Lower Shore Creel Numbers as of 05.06.2011

Here are the latest Lower Shore Creel Numbers for 05.06.2011

As you can see, the Lower Shore based on creel numbers appears to have peaked. DNR studies show that peak return typically occurs once stream temps maintain 40 degrees overnight, and you can see that has occurred as well. I just haven't had time to chart the trap numbers but it likely shows the same thing.

However, just because it likely has peaked doesn't mean that fishing is done on the Lower Shore. We'll still have fish returning for some time as well as spawned-out fish dropping back out of the tributaries. Not to mention the Mid and Upper Shores are still cooking. There's still a lot of fishing to be done...


Couple items- There have been some questions regarding how to arrive at the numbers shown on the charts. I apologise Zinger, I just hadn't had the time to get in a response to your questions from the previous blog entry, so here goes:

Whenever you see a chart that has a daily reporting format as in the April 26 blog post, there are a couple things to keep in mind. The flow and temperature values reported for that day are an average of all the readings taken throughout the day except for the maximum temperature where depicted. They are in all cases though a daily reported value.

The issue with flow is that normally it's much higher than the numbers being reported for temperature or fish returns whether they are creel or trap numbers. If I put flow at actual scale of 400cfs for example, then creel numbers are 20 fish and the average temp is 41, the lower numbers for temp and creel are all squashed together in a way that makes seeing the important relationships impossible. This is why you'll see a notation in the legend indicating flows have been divided by 10 and then plotted. It's still accurately depicting what flows are doing, but more importantly you can actually see the more subtle temperature, flow and run relationships. My problem is sometimes I copy a chart to make it easier to update some new info and forget to update the X and Y axis labels. That probably confuses the crap out of people and I apologize for it...

With the fish numbers it gets a little trickier. The issue, and I think this is what you were getting at Zinger, is that while the flow and temp values are daily values - in other words I have an actual number for each day shown - the creel and trap numbers are only reported every few days. If I depict the number reported for the day it is reported, it shows up as an isolated data point with no relationship to the previous or next reported number. You'd just see a dot and all you can tell is that it's higher or lower than the previous dot and the next dot, like this:


Generally what I do to make the chart a little more intuitive is to then connect the dots like this:


All the computer is doing to draw the line is interpolating a point between the actual reported data points. That's where it gets tricky because it looks at first glance like there are fish being trapped each day. That's the case in reality, but the DNR is only reporting the totals trapped every few days, so I don't have a daily figure. All you can really say then is that on 04.18 the Knife trap had zero fish in it. On 4.21 they had 134 fish in the trap. What you can't say is exactly how many fish came in on the 19th and 20th. Again, all I can do is plot the actual data for the day it's reported. Daily flow and temp data I have, not the case for trap and creel numbers. But, you still get a good sense of what's going on if I connect the dots as it were.

Which gets us to the type of chart posted at the beginning. The daily values are great for seeing relationships between flow, temperature and fish movement. However the weekly format/values better illustrate exactly where the run is at. The only difference between the two is that all the trap or creel numbers are added up for a particular week, and then plotted, so it's a total for the dates shown. In the above chart, I haven't posted what weeks 10-15 are, but you can figure it out because the peak of the Lower Shore steelhead return is week 16 or April 16-22. Which means that week 15 was April 15-21 etc.

Because the trap and/or creel numbers are cumulative for that particular week, you can see that total Lower Shore steelhead creel for week 16 was 88 fish. Kamloops appeared to have peaked out in week 17 (April 4.23-4.29) at 55 fish. Kamloop numbers are a little trickier though because even though they might be kept by the fisherman reporting to the creel census clerk, the ones getting trapped all get returned to the lake, which means they might get trapped again, or potentially caught and eaten. I'm not saying this skews the numbers, only that it's something to be aware of.

In the end, all this crazy mathematical contortionism just serves two purposes:
1. The daily numbers give you a feel for what's going on more or less real time.
2. The weekly averages such as in the chart above tell you roughly what stage the run is at and from there you can draw your own conclusions about conditions elsewhere.

The charts do serve another purpose, but that's a discussion for another time. Right now it's time to get out and fish.
Regards-
NMF

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