At the beginning of the month, we launched the first of a series of posts we’ve dubbed ‘fish facts,’ where we share weird, quirky, or just plain interesting nuggets of truth about the species we pursue at our lodges.
Today’s fish fact sheds light on the ever-confusing topic of winter versus summer steelhead.. What exactly is the difference?
Winter vs. Summer Steelhead – What’s the Difference?
Conventional wisdom would suggest the difference between the two lies in run timing. Winter steelhead enter fresh water in the winter and summer steelhead enter freshwater in the summer, right? Not necessarily.. Run timing is surely where both races of steelhead get their name, but any hardcore steelheader will tell you there is always the potential for a fair amount of variance in run timing. Particularly those systems which experience runs of both winter AND summer steelhead.
So what distinguishes the two? Winter steelhead enter freshwater sexually mature, while summer steelhead enter freshwater sexually immature. In other words, winter steelhead are potentially ready to spawn immediately after entering fresh water, while summer steelhead require several months in freshwater to mature before spawning.
Sexual maturity is the distinguishing factor between winter and summer steelhead, not necessarily run timing. However, Ocean-Maturing and Stream-Maturing Steelhead just doesn’t have the same ring to it, so we’ll continue to call them winters and summers.
Hi……….read your winter/summer chromer article and tied some ‘B.Bees’. Would add only that the distinction bet. the summer/winter fish also depends on a river’s ‘summmer flow’. If it is essentially non-existent as with too many rivers these days the genetic pool of ‘summer fish’ is usually lost. Exception may be hatchery brats which brave anything. Best example is Dean where summer flows usually stay excellent and in winter there isn’t enough water to let fish migrate. (this summer exception where low July water meant running fish and not holding/taking fish) I would hope and assume that if we get summer flows up in some rivers (dam removal, water release) we will see returns of that gene pool. thanks for a fun blog Grampus
In my experience it seems that along with sexual maturity, Winter Steelhead also tend to be larger.
But, what about Fall Run Steelhead? Would they be more akin to Summer Run, in that they reenter fresh water sexually immature, and must spend several months growing/eating in order to obtain sexual maturity?
Fall run fish, such as they have on the Klamath and the Rogue for instance, seem to coincide with the return of the Chinnook Salmon (mid October – flow dependent) and the spawn which follows. This salmon spawn results in a large amount of food for the fall fish, which would seem to support the notion that they have not yet reached sexual maturity, as they are incredibly food motivated.
Here is the latest genetic studies explains why the difference :
http://www.wildsteelheaders.org/science-friday-how-summer-steelhead-are-genetically-different-than-winters/
I caught a summer (June 23rd) several years ago. He was 39 inches long steelhead. Have you any idea if this is close to a record. Clackamas river or. Thanks !