2017 MS Creel Project Results
Beginning in 2010, Minnesota Steelheader has annually collected and compiled voluntarily submitted creel reports for the following species: steelhead, kamloops and presumed coaster brook trout. While the primary focus has been fish caught in the tributaries during the Spring migration and spawning run, we appreciate and accept creel reports year-round. MS takes those reported catch dates, region caught, the numbers by species, measurements of daily flow, temperature and other open-source data, then analyze them using a variety of different tools. The results are plotted in Daily, Weekly and Historical formats in what we hope are informative and easy to use charts.
This is not a scientific creel by definition, we do however incorporate, use and present as much of the available scientific literature as we can with the goal of making you a more knowledgeable, and most importantly, a more successful North Shore steelheader. The creel data is collected by you, we've re-assembled it along with all other submissions and data from a fishing perspective, we hope you find it useful.
Creel Project Basics and how we prepare the data
Minnesota Steelheader began with the premise of Informing, Educating, Entertaining and Inspiring both new-comers and veterans alike. The Creel Project looks to answer some of the most basic questions we receive year after year from newer anglers:
- When do the fish run?
- How long do runs last?
- When is the "best" time to go?
- How might I plan a trip, particularly if I have to travel long distances or only get one or two opportunities to get out and fish each year?
- Are there distinct differences in run timing and duration between the various regions of the North Shore?
- Is there a typical run timing and what does that look like for each region?
- How do flow and temperature affect steelhead returns, fishing and presentations?
- What other species data can we use to corroborate "run timing"?
- Daily Reporting: Daily reported creel is plotted against both flow and temperatures to help you visualize the more granular interactions between steelhead and the primary environmental factors of flow and temperature
- Weekly Reporting: As the migration or run progresses, these daily creel reports are plotted in a weekly format. This removes a lot of the day-to-day noise, and helps you to visualize the overall progression of the current-year's run
- Historical Reporting: The weekly numbers from each region are nested within all of the previous years of data we have to create a unified historical picture, both at the Regional as well as Shore-Wide level, and these historical charts provide the context for looking ahead. They are not a prediction by any means, but it does provide the framework to understand the basics of any given migration: When do the steelhead and kamloops typically start, when do they typically peak, and when do they typically end? These charts also include the earliest start and end dates reported historically in Regional and overall North Shore formats
2017 Creel Project Results
In 2017 we not only saw very good numbers of fish reported, there were a significant number large fish reported on the Lower Shore and elsewhere. One note of caution about the numbers below. They may seem contradictory to the previous numbers statement, but this was strictly the result of a problem we had with our creel reporting page. The three primary issues encountered were:
- Dates for reported catch were dropping off the submitted form making the data unusable on our end
- Reports submitted by anglers not being forwarded from the server to the creel mailbox and were not recoverable
- Inability of anglers to submit any data to the creel page. Reports were erroring out at the time of submission
That being said, our first Lower Shore stream reports started (reliably) coming in on March 28th with our last submission coming on May 19th for a total of 53 days. This reporting period was roughly 14 days shorter than 2016 but again, we know we lost reports both early as well as during peak returns. Total numbers of fish reported were as follows:
- Steelhead: 195 and 57% of 2016 totals
- Kamloops: 176 and 81% of 2016 totals
- Brook Trout: 31, a 238% increase over the 2016 totals
We'll talk about the brook trout data shortly, but we are seeing some interesting possible correlations between overall brook trout catch, timing and rainbow trout (steelhead+kamloops) returns.
As with virtually all previous creel regions and years, major upstream migrations of steelhead occurred at the point average daily Lower Shore stream temperatures reached what Minnesota Steelheader now calls the "Major Migration Threshold". We previously used the working term "Initiation Threshold", but a number of good discussions with followers on the Facebook page forced us to re-evaluate that language as it just didn't accurately describe what was happening.
