The autumn winds are blowing through,
the rains are flooding the rivers,
and there's something fishy going on in our own backyard...
Salmon are an important part of the Pacific Northwest. They are vital to our ecosystems and the food chain. They've had a significant role in our economy and cultures for generations and if we want that to continue, we need to understand their life cycle and how the things we do affect them.
In the Pacific NW there are seven types of salmonid that are born in streams and rivers before making their way to the Pacific Ocean and the Salish Sea; Chinook (king), Coho (silver), Chum (dog), Pink (humpy), and Sockeye (red) salmon, and Steelhead and Sea-run Cutthroat trout. Now, as the autumn rains move in and swell the streams and rivers in our backyard, salmon leave the ocean to make their way back to the same lakes and streams where they were born.
The migration is a difficult journey. A salmon's world can cover thousands of miles. An individual salmon can migrate from inland mountain streams to the Pacific Ocean and back, occupying many different habitats along the way. Not only can it be a long trip, through challenging waters, but salmon stop feeding once they reach freshwater; their bodies preparing for spawning and reproduction.
Once they reach the right spot, female salmon use their tail to move stones and pebbles to make little nests in the gravel, while the male salmon fight each other for the right to reproduce with the females. When the time is right, the female will release eggs into her nest and male will spray milt (salmon semen) over the eggs to hopefully fertilize them.
When the eggs settle into the nest of gravel, the female covers them with loose gravel before moving upstream to do this process all over again. These nests are referred to as redds. A single female salmon will often lay thousands of eggs in several redds during her spawning. The eggs that don't get buried in the gravel become immediately available as food for other fish, birds and insects. The adult salmon that eventually die, also provide the rivers and lakes with needed nutrients.
While thousands of eggs may have been laid by a single salmon, up to 80% of the eggs never hatch and very few of the young that hatch actually survive to become adult salmon. Their life would naturally be difficult enough with predators and the damage from being bounced against gravel, but urbanization has added warmer water temperatures, chemicals, and reduced habitat to the equation.
As I said in, 'The watershed in your backyard', urbanization has increased the variety and amount of pollutants carried into our waters. Surface runoff is the primary mechanism for transporting nonpoint source pollutants from land to our waters.
"In our rush to modernize and grow, we have overlooked all of the things that salmon need to be healthy. Because of the wide-ranging and complex life histories of salmon, they are vulnerable to impacts from headwater streams to the open ocean. As a result, salmon stocks are dying the “death of a thousand cuts” from steady incursions into their habitat – a road here, a wetland filled there – that cumulatively have pushed many populations to the brink." (Wild salmon center)
At one time, overharvesting was the biggest threat to salmon, now the loss of habitat is the problem. In Washington, 50-90 percent of land along waterways (riparian areas) has been lost or extensively modified by humans. (https://stateofsalmon.wa.gov/statewide-data/habitat/)
"All land on earth is a watershed. All our activities play an important role in (them)..." (Where does your water shed) Consequently, all our activities play an important role in the health of everything. No exceptions. As we shape our world to our needs and desires, we need to consider how the results will affect everything else.
With a bit of forethought and planning we can do great things without harmful effects to everything else in our environment.
Salmon Need Healthy Places to Live. This means rivers with cool, clean water and a variety of habitats that allow fish to rest, hide from predators, and spawn. It means intact estuaries where salmon can grow and transition to and from saltwater. And it means rivers and shorelines with ample food.
Forested riparian areas:
Have trees and plants that provide shade which keeps the water cool
Have trees and plants with roots at the waters edge to prevent soil from entering the water and burying spawning gravel.
Have trees and plants that filter polluted runoff before it enters rivers, lakes, streams, and oceans
Have trees and plants that reduce the growth of algae into harmful algal blooms which consume oxygen and create toxins.
Have trees and plants that drop branches, leaves, and insects into the water, increasing the amount and quality of habitat in streams
Floodplains:
Slow and store water during all times of the year
Provide shelter and food for young fish
Buffer local communities against floods
Side channels (little, calm pools that jut out to the side of rivers and streams).
Slow safe areas for eggs and young fish
Our human habitat (urban and suburban areas) has covered much of these previously forested riparian areas with impenetrable surfaces, such as buildings, pavement and compacted landscapes. These surfaces do not allow for infiltration, so more water runs over the surface of the land transporting warmed, polluted water to streams and other watersheds already suffering from lack of shade. But that doesn't need to be the case.
There are plenty of ways to help salmon.
Use natural yard resources and wash your car in an environmentally friendly way. Pesticide, fertilizer, and other chemical runoff can pollute rivers, streams, and other bodies of water.
Planting trees and shrubs near rivers can also help prevent erosion into rivers and provide a variety of resources for fish and wildlife including birds, bees and other pollinators.
There are many ways we can help as individuals or as groups the salmon and, consequently, many others including ourselves and our ecosystem. (How You Can Help Protect and Recover Salmon )
We need to take action for their wellbeing and our own.