Three of us fished a Great Lakes tributary for steelhead prompted by a call from Kevin to tell me he was seeing near-constant "flashing" males (males flipped on the sides fanning the gravel to make a redd). We actually caught more fish, but two of us sorted fish to only keep hatchery origin fish. This river has some really beautiful scenery as well, courtesy of two waterfalls, one of which serves as the upstream limit. Today's rain will really start pulling fish in. Time to get the boat uncovered and start trolling for spring salmon as the diatom hatch peaks. Smelt numbers are rumored to be up on Superior. T,he "stubby" male posed at a right-angle to the other fish has a broken spine at the caudal peduncle. Kevin supplied the ties to just drop fish along the bank. He said he has never had a fish stolen...
Rods were 9' 8WTs. with a sink tip. Scented beads, egg flies, and #10 black or brown stones and peacock buggers took all the fish.

Looks like a lot of fun fishing. The "stubby" one with a broken spine. Is he a wild fish that you kept because he has a broken spine or was he also a hatchery fish? I am just curious because he is so much prettier than the others. Or is he just "fresher" than the others?

Dani, in salmonines (salmon and trout), males arrive prior the females to stake-out their spawning redds and defend them, basically apportioning the existing substrate. Steelhead tend to darken once they enter rivers from the Great Lakes, a physiologic response that minimizes their contrast against the background; converse when they are back out in open water. The brighter lateral red/pink is a secondary sexual characteristic influenced by hormone levels. Look closely at the heads of these fish; they ones with the rounded snouts are hens and the fish with the more pointed snouts are males. Some of the males are developing kypes as well, indicating how close they are to spawning. I kept the broken back male because he was a hatchery fish with an AD clip. The USFWS has been running a Coded Wire Tag program for nearly a decade now assessing movement and seasonal distribution patterns of Great Lakes salmonines, with all AD clipped fish containing a micro tag inserted in their snouts prior release. Each CWT array is recorded by plant site, with USFWS techs. gathering heads and removing the CWTs to record their origin site.. This initially was targeted at chinook and coho for nearly a decade to determine movement, resulting in the documentation of seasonal and annual movement of these species, wild origin and hatchery derived stocks, freely between Lakes Michigan and Huron, something I and several others have been trying to convince the State fishery managers was occurring since 2007. Lake trout, and now steelhead are receiving CWT via a trip through the mass-marking trailer where fish are fed into a hopper, sucked into a tagging chamber that scans the fish several times prior simultaneously inserting the CWT and swinging a razor blade across the base of the adipose fin. Tagged fish are released into another holding hopper where they are visibly inspected to make sure they were marked as well as to verify that they did not invert in the marking chamber (this was designed for Pacific salmon but has been modified to used for other salmonines that are not as deep dorsal-ventrally. Lake trout were the big variant.)

Fish often are swept up from their raceway and dumped out on a barred grid to size sort them, with some fish injured in the process. Often in a three pass raceway system the fish in the third raceway exhibit slower growth due to increases in nitrogenous waste products from fish excretions across their gill membranes, as well as in the excrement. When I took fish culture Harry Westers rotated fish from last to first based on his growth criteria for Michigan's hatchery system.

Well, there's my science fix for the day!

Cool info. Do the steelhead compete with the native coaster brookies? Or do they spawn at different times?
Any numbers on how successful their spawning efforts are in recruiting juveniles back into the population?

---

Carl
Mobile, AL
DHBP Member since 1998

"Life is too short to drink bad beer."
Disclaimer: This post and/or report is not a substantiation of or reflection on the true accuracy of the present surveying methods. It is only a report on or comment concerning local observation and/or results. Your results and observation may vary based on your location, local water conditions, food supply, weather conditions and migratory patterns "

Other than the folks working on the Nipigon River population the general data indicates that coaster brook trout are largely excess production the emigrates from flash basin streams in good production years where YOY fish exceed carrying capacity and end-up in open lake waters. USGS, and MiDNR researchers tagged native brook trout and planted coaster strain fish with small electromagnetic insert transmitters that generated two distinct signals in three streams that discharge into Lake Superior. They laid electromagnetic generating cables in the substrate at the mouths of these streams and recorded annual emigration rates of each brook trout stock. Over the duration of the study native brook trout emigrated to open lake waters at a higher rate seasonally and annually that the coaster strain plant fish, largely negating the genetics driven hypothesis with regard to what makes a brook trout a coaster brook trout. The more abundant food resources (many of the Lake Superior tributaries that contain basins consisting largely of Canadian Shield igneous rock formations also form anchor ice deposits in severe winter weather intervals, diminishing primary and secondary production and productivity.

Niche overlap and degree of annual resource competition among Great Lakes salmonines, stratified by open lake quadrant in Lake Michigan was quite convincingly addressed by Matt Kornis, USFWS researcher at their Green Bay Facility:

(PDF) Spatiotemporal patterns in trophic niche overlap among five salmonines in Lake Michigan, USA (researchgate.net)

Those of us who argued that the MDNR, WDNR, IDNR, and Illinois.DNR managers made a massive mistake when they collectively opted to choose a fifty percent reduction in chinook plants (Option 2) over the option of applying a multispecies plant reduction approach based on bioconversion and consumption efficiency data (Option 4) in spite of each Decision Analysis Model scenario "run" one hundred, one year iterations, yielding a significantly higher probability of generating a great alewife population stock via the muli-species reductions when compared to the single species reduction option. What drove their decision? They would not have to toss fish in the hatchery rearing systems that were species dependent on multi-year rearing cycles.

They saved some hatchery fish.. avoiding having to explai to the politicians why they threw the in a landfill.and nearly crashed the entire open lake population, very nearly destroying a multi-billion dollar fishery!

Pre-dreissenid mussel invasion, spring diatom blooms largely drove the productivity of inshore Great Lakes waters providing high free fatty acid content forage for cladoceran zooplankton as well as the inshore native Gammarid amphipods and their deepwater cousin, Diporeia sp., as well as Mysis diluviana stocks. Post-spawn alewife would move offshore into waters > 150 FOW to feed on Diporeia sp. and Mysis sp. to regain somatic energy stores that they had "tapped" to make gametes Coincidentally, Diporeia sp. and Mysis sp., as well as cladoceran zooplanktors are at their annual peak in proportional free fatty acid concentrations in body tissues in mid-Ju;y. Dreissenid mussel colony filter feeding has markedly impacted bothe the scope and duration of the inshore diatom blooms in the lower Great Lakes that they infest now. In 2007 there were roughly 9 age-classes of alewife within the Lake Michigan stock. Doctor Kornis was able to document, via stable isotope food habit assessment analysis techniques that lake trout stocks that surpassed Pacific salmon stock numbers over the 2007-2009 interval feed preferentially on these adult (3YO and older fish) alewife, while most of the remaining salmonines have converted to feeding on the more numerous juveniles stock component, including chinook, the largest annual alewife consumer population in open lake waters. Consequently, driving the shift in the age structure of the alewife stock to one consisting of age-! and Age-!! fish and a smattering of adults carrying the open lake population in Lake Michigan. MSU's Quantitative Fisheries Center has now developed a multi-species predator-prey model based on species specific salmonine predator stock and prey forage stock biomass that is replacing the old single species Chinook predaotor-alewife prey model used since 2013 to inform species specific annual plant rates, as well as co-factoring in wild origin production of chinook, coho, lake trout, and steelhead.