In recent posts we covered the basics of defining escapement and run size, and the ways these are measured by resource managers. Today, we turn our focus to the complex terminology used for describing and comparing hatchery and wild steelhead. Steelhead are typically referred to as either being “wild” or “hatchery,” but they may also be defined as being “native” …
Steelhead 101: Estimating steelhead run size
Recently we have described the various methods used by biologists and resource managers to estimate steelhead escapement, which is the number of fish that escape and survive fisheries (all forms of angling) to actually spawn in a watershed. Run size is the total number of steelhead that return to a watershed each year. In order to estimate run size …
Steelhead 101: Using weirs to estimate adult steelhead escapement
Recently we have described how scientists use redd counts and snorkel surveys to estimate steelhead escapement. This week we focus on weirs, a totally different way of counting steelhead. Rather than sending out surveyors to sample stretches of stream where they count redds or fish, the operation of a weir is much simpler. A weir basically blocks the river and …
Steelhead 101: Using snorkel surveys to estimate adult steelhead escapement
Another week, another post on how scientists and fisheries managers measure steelhead escapement. Last week, we described redd counts and why they are an important tool. This week, we review snorkel surveys. Snorkel surveys entail divers swimming in the river and visually counting adult steelhead. Like redd counts, snorkel surveys do not cover an entire river, but rather break …
How many steelhead can you fit into a school?
It depends on how old and big they are. Over the past year we have talked extensively about the value of life history diversity in steelhead, and in particular, that a broader range in spawn timing – which results in a broader range of emergence for juveniles – can help ameliorate density-related impacts by spreading steelhead of various ages …
Science Friday: Tillamook Bay Steelhead
Do you ever wonder what we might be missing nowadays in terms of steelhead life histories? Although we can’t go back in time to answer this question, we can look at historic data — in this case from Oregon’s Tillamook Bay. By the 1940’s Oregon’s Tillamook Bay was a patchwork of homesteads and farms, appearing more like the present day …
What happened to our Columbia River steelhead?
By now, you have probably heard steelhead returns to the Columbia are well below the most recent ten-year average. As a result, places like the Methow River will not be open to steelhead angling this fall. In short, that is a bummer. There has been much speculation about the causes for the decline and potential fear that changes …
Juvenile steelhead doing what it takes to become a smolt: You grow in summer, I’ll grow in winter
Another Friday, another blog post on the science of steelhead. We love this day of the week! Our topic this week is the growth of juvenile steelhead. Did you know that the growth rate of steelhead can vary depending on the season of the year? This variation in growth rate can be considerable. There are a number of reasons that …
Steelhead biology for anglers
One thing you will notice about anglers who have spent a lot of time on the water, and I mean a potentially unhealthy amount of time on the water, is they catch fish. This can be frustrating to new anglers who are just learning to steelhead fish and spend many fishless days casting. There is no substitute for time …
Time to rethink what you thought you knew about steelhead
John McMillan I bet we all think we know what a steelhead is: a rainbow trout that goes to the ocean and returns to spawn in freshwater. I agree. But, new research indicates that the definition may not be so simple. Jason Hall, a researcher with NOAA in Seattle at the Montlake Lab (Northwest Fisheries Science …