Salmon runs, where adult salmon return from the ocean to their freshwater birthplaces to spawn, are a remarkable spectacle. Washington State provides a significant stage for this annual migration due to its abundant rivers and diverse salmon populations. These runs are a cornerstone of the region’s ecological balance, providing food for wildlife and enriching river ecosystems. The timing of these events varies, making it essential to understand the different species and locations involved.
Salmon Species and Their Seasonal Returns
Washington State hosts five primary species of Pacific salmon, each with distinct seasonal return patterns. Chinook salmon, often called King salmon, are the largest and typically have runs from late spring through summer, with some rivers seeing them as early as March or April and peaking in August. Coho salmon, also known as Silver salmon, generally run in the summer and fall, with peak months occurring from July through September, though activity can extend just before and after this period.
Pink salmon, or Humpies, are unique as their significant runs primarily occur in odd-numbered years. These fish flood the waters during late summer, peaking in July and August, with some presence extending into September. Chum salmon, also referred to as Dog salmon, tend to run later in the year, with some appearing in late summer (July and August), but their largest numbers arrive in October, November, and December.
Key Washington Rivers and Their Run Schedules
The Columbia River, the state’s largest, sees significant runs of Chinook and Coho salmon, with Sockeye runs also present in some years. Sockeye salmon typically enter the Columbia River in June, with upper Columbia arrivals peaking in early July. Puget Sound and its associated river systems are active throughout the summer and fall, with Chinook runs peaking in August and Coho present through the summer. Pink salmon can also congregate in strong numbers within Puget Sound, especially in areas like Marine Area 10 (around Seattle), peaking in mid-August and continuing into September as they move into rivers like the Nisqually and Green.
Rivers on the Olympic Peninsula, such as the Sol Duc, Bogachiel, Calawah, and Hoh, offer robust fall runs of Chinook and Coho salmon, typically from early September through November. The Sol Duc River is known for strong Coho runs in late September and early October. Kennedy Creek, located near Olympia, is particularly known for its productive Chum salmon runs, with thousands returning every November.
Factors Affecting Run Timing and Success
While general timelines exist, the precise timing and strength of salmon runs can fluctuate due to various environmental factors. Water temperature is a primary influence, as salmon prefer cooler waters for migration and spawning. If water temperatures become too warm, typically above 68 degrees Fahrenheit (20 degrees Celsius), salmon may delay their migration or seek deeper, cooler areas, which can lead to stress and reduced survival. For instance, sockeye salmon do best when water temperatures are 60 degrees Fahrenheit (15.5 degrees Celsius) or below, and temperatures exceeding 72 degrees Fahrenheit (22.2 degrees Celsius) in the Columbia River have been linked to significant sockeye losses.
River flow levels also play a significant role; adequate flow helps salmon navigate upstream, while low flows can impede migration or strand fish. Ocean conditions, influenced by cycles like El Niño and La Niña, affect salmon survival and, consequently, the number of fish returning to rivers. El Niño events often bring warmer ocean temperatures and less productive food webs, which can negatively impact juvenile salmon growth and survival, while La Niña typically brings cooler, more favorable conditions.
Observing Salmon Runs Responsibly
Observing salmon runs is a privilege that comes with the responsibility of minimizing human impact on these sensitive ecosystems. When viewing salmon, it is important to remain on designated paths and viewing areas to avoid disturbing the fish or their spawning beds. Approaching fish too closely can stress them, potentially disrupting their crucial spawning activities. Viewers should avoid walking in streams where salmon are present, as eggs laid in the gravel are easily damaged.
Resources from local fisheries departments or conservation groups often provide information on specific viewing locations and guidelines for ethical wildlife viewing. Checking these sources can enhance the experience while ensuring the well-being of the salmon.