DNR fisheries literature for the North Shore discusses this concept although they don't use the term MS has adopted to illustrate the concept. And while there are more parameters involved than what we typically present, the basic threshold for major migration of up-bound adult steelhead occurs when average daily stream temperatures reach and maintain approximately 38°F. The problem with previously using "Initiation Threshold" was that it implied up-bound migrations did not occur until that point was reached, and that is simply not the case. Migration movement does in fact begin prior to the threshold. We know from both the Creel Project as well as DNR Fisheries Trap data that approximately 10% of steelhead and kamloops on the Lower and Mid Shore return to creel and trap prior to the Major Migration Threshold (MMT). Once MMT is attained however, all of our annual data for each region demonstrates that high numbers of adult steelhead, >75%+/-, return to creel over the next 7-14 days.
From a fishing perspective, there is variability in MMT between each stream. Smaller streams reach this threshold as they to warm to MMT daily averages more quickly than larger given similar conditions. Our Lower Shore index streams (streams that have data packages on them) are smaller and tend to hit the threshold several days to up to a week prior to larger streams such as the Knife. This is the primary reason you typically see a delay between posted MMT temps, and strong initial returns reported in the creel trend on any given chart; the index stream is hitting MMT before the larger streams where the majority of steelhead fishing and subsequent creel reports are taking place.
High flows also have an affect on fish movement related to MMT. Streams with flows above known up-bound limiting rates at the time MMT is reached will show delays in up-bound migration. A good example of this is the Knife. The known discharge limiting threshold is right around 500cfs. Above this value, up-bound migrations of steelhead and kamloops effectively ceases. The point being that fish already in the system tend to ride it out by holding tight in areas where they can avoid high current speeds. New fish move into the system in low numbers if at all despite having reached MMT. When flows drop below 500cfs, fish movement resumes. Depending on how long it takes for flows to drop below limiting discharge/flow rates, there may be a fairly significant delay between MMT and up-bound movement. We saw this illustrated very well on Mid and Upper Shore streams in 2016. This is something to keep in mind as you need to adapt and potentially change locations fished within a stream along with changing presentations and tactics. Using much bigger baits/flies and much brighter or very dark colors, potentially using scent, and fishing in out of the way quieter water such as below inside points for example during high flows are a few examples of how to approach raging, chocolate yeti conditions.
One more note about the daily charts: The daily maximum and average stream temperatures are actual with the dotted red line representing MMT. The stream discharge or flow would have to be multiplied by 10 to get the actual number although we don't provide the numbers on the axis for the Daily chart. We do this simply because were we to post the flow number as actual, it would flatten out all of the other temperature and creel trend numbers making it difficult to see the detailed interactions between flow, temps and creel trend . The trend? That is just a trend based on the numbers of fish reported, not the actual numbers themselves.
Lower Shore Daily Data
The Daily chart for Lower Shore below illustrates some of the detailed interactions between flows, temperatures and creel trend. Flows were very high during the early stages of the spring migration, well above 500cfs on the Knife. As they began to drop and temps approached MMT, creel began trending upwards. We hit MMT late on the 6th of April into the morning of the 7th as indicated by the red arrow, and creel immediately increased. Flows dropped significantly along with creel trend, but as we received the next bump in flow from precipitation, creel trend again climbed between the 16th and 17th. Slight decrease on the 20th as flows peaked above up-bound limiting thresholds, but as flows began dropping, the trend picked up again.
April 24th through the 26th is when we received a cold shot of weather, and average daily temps on the streams tanked along with creel. This is a great illustration of why a thermometer is a must-carry for every steelheader. When temps tank like this, sometimes moving to find a degree or two warmer water makes all the difference between hooking fish, and a day spent flogging water.
Average daily stream temps rebounded between April 28th and May 10th with a corresponding increase in trend despite low flows. From then on we were into the tail-end of the Lower Shore run.
Final thoughts on the 2017 daily trend charts: We are beginning to pay close attention to daily average and maximum stream temperatures during tail end of the run. We began this in 2016 as part of the goal to answer questions regarding how long a typical run lasts from a regional perspective, as well as at what point do the adult fish leave the streams. We can't say anything yet for sure; the developing picture seems to be that once average stream temps reach somewhere in the 53-56° F range, the fish seem to raise the white flag and call it quits for the year. The Knife trap data has shown adults staying in the stream for up to 60 days, but that system is far different from most other North Shore streams. We are interested in figuring it out for all those other smaller streams to see if there is a temperature correlation involved, or if we are perhaps barking up the wrong tree.
