Category Archive: Science Friday

Science Friday: Who’s who in the Elwha after dam removal

By John McMillan   We should not be surprised by steelhead and salmon rushing upstream to pass former dams. That is their nature — to push boundaries, access new habitat. Unbuild it, and they will come.   And come they have in Washington’s Elwha River, where in 2014 two old dams were taken down. Not … Continued

Science Friday: Why are half pounders declining in the Trinity River?

When anglers dream of steelhead, they mostly fantasize about fish that have spent 2-4 years in the ocean and return to freshwater to spawn as full adults, packing four or more pounds and brutish power into their physique. However, one of the most common forms of returning steelhead in some rivers is not the adult, … Continued

Science Friday: Behavioral Thermoregulation

Most steelhead anglers know that the family of fishes called salmonidae (trout, char, salmon and whitefish) are highly sensitive to water temperature and quality. These fishes require cold, clean water to thrive. But what happens to them when water temps become unfavorable? As you might expect, they seek out places in the river that regain … Continued

2017 – a Bad Year or Part of a Trend?

Ocean conditions are vitally important for wild steelhead runs — probably every steelhead angler knows this. But what does that phrase really mean? The ocean is a massive and incredibly complex system, and there are many factors out in the big blue that can influence steelhead in any given year. That is why it is … Continued

Science Friday: More on summer and winter steelhead genetics

By John McMillan Two weeks ago we reviewed a study by Prince et al. that discovered a single gene differentiated steelhead which return immature (referred to as pre-mature in the study) to freshwater (i.e., summer steelhead) and those that return in a mature or relatively mature state (i.e., winter steelhead). Anglers have long known there … Continued

Rise of the Phoenix: wild summer steelhead in the Elwha River

By John McMillan, science director, Trout Unlimited Wild Steelhead Initiative   A few years back, while working on the Elwha dam removal project, I donned a wetsuit for one of many snorkel surveys I conducted that summer. I had been snorkeling the main-stem Elwha, but that day – a crisp cool day in mid-October – … Continued

Science Friday: How summer steelhead are genetically different than winters

Many anglers over the years have no doubt wondered why some steelhead return to freshwater during the hottest and driest part of the year. The reasons why are both simple and complex.   The most obvious difference between summer steelhead and their winter run brethren is that they enter freshwater streams in summer and fall, … Continued

Science Friday: Warm water’s influence on the speed of upstream migrating steelhead

The dog days of summer are fully upon us. The predicted forecast for adult summer steelhead returning to the Columbia and Snake River basins is now, unfortunately, shaping up to be worse than expected (and it was already very low). However, it can be difficult to determine how accurate this forecast actually is because at … Continued

Science Friday: Steelhead in hot water, and what it means for catch-and-release

As predicted for summer steelhead in the Columbia River and many other watersheds in Washington and Oregon, something has happened to the fish. There are precious few of them this season. But it’s important to remember that ebb and flow in population size is part-and-parcel with these fish — and for all salmon in general. … Continued

Science Friday: Turn up the A/C

Summer-time is here. That means hot weather and hot water, two things that don’t mix well with a cold-water fish like steelhead.   As we suffer through the largest heat wave of the summer, we wanted to review a piece of research that looked at how adult steelhead alter their behavior and use micro-habitats to … Continued