Life against the current
The nearshorewaters and estuaries (where fresh and saltwatermix) of the Sound are critical
habitat for salmon as they get ready for theirmigration from their home stream to the ocean andback.
After swimmingback to the same streamwhere theywere born,
each female salmon deposits 2,000 to 4,000 eggs in the gravel of
our region’s rivers and streams. In about 50days, the salmon hatch.
At this point they are called alevin and still live in the gravel. Alevin
get their food from a yolk sac - attached to their bellies.When they
emerge from the gravel they are called fry.Where they go next
depends on the kind of salmon they are. Coho fry stay in our streams
for a year beforemigrating out to saltwater. Sockeye usually stay in a
lake for at least a year.When salmon are ready to begin their journey
to the sea they are called smolts. Puget Sound chinook and coho
are typically 3-4 years oldbefore they return to lay eggs, or spawn,
in the same streamwhere theywere born. Most salmon species die
after spawning.
Howdoes stormwater affect salmon?
The time salmon spend in the rivers, streams, and lakes of the
Puget Sound region is crucial to their survival. Human impacts to
salmon habitat andwater quality through development of towns
and cities have had a devastating effect on salmon. In urban areas,
polluted runoff from streets is causing salmon, especially coho, to
die before they spawn. Are thereways to filter polluted runoff? How
canwe prevent pollution before it happens? Scientists, engineers,
andplanners areworking onways to getmore of that water to flow
through soil and compost to filter pollutants before it reaches our
streams and rivers.Whilewe do not understand exactly how salmon
are able to navigate back to their birth streams to spawn, scientists
believe a salmon’s sense of smell, combinedwith other cues in their
environment, help them find their way home. Since their sense of
smell helps salmon navigate, pollutants that contaminate thewater
can be particularly harmful. For example, tiny bits of copper from
brakes can accumulate on roads andbewashed into streams, rivers
andPuget Soundwith the next rainstorm.Washington state passed
a law to phase out the use of copper brakes to address this issue.
That’s just a start –we have a longway to go to improvewater
quality for salmon.
Crosswordpuzzle answers:
Across:
2.
Watershed; 3. Storm; 6.
Mulch; 7. Tags; 9.
Compost; 10.
Cascade
Down:
1.
Garbage; 2.
Washington; 4. Pollution; 5.
Chinook; 8.
Kokanee
RIVER
ESTUARY
OCEAN
EGGS
incubate
in streambed
gravel.
ALEVINS
hatch from
eggs, staying
in the gravel.
Once they emerge
from the gravel they
are called
FRY
.
Once frybegin the transition from
freshwater to saltwater theybecome
SMOLTS
. Smoltsmay live in the
estuary until they adapt to saltwater.
From the estuary,
SMOLTS
spend
additional time getting
bigger in Puget Sound
beforemoving
into the ocean.
PACIFICSALMON
live in the ocean.
RETURNINGSALMON
enter the
estuary. They are no longer able to
eat, butmove steadily upstream
using their stored fat reserves.
SPAWNING
SALMON
return to
the streamof
their birth to lay
their eggs. After
spawning, most
salmon species die.
6
SUNDAY, OCTOBER30, 2016 |
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