Lower Shore Weekly Data
The weekly creel project charts better illustrate how the 2017 run progressed over time. We present this chart because as explained above, it removes much of the noise in the daily charts. It also helps illustrate similarity or differences in the annual runs from a regional perspective. This is probably the best chart to use for comparisons between one regional year's run and the next, along with comparing similarities or differences between Lower, Mid and Upper Shore run progressions in a given year. What we think we have learned from this particular chart is that the orderliness of the chart supports the hypothesis that there is in fact a very typical run progression once we have reached MMT, and that they look very similar year after year for each respective region. Once you know where you are at in any given run using the week of MMT as a marker, you can use the normalized regional returns by temperature illustrated a little later in this report to understand what is likely to happen over the next couple of weeks. You can plan where you are going to fish and how you are going to do it. This is all predicated on using the MMT as your starting point. We'll get into that more below.
For now, the 2017 Lower Shore Weekly is a very typical picture we see year after year: Peak up-bound migration and subsequent creel as MMT is attained lasting for roughly 10-14 days, followed by decreasing catch over a several week period. While the daily charts only illustrate overall catch trends and not actual numbers, the weekly chart shows the actual creel numbers reported for both species by week along with average weekly stream temperatures and flow. Posted flow does have to be multiplied by 10 to get the actual figure; it has been divided by 10 and plotted to reduce flattening of the other data-points.
The granular interactions aren't as readily apparent here simply due to the weekly format, but there are a couple items of note:
- DNR Technical literature notes a slightly lower run and spawning temperature in kamloops when compared to steelhead. Lower Shore has the greatest number of kamloops due to efforts to limit genetic introgression of kamloops genes in steelhead through the stocking plan. And although straying of kamloops is known, we are learning quite a bit about the genetic makeup of all North Shore Rainbows through the Steelhead Genetics Project. It is very typical to see kamloops reported in the creel prior to seeing steelhead for the temperature reasons noted above; and we see this to a degree in the chart with kamloops being reported in March prior to steelhead
- We can't know precisely when MMT will be reached each year, but there is a developing picture as to how long our typical "pre-MMT" phase lasts. We'll illustrate this in a different way below, but short of rapidly warming stream temperatures and limited or no snow-pack during this phase, our pre-MMT period seems to last anywhere from four to five weeks. Generally we see an average 10%+/- of our total creel being reported during this period. This is fairly consistent across all regions and years with the exception of the Upper Shore; more about that below
- Post-MMT we saw our typical 7-10 day magical period where both steelhead and kamloops seemed to be everywhere
- The week of April 16th brought us a good bump in flow (see above daily chart), which brought in subsequent runs of fish, particularly kamloops. Once MMT is reached, flow appears to take over as the primary influence on subsequent up-bound migrations of adult fish although as the daily chart shown earlier demonstrates, significant drops in stream temps can change things in a hurry
Lower Shore Historical Data
With a total Lower Shore sample size of 2899 rainbows reported to creel over 8 years, we have enough annual data to put together an overall picture of the Lower Shore runs. The Lower Shore Creel Survey - All Time chart below illustrates the total numbers of all rainbows (kamloops + steelhead) reported by week for all years in the Creel Project: 2010-2017.
Generally speaking, the Lower Shore migration can start any time after the week of March 12th, typically having wrapped up by the week of June 4th. This is the general framework, but remember that those dates are inclusive of the very earliest migration start and latest migration end dates from a historical perspective. Usually it is closer to an April 2nd through May 20th timeline on the Lower Shore.
Within that framework however, the developing picture shows a strong Lower Shore historical peak migration week of April 16th through April 22nd with 697 rainbows reported. These dates closely agree with and are independently supported by DNR trap numbers from the French and Knife river. As of the last Juvenile and Adult Trap Supplemental Report, the single date with the greatest numbers of rainbows sampled over time at the trap has been April 18th. The practical application from a steelhead fishing perspective is that if you are trying to plan a trip for any given year, April 16th through the 22nd is likely your best starting point. If you were a bookie, that would be your Lower Shore money-week.
