Post Season Analysis

Well, I shouldn't say, "Post Season" quite yet. There are fish around if you know where and when to look. I do have some intesting graphics assembled now that the DNR creel and fishing reports are done for the spring. MANY thanks to the hard-working folks at DNR fisheries, they rarely get enough public credit; usually they are just getting an earfull....

One of the most useful ways I've found of looking at all the numbers has been to use a weekly format as it does a few things:
1. It smoothes out any wild fluctuations in the numbers
2. It allows comparisons between different years along with different State's data
3. It's a bit more intuitive and easy to grasp
Without boring you further with a whole bunch of mental gymnastics used to produce the charts, here's how the Lower Shore combined trap numbers looked through May 20th (Click Thumbnail for larger image):



The blue/green lines are the total returns by week, the yellow is the average Knife River discharge in CFS by week and the black the Knife ice-out date reported by USGS.

If you want to see just how strange a year it has been, here is 2010 compared to the long-term return averages by week. Warning, it's going to look like I was on crack when I produced the chart, but bear with me:



Note that 2010 ice-out occurred nearly three weeks earlier than normal. In fact, the steelhead return peak was in full swing during the time ice is usually going out on Lower Shore tribs. Return peaks occurred about two weeks earlier than the historical average as well. 2010 Kamloops returns are skewed by a couple days, but it's related to the way the graph works, or more accurately doesn't work; it's not a terribly sophisticated graphing program. Close enough though...

And finally, the Lower Shore creel survey numbers:



I've added stream temps to the creel graphics and for good reason. DNR Fisheries has been quietly reporting for some time now that temperatures closely approaching or exceeding 40°F are a critical factor and influence on initial upstream movement of Kamloops and Steelhead. I've since gone back and run numerous years returns against mean temperature and flow, and the correlations are too strong to ignore. Remember, we're talking about initial upstream movement only with regards to the magic 40°F average. Once that occurs and fish move upstream in numbers, it appears that flow once again takes over as the main factor in upstream movement.

Now, that doesn't mean we don't get early forays of fish into the streams at say 33-36°F because we do. I've even seen them running through meltwater over the ice to get to a hole; were really talking about significant numbers of fish. Coincidentally, magic 40°F also seems to be the point at which flies begin to be increasingly effective. Below that bait seems to outfish flies by a wide margin. Keep these things in mind on the North Shore and you'll be a better and a more successful fisherman.

Last but not least, the Mid and Upper Shore creel surveys:



Note that early fishing success/higher numbers of fish caught really didn't get going until temps hit the 40°F average.

Last item- Don't let the low numbers of Upper Shore fish throw you. The Upper shore simply has lower numbers of fishermen/women out and about at any given time so the overall numbers of fish caught are generally lower and there are less folks to survey.



Regards & Good Fishing!
NMF

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