.,
“riparian areas”)
• Anadromous fish
are an important
fuel source for
many Alaskan
watershed fish
factories
Anadromous
fish are
 Feed in the ocean &
important
accumulate “marine
in a
nutrients”
watershed
 Some salmon may travel
3,000 miles during their
feeding migration
 Some chinook salmon may
spend five years feeding in
the ocean
Anadromous
fish are
 Carcasses are eaten or decay
to release marine nutrients in
important
the watershed
in a
watershed
 Marine nutrients are in the
food chain, riparian
vegetation, and groundwater
 Some chinook and chum
salmon spawn in the Yukon
River 2,300 miles inland
How Important
is the
Watershed?
• Young anadromous
fish live in the
watershed until they
become smolts and
migrate to the ocean
• Adult anadromous fish
need the watershed to
spawn
• Resident fish species
depend on watershed for
• 1 - 3 (or more) years
their entire life cycle
How Important is the
Watershed?
• Different species
live in different
places and eat
different foods
(e.g., young coho
live in ponds; young
sockeye live in lakes)
• Most growth is in
late summer when
water temperatures
and food abundance
are optimal
How can you help Protect
Fish Habitats in Watersheds
• Learn about fish habitats in watersheds
• Participate in a local watershed group
• Learn about proposed changes and
become involved
• Beware of small, incremental but
cumulative changes
• Work to retain riparian areas
• Contact ADF&G for information about
anadromous streams:
http://www.state.ak.us/adfg/
• Contact ADF&G or other resource agencies
about activities that may affect fish and
wildlife or riparian areas
It takes an Entire,
Healthy Watershed to have
Good Fish Habitat
It Takes an Entire
Watershed to Raise a Fish
Acknowledgements
-
-
Funding was provided by
Conservation and
Reinvestment Act (CARA)
Thanks to Anchorage
Waterways Council, ADF&G
staff, and others who
provided review comments
Thanks to the many people
who contributed photographs
to make this possible
One last thing:
You can obtain a copy of this
PowerPoint file from ADF&G,
Division of Habitat and
Restoration, Anchorage
907-267-2285
Bill Hauser
ADF&G – H&R
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