The catch is that we all know year to year fluctuations in weather, flow and stream temperatures are unpredictable which makes predicting when the runs will start, peak and end also unpredictable. However, understanding where MMT actually falls in the current year helps you maximize your chances at steelheading success regardless of which region of the Shore you fish.
Finally, the peaks illustrated during the weeks of April 30th and May 14th represent historical "late" and "latest" migration year peaks still apparent in the overall data. These should become less apparent over time, just as shifts in the peak week may also develop in the future due to a number of factors.
The Lower Shore Creel Survey Means chart below shows you average numbers of rainbows reported by week for all years in the Creel Project: 2010-2017.
Same concepts as outlined above in the All Time chart. Strongly defined peak the week of April 16th where we are averaging 87 rainbows reported annually. Historically we are averaging 362 rainbows reported to creel annually on the Lower Shore.
The last of the Lower Shore data incorporates the DNR combined French and Knife Trap numbers. This chart illustrates the reported numbers of both steelhead and kamloops captured by trap and seine during up-bound migration. We have included the average stream temperatures and actual average flow for Knife River by week of trap. One quick note regarding the depicted temps: To better illustrate against the large scale steelhead and kamloops numbers, we multiplied average temps by 10; so the index stream wasn't really 380° F at the point of MMT, it was 38° F. The weekly flow average however was in fact about 450cfs.
Several items of note: The chart illustrates to a degree the differences in steelhead and kamloops with regards to migration and spawning temps. Recall that kamloops exhibit a slightly lower threshold than steelhead. You can generally treat MMT temps as the same for both steelhead and kamloops for fishing purposes. We just aren't as concerned with the finer biological distinctions between the species when we are out there flinging yarn, spawn, waxies or flies around. Just be aware that the differences are there because this can mean all the difference between fishing and catching, especially in cold water on the front-end of the runs.
Recall also that the kamloops returns depicted here come almost exclusively from French River. The French is smaller and tends to warm more quickly than other area streams. This means it will typically reach the threshold earlier than streams such as the Knife, so you tend to see more of a separation between the steelhead and kamloops return peaks as a result of the combined effects of lower return/spawning thresholds and earlier warming. The week of April 2nd 2017, DNR Fisheries seined some 600+ Kamloops out of the lake pool, many of which had been in there for an extended period of time already, so some of that presence wasn't necessarily related to 2017 migration proper.
You also begin to get an idea of just how quickly steelhead will move up a given system. If you look at the Lower Shore creel peak vs. the Lower Shore trap peak, you'll note the trap peak is slightly earlier. There are some other factors at play here: The trap captures steelhead at the point in time they attempt to pass that location on the Knife, you could only wish to catch fish with the efficiency of the trap. The anglers have to find the fish, then get them to bite which always accounts for some delay. Even so, if you were to look at the trap data, a large number of fish were captured between April 13th - 16th, so the limitations of our chart illustrator have a little bit to do with the apparent difference between the Creel and Trap peaks. The difference in true peaks between creel and trap isn't quite as large as it appears to be is what we are saying. Also, the kamloops are off-limits at the French once they enter the stream. It is not until they are spawned, transported, released, then find their way back into other Lower Shore streams that they become available again to stream anglers. This also accounts for some of the shift in creel vs. trap peaks for kamloops.
All-Time Knife Trap numbers. Ok, not quite... We don't have exact data points for all years of trap data; where that is the case, we have relied on the reported dates and numbers from the DNR spring fishing report. This is a historical chart showing rainbow returns to trap along the Lower North Shore. As with our other historical charts, they are not a prediction of future runs, but they do provide a framework to begin understanding the question of, "When do the fish run?" This data is very useful as a comparison point to see whether our Creel Project data has validity, and helps to substantiate other findings. There are a couple oddities here which don't really warrant going into related to the reporting format and limitations in data-point plotting. We have also plotted the long-term flow averages for Knife River for your consideration along with total numbers of fish sampled by week. Total sample size is 15,267 rainbows trapped
(Nearly) All-Time French Trap numbers, same historical charting comments as above but note the slightly earlier kamloop peak. We plot the long-term flow averages for the old Sucker River Gage (now disabled since the 2012 flood) for your consideration along with total numbers of fish sampled by week. Total sample size is 27,437 rainbows trapped.
