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.