Category Archive: Science Friday

Science Friday: Do it once, do it twice. The tradeoffs of repeat spawning in steelhead

We are back after a short break, after coming through a heavy dose of conservation work. That work, in part, helped convince the Washington Department of Fish and Wildlife and the National Marine Fisheries Service to re-open the iconic Skagit River for a catch-and-release season for wild steelhead. It feels like a new day has … Continued

Stock Recruit Curves And Wild Steelhead, A Good Match?

In several recent posts we have discussed the concept of density dependence and how it is used in fisheries management. Today we dive in deeper and talk about the stock-recruitment relationship, density dependence, and how the results of such models are applied to managing steelhead.   First, let’s define some terms. Stock refers to, in … Continued

Science Friday: Why do juvenile steelhead move at the onset of winter?

By John McMillan We are going old school today, Science Friday style. No, we’re not talking about shooting ourselves with a tranquilizer gun, going streaking, or starting a fraternity to compensate for a mid-life crisis. We’ll leave that to Will Ferrell.   But we are going back in time, to 1971. Today we revisit one … Continued

Science Friday: Steelhead fry party when the lights go off — but will they wake up high and dry?

In our last Science Friday post we took a look, in part, at the feeding behavior of bass. This week we are moving down in the feeding column to focus on catfish.   Just kidding. It’s all steelhead all the time here.   Today we review a paper by David Hines and several colleagues. The … Continued

Science Friday: Are some fish caught more than others, and if so, why?

We’re deep in the heart of winter steelhead season now. But if you’re like us, you are probably suffering from high-wateritis right about now — a common affliction for winter steelheaders.   Living on the Olympic Peninsula, I have it bad. Non-stop rain for days. Rivers punched. Headaches due to lack of chrome-ium. Conditions better … Continued

Science Friday: Space, time, and maximizing habitat capacity

All steelhead, all the time, here at Wild Steelheaders United. Over the past few weeks we have examined the scientific concepts and tools used to evaluate how productive a given stream can be for wild steelhead. Such assessments are an important component of managing a steelhead fishery — especially if the run in that watershed … Continued

Science Friday: The importance of both space and time in managing wild steelhead

  This is the third of four posts on the nuts and bolts of estimating wild steelhead populations, spawning success, and other key management variables.   First, we covered the concepts of carrying capacity and density dependence and how habitat can be used to estimate carrying capacity. Last week’s post shifted gears to review studies … Continued

Science Friday: Juvenile Density, Distribution and Habitat Capacity

By John McMillan New Year, new Science Friday! Last week we looked at the concept of carrying capacity, how it is estimated, and the most important habitat factors used to come up with those estimations. This week we shift gears a bit and review studies that illuminate how patterns in fish distribution can affect assumptions … Continued

Science Friday: The habitat that steelhead prefer, and how we use it to estimate capacity of rivers

By John McMillan How many steelhead can you fit into a given watershed? Put another way, what is the carrying capacity of a given watershed for steelhead? This question, and its answer, are important for steelhead fishery managers, and anglers, as we collectively try to rebuild wild fish runs up and down the West Coast. … Continued

Science Friday: The fate of stranded post-spawn adult steelhead

By John McMillan   One significant way in which steelhead differ from salmon is that O. mykiss have the ability to survive spawning and try to make the journey again. This behavior is referred to as repeat spawning.   Repeat spawner rates are highly variable among populations of steelhead, with rates being higher in coastal … Continued