Our first Mid Shore reports started coming in on April 3rd, seven days after our first Lower Shore reports. Our last submission was on May 20th for a total of 47 days although there were still fish being observed and caught in Mid Shore streams well after the 20th. Total numbers of fish reported were as follows:
- Steelhead: 340 and 105% of 2016 totals
- Kamloops: 18 and 150% of 2016 totals
- Brook Trout: 54 and 96% of 2016 totals
Mid Shore was once again Mid Shore; it has been schizophrenic since day one of the Creel Project and continued to be so in 2017. Both the Mid and Upper Shore effectively launched at roughly the same time as Lower Shore. While this is uncommon for Upper, we do see this from time to time with the Lower and Mid Shore regions. What's unfortunate across board for the 2017 Creel Project is that we lost a significant amount of data during prime time, and we see it in the Daily Chart between April 11th and April 16th.
One of the oddities we see from year to year with Mid Shore is that our index stream is the largest of all the Mid Shore Streams. Since it typically warms to MMT several days after most other Mid Shore streams, it is the only chart where MMT lags significant increases in creel. The lag time is typically small, about two days here as indicated by the red arrow on the 10th and when the index stream hit MMT on the 12th. All of those other smaller streams reach MMT several days up to a week prior to the index stream, and the creel report plots typically reflect that. This is the reverse of Lower and Upper Shore. If we had annual access to and used Knife River temps, we would likely see the same thing given Lester, Sucker, French and the others warm to MMT more quickly drawing fish, anglers and subsequent reporting.
As with Lower Shore, we lost or had to throw out data during the initial stages. Even so, Mid Shore reported numbers were quite strong. As with both Lower and Upper Shore, most of our data throw-out's due to missing/stripped out dates occurred between April 13th - April 16th, and this is reflected in all regional trends; it wasn't due to a lack of fish, that is for sure. Strong correlations in trend to flow increases on the 19th - 21st of April with some crazy numbers posted. I remember plotting the data thinking, "What in the heck am I DOING sitting here crunching numbers?!?" By the time I even had a chance to think about getting out, stream temperatures had tanked between April 26th - 28th along with reported numbers. Again, having a thermometer and a willingness to do some boot work paid off for those who did report as they were able to find slightly warmer water and more active fish.
From May 15th through the remainder of the run, those who were willing to grind it out as opposed to chasing turkeys or walleye were finding aggressive drop-back fish. Water temperatures cooperated and remained at levels where late season thermal stress and low dissolved oxygen levels was not as great a concern. This is not true most years and it is something to consider when fishing the tail end of the run. The problem with late-run fishing is that warmer water contains less dissolved oxygen. Imagine running a sprint with duct tape over your mouth, or running that same sprint at 8,000 feet elevation in the mountains. You just can't exchange oxygen efficiently enough to fuel you brain and your muscles, and this is the danger presented to steelhead with respect to potential added mortality. It is something to consider when fishing late and yet another good reason to carry a thermometer.
In the Mid Shore Weekly chart, you can see strong early numbers just in front of MMT, again due to large index stream size compared to smaller streams where most of the early reporting was coming from. The week of April 23rd got quite cold with average stream temps dropping below 40°F and a significant corresponding drop in creel. Strong returns and creel reports again the week of April 30th as stream temps rebounded and flows dropped into more reasonable ranges. From May 14th on we were into that tail-end of the Mid Shore run. Things had pretty well wrapped up once Mid Shore average temperatures reached 53-56° F.
Mid shore All Time: As we've stated previously, the Mid Shore has always been a bit of an enigma. The first peak remains from one of our earliest-recorded run years. People were fishing and reporting in mid-March across the shore, but we anticipate this peak will become less evident with time and data.
