TOPIC:

Good question, and there'll be a lot of good information coming out over the next few months and following several years. All stocked steelhead are tagged now, although unfortunately there was a gap yearclass in there because the USFWS didn't tag during the initial covid pandemic lockdowns, and no collections of adult tagged fish happened in 2020 either. Poor timing but out of our control. 

We're awaiting the big lakewide dataset to be checked for accuracy and quality before any in-depth analyses are collected for the 2021 collection year. Things that will be of interest are size-related returns, stage (fall fingerling vs yearling), and regional or even stocking site level return rates. With aanother year or two of lakewide collections (and stream collections, please turn in any tagged heads!) we will have a wealth of information to better refine stocking decisions.

Very preliminary results, however, as Ed mentioned, are that Indiana returns to the open lake fishery are the best among any Lake Michigan state. This might change as more data is collected or might not. Michigan was pretty close to Indiana in terms of return rates to open lake fishery. Illinois and Wisconsin were really far behind  - Indiana was more than 3x the return rate of Wisconsin steelhead and more than 12x the return rate of Illinois steelhead. Interesting preliminary results given that Wisconsin has the best chinook survival in the entire lake, but I think that is likely size related - Wisconsin stocks steelhead at a considerably smaller size than Michigan or Indiana. Survival of steelhead smolts increases exponentially as length at stocking increases. Illinois and Wisconsin both raise skamania from eggs that Indiana provides them. Illinois stocks them small as fall fingerlings, and Wisconsin stocks spring yearlings but they are also on the small side.

In terms of movement, again, preliminary results but they are what managers expected - similar to chinooks, the steelhead in the big lake are well mixed, with everybody's fish turning up all over the place. This corroborates some work with steelhead otolith microchemistry that took place a couple years ago. Pretty fascinating stuff, they can use a laser to vaporize the middle of otoliths and read the chemical signatures there ,  which incorporate trace elements from the water in which they were raised, either in a hatchery or in the case of wild fish, the stream they are born in. Then that's matched up against water samples from all the locations. 

There's some information starting to come out on wild steelhead but not enough data to make concrete conclusions beyond things we knew/suspected - otolith microchemistry suggests almost all the wild reproduction is coming from high quality Michigan river systems such as the Manistee/Little Manistee, Pere Marquette, etc. And that the proportion of wild fish is somewhere between 15 and 40%, which hopefully once more lakewide data from collections are analyzed can be narrowed down.

 

Thanks for the update Ben!

So what is the correct answer?  Great info for sure.

Baron2150 wrote:

So what is the correct answer?  Great info for sure.

C Indiana
D Michigan