Lakeside Living
Learning to live with the lake, not just on it
Do you know there are "kids" hiding off your shore?
Photo: Shapiro & Associates
Your shoreline is a nursery for young salmon.
Each winter thousands of young chinook emerge from our creeks and streams to begin their journey out to sea. Most are gobbled up by predators before they ever make it to salt water. Lakeshore property owners play a vital role in salmon survival. You can improve their childhood home as you protect and care for your own home.
Who’s hiding off your shore?
Once WRIA 8 chinook leave their natal creeks and streams they enter either Lake Washington or Lake Sammamish to begin their fresh water existence. At this stage they are known as fry or parr, as noted by the parr marks on their sides. Fry spend their time in the lakes between February and June.
Just as there are some human kids who want to run away from home at an early age while others seemingly never want to leave the nest, juvenile chinook have two different rearing patterns. Most fry from the Cedar River migrate into Lake Washington at a younger age and spend more time rearing in the lake than fish from the north Lake Washington tributaries (Kelsey, Bear, Little Bear, Swamp, and North Creeks). Fish from the Issaquah hatchery are released later as pre-smolts or smolts, the stage where they begin their transition to saltwater. Though the fish are bigger and spend less time in Lake Sammamish and north Lake Washington than their counterparts in south Lake Washington, juvenile fish still need good habitat to survive.
So what do young salmon need?
Like humans, juvenile salmon need food and shelter.
Food
In the wild, salmon eat insects (think fly-fishing). But the types of bugs they eat are ones specifically associated with native lakeshore vegetation, such as rushes, willows, dogwoods and maples – plants that have mostly been replaced with lawn where residential development has occurred. Without the host plants, the bugs that salmon like to eat don't exist. Lacking this food source, young salmon have adapted their diet to exist primarily on microscopic invertebrates found in the water – critters such as zooplanton, aquatic insect larvae, daphnea (water fleas), mayflies and caddisflies. While young salmon don't appear to be starving, a diet devoid of terrestrial sources is not their traditional fare.
Shelter
Photo: Roger Tabor, US Fish & Wildlife
Photo: Roger Tabor, US Fish & Wildlife
While juvenile salmon must compete for food to survive, predation is the leading cause of mortality. Only one percent of chinook fry ever make it to the ocean. They need protection from predators that like to eat them before they get out to sea.
Who are the neighborhood bullies?
- Cutthroat and searun cutthroat trout – the most adaptable salmonid to the urban environment; prolific feeders on chinook, prefer deeper water.
- Large and small mouth bass – voracious predators of chinook. Begin feeding frenzy when water has warmed up, lurk under docks, at bases of pilings, hide in rocks of rip-rap bulkheads.
- Sculpin – aggressive predator, hides in rocks and under docks.
- Northern pikeminnow – voracious predator on salmon smolts.
- Yellow perch – have a big impact on smolt survival in Lake Sammamish.
- Shorebirds, such as heron, seagull, eagles, and cormorants – fish are defenseless without cover to hide under.
Camouflage or bullseye?
Note the parr marks on the young salmon? These bars and spots along their sides are designed to camouflage the fish as they hide amidst stumps, root wads, beneath overhanging vegetation, or within branches that have fallen into the water. Without lakeshore vegetation against which these fish can use their camouflage, the parr marks might instead make juvenile salmon more noticeable to predators.
As plants mature, branches will arch out over the water. Some will eventually fall off into the water. We refer to the branches as woody debris. Though the name doesn't sound very complimentary, woody debris provides baby fish with an extremely valuable tool for survival: refuge from pedators, whether swimming in the water or flying up above.
Ironically, in our well-intended efforts to be responsible homeowners, we can unknowingly create conditions that put young salmon at risk. When native vegetation is replaced by lawn and all of the maintenance that goes with it, the survival of young chinook is compromised. When we modify the lakeshore by building docks and bulkheads we can also inadvertantly increase their risk by stacking the odds in favor of predators.
Learn more at Lakeside Landscaping