The April 16th - 22nd peak has us a bit perplexed. We assumed that in 2017 we would see this peak reduce somewhat, but were surprised to find that it actually grew proportionally to the 04.30 - 05.06 peak. Our best guess at this point is that this has more to due with the geographical range of the Mid Shore in comparison to Lower Shore. The Mid Shore reporting beat encompasses everything from the Stewart to just north of the Baptism. The Stewart and Silver are geographically much closer to Lower Shore streams when compared to all other Mid Shore streams; both as a group and from an MMT perspective. They are far more closely associated with Lower Shore timing than with Mid Mid and upper Mid Shore timing where most Mid Shore streams are concentrated. (My apologies to all English Teachers for that sentence, but you get the point) The Stewart in particular also draws quite a few fish. A question and data exercise we added to our list this year was to figure out a way to plot Stewart and Silver numbers as a unique group as well as to compare them against Lower Shore and Mid Shore beats. It probably will not be possible since we do not ask for individual stream names in reports, and we also follow the Creel Clerk Beat regions of the Minnesota DNR for our reporting. We only ask for anglers to submit fish caught by region, so we never know precisely where the fish are being reported from other than Lower, Mid or Upper Shore; it's probably best to keep it that way although we are darn curious...
Total numbers of fish reported to creel by week for all years in the Mid Shore creel at left.
Mid Shore Creel Survey Means shows the average numbers of rainbows reported to creel by week for all years in the Creel Project: 2010-2017. Long term Mid Shore average rainbows reported now 247 annually.
Our first Upper Shore reports started coming in on April 5th, 2 days after our first Mid Shore reports, and 9 days after our first Lower Shore reports. Again, 2017 was one of the years where the entire shore launched at roughly the same time. Our last submission was on May 21st for a total of 46 days. There were some "Unofficial" reports coming in after the 21st which accounts for the trend extending into June on the daily chart. The period of active creel reporting was again limited both by our reporting page woes, as well as the annual limitation on how far people are willing to travel and fish. We just don't see the annual numbers in the Upper Shore creel as we do in Lower and Mid. Additionally, the inland fishing opener typically occurs during this period, turkey hunting is still going on etc. All but our most hard-core steelheaders and anglers who live on the Upper Shore have usually turned to other pursuits by this point in the year. This lack of reporting despite fish still being present in the streams has had an effect on what the Upper Shore Creel Project has looked like since 2010, particularly on the tail-end of the Upper Shore run. Total numbers of fish reported were as follows:
- Steelhead: 81 and and 85% of 2016 totals
- Kamloops: 5 and 125% of 2016's total of 4 kamloops
- Brook Trout: 46 and 209% of 2016 totals
Temperatures bounced around a bit at the point of Upper Shore MMT as well as flows. Melting remaining snow-pack adding cold water to the streams had more to do with this than anything else, but you can see the delay in creel trend post-MMT because of it. Once the majority of that cold meltwater had flushed out of the system and average stream temps began to climb, the trend took off. Same issue with reporting problems around tax day as the Lower and Mid Shore.
The Upper Shore Weekly shows an extended peak in creel, and fishing on the Upper Shore was very good considering low angler numbers during that roughly three-week period. Here too we see the run effectively ending when average stream temps reach the 53-56° F range.
Upper Shore All Time. We're still trying to figure out what the overall upper shore picture looks like based on the Upper Shore All-Time and Means. One of our biggest problems is the lack of good data on the back-side of the Upper Shore run. The chart might lead you to believe that fishing drops off precipitously during the latter part of the run; but the real problem is we don't have enough data to have any meaningful insight into just how long things last on the Upper Shore. One other possibility we are considering is that due to the prevalence of small streams on the Upper Shore, warming occurs so rapidly overall during the end of May that steelhead finish spawning quickly, then leave as average water temperatures reach the 53-56° F range. Either way, these are reasons why we consistently request reports for that region and time period specifically year after year.
One other very good reason to encourage both creel reports, and more importantly scale sample collection, is the Steelhead Genetics Project. Samples from all regions including the Upper Shore have begun yielding a wealth of information regarding populations of naturalized steelhead. Upper Shore steelhead have been shown not to be fully immune to genetic introgression of kamloops genes, so having this information will help shape and guide steelhead management policy.
Upper Shore Creel Survey Means: Lower all-time average numbers evident by week due to less people fishing the upper shore along with lack of data on the back-end. The chart probably shouldn't drop off like that, but again we don't quite know; perhaps that is really it. Long term Upper Shore average rainbows reported now 110 annually.
Shore-wide Historical Creel Survey
The Shore-Wide Creel Survey - All Time represents the unified picture for all regions of the shore: Start, peaks, end and total numbers of fish reported by week. It's the "big picture" chart. Each Region's annual means are nested within the chart including the earliest and latest creel reports. This provides you with an "At a glance" reference for North Shore steelhead returns. Each peak from left to right beginning with the large April 16th - April 22nd peak represents creel peak for Lower, Mid and Upper Shore. The Upper Shore peak is not quite as evident due to low late-season reporting from that region.
Coasters and Steelhead
Since these fish are making their living in and around near-shore habitat, it would make sense for them from a survival-strategy standpoint if they took advantage of other species in a similar fashion, and we are beginning to think spring steelhead and kamloops offer them just such an opportunity.
When we looked at our coaster data, we saw a signature in that creel data which looked awfully familiar. These fish are more than five months out from spawning, so we began to wonder what they were doing in the streams, what else might be going on, and why the familiar signature in the data?:
We next plotted the regional and shore-wide coaster data, then plugged in the regional peaks from the historical rainbow data. While we don't get exact correlations, it does get more interesting when you compare the regional coaster peaks with the regional historical rainbow peaks:
Lastly we simply plotted the Shore-wide historical charts for brook trout and rainbows together. It is difficult to ignore the correlations in the overall return period as well as the strong correlations to Mid Shore peak rainbow return to creel. There are also some subtleties here to consider. While it is not as apparent in the chart below, if you compare both Lower and Upper Shore regional brook trout peaks to their respective regional rainbow peaks, you'll see the correlations. The Mid Shore peak correlation as shown is very strong. Part of the thought here is that with the lower prevalence of coasters in the creel on the Lower Shore, but much higher in the Mid and Upper Shore, this may (or may not), lend some insight into coaster populations and densities, and how they might be eking out a living in Superior's oligotrophic environment by utilizing other species spawning runs as a food source.
The last item to note is that we are not using this spring brook trout data for fishing purposes. It has however become a way to use a seemingly unrelated type of data to potentially understand more about the steelhead. If the premise holds true, and coasters are taking advantage of free-drifting steelhead eggs as an alternative high-value food source, it would make sense that coaster catch might correlate with peaks in steelhead returns. Or maybe it's just a fluke, only time will tell.
Information Regarding Stream Temperatures and the "Major Migration Threshold"
In the early days prior to the Creel Project, we were already asking some specific questions regarding steelhead and kamloops. When you look at much of the non-technical literature and fishing articles, one of the primary influences on steelhead movement mentioned is flow (discharge). From a biological perspective, migratory fish like steelhead and salmon are programmed so to speak to run on high flows when available. High flows offer these migratory fish the best chance at bypassing obstacles and barriers. It also provides the best chance to reach the upper regions of any given watershed. These uppermost areas typically offer the best habitat, not only for spawning, but the habitat necessary for juvenile fish to survive: Clean gravel, oxygenated water, proper temperature ranges, woody debris, abundant food, deeper hydraulic structure, critically-sized substrate, protection from predators etc.
The prevailing non-technical explanation was essentially that flow was the be-all, end-all in steelhead fishing and steelhead movement. That held true, except for when it didn't which was quite a bit on the North Shore based on all of our other data. Even more specifically, the flow adage did not hold true at all during the early portions of the season when the water was cold. Something was going on in the North Shore environment that appeared to be different with respect to the question of "When do they run?" Anecdotally we were also interested in getting at the science behind what MS calls "Magic 40". Magic 40 is a rule of thumb term MS uses to describe a number of things but from a steelheading perspective, it relates specifically to the effectiveness of bait vs. fly vs. hardware presentations along with overall fish activity in a given stream at given temperature ranges.
After re-combing through the DNR technical literature, we found references to the temperature range at which steelhead typically begin up-bound migrations in very high numbers. This seemed to explain why you can have ideal flows at low water temperatures, but not be catching let alone finding fish early in the run. What we did at that point was to use all of the available Minnesota DNR trap data to create charts showing both the total returns by temperature, as well as the returns which fell in the gray area (early run so to speak) we were interested in. That gray area corresponds to early-season, cold water temperature conditions; or what we now call, "Pre-Major Migration Threshold Returns".
There are a total 21,578 rainbows in the DNR Trap samples below. The MMT returns are a pretty consistent 10-11% which predated our own MS Creel Data numbers but closely agree. Peak returns occur in the magic 40 range, and 89-90% of adult fish begin up-bound migrations after MMT is met. Note the slightly lower return temperature threshold with respect to the peak exhibited in the kamloops data.
Given the above data, it appeared to answer the question as to why early season (read cold water/pre-MMT) numbers anecdotally appeared low regardless of flow conditions. It also appeared to explain why in warmer/post-MMT conditions, steelhead seemed to behave and follow the accepted rules of flow with respect to the North Shore.
Once we had that information, we designed a way to analyze the regional creel data in the context of the temperature numbers. Despite a much smaller sample size of 5,666 rainbows, the results are nearly identical to the DNR Trap data.
What you see depicted below are each region's total creel returns plotted by week and normalized for what we call here "Zero Week". The zero week represents when that particular region reached and maintained the major migration threshold temperature for each year in the creel. All returns falling in the pre-MMT temperature range are depicted separately as well as a rough depiction of when the streams hit magic 40. Note that the pre-MMT and post-MMT percentages largely correlate with the independent DNR Trap Data. The one exception is the Upper Shore, and we'll discuss that in a moment.
The one oddball here seems to be the Upper Shore. We'll need more data to understand this, but we have a hypothesis as to why pre-MMT creel returns are relatively low for the Upper Shore in comparison to all other regions. Recall that kamloops in general have a slightly lower migration and spawning temperature threshold as compared to steelhead. What we think is going on here is that kamloops are driving the higher pre-MMT percentages on the Lower and Mid Shore simply because there are far more of them present in those regions, again as a result of the kamloops stocking protocols to limit genetic introgression. Since there are far fewer kamloops present in the Upper Shore region from year to year, the pre-MMT or early return numbers and percentages should in theory be lower based upon known migration and spawning differences related to temperature in kamloops.
The by-product of these charts is that if you wanted to know what a typical run looks like on a year to year basis, this is very probably it for each region: Roughly four weeks of pre-MMT run activity with 10-11% of adult rainbows returning to the streams and available to steelhead anglers. Once MMT is met, there is a 7-14 day period of high rainbow presence and activity in the streams; your best chance at steelheading success. Overall, the run lasts approximately 5 additional weeks from MMT, with subsequent pushes of fish largely driven by increases in flow. The total availability of rainbows in any given region then would be in the neighborhood of 28 days of peak fishing activity on a year to year basis with some overlap. The actual period of availability is longer although in-stream population numbers are much lower on both the front and back-end of the run.
We should know at some point how valid this run progression hypothesis is, but it will take a number of years and lots more data. If this is in fact valid, our long-term historical charts for each region should begin to look more and more like their respective run progression charts. The other proof will be in the pre-MMT percentages. Fluctuations in kamloop numbers should theoretically show corresponding increases in pre-MMT percentages during high return to creel and trap years, and decreases in pre-MMT percentages during low kamloop return to creel and trap years. Pre-MMT steelhead numbers have yet to be fully analyzed, but we think those should be on the order of 3-6% of total creel. We are tracking the steelhead only MMT progressions, but we want larger data-sets before posting.
Overall, given the picture we are developing using your data in the Creel Project, the steelhead season in Minnesota is something like 60+ days on average with about 20-25 days of peak fishing. If you're willing to follow the migration as it develops from Lower Shore through the Mid and Upper Shore, it's a pretty sweet deal for a steelheader.
MS Creel Project Raw Numbers by Year
Quick chart on the raw reported creel numbers for each species by year. Keep in mind our reporting troubles, we know the 2017 numbers were in fact much higher. We are only reporting what we officially recorded and not the toss-outs:
And there you have it, 2017 in a can. We at Minnesota Steelheader hope you found this informative, interesting and useful. From all of us at MS a BIG thank you! Without your participation in the MS Creel Project none of this is possible.
Best of luck and good fishing-