09-09-2019, 07:06 PM
[#0000FF]Last week we had a couple of questions and some discussion on the wiper/shad continuum, etc. I sent an inquiry to Chris Penne (DWR) asking about the status of the 2018 Willard Report and their current observations of the lake balance. As always, he responded with some good info. Thanks, Chris.[/#0000FF]
Yes, I survived the summer and am glad it's nearly fall. I'm sorry to report, but we went so long on the Willard data from 2018 that we're now planning on conducting our fieldwork for the fall and then making a two-year report for 2018-2019. Since we haven't completed the report for the data from 2018, I can't say for sure where we are at on wiper numbers, but I'd guess were pretty similar to the past couple years, which is to say we're at about half the numbers that we would like to have. We should be on the upswing now and gaining in numbers. I like to keep the graphs and figures in our reports to covering no more than a ten year period, but one of these days I'll have to put in a larger figure spanning about 20-years of time. What you see when you look at the long term picture is that the wiper population is a more like a sine wave that is continually rising and falling. Most animal populations are like that, but the trend line for the wiper population has a higher amplitude than most of the fish we deal with (i.e. - the highs are higher and the lows are lower). My observation is that we go up in numbers for about 3-4 years and then down for about the same before coming back up again. I'm thinking most of this has to do with riding big year classes of fish for about 3-4 years before they get fished out and then when those fish leave they make room for the new fish. So we were on the downward trend 2015-2017 and I'm thinking we should be on the uptick now. Fishing was actually quite good in 2015 and 2016, but keep in mind the numbers we are looking at also include fish that are from about 8-12" and mostly aren't going to be caught or observed by anglers until they get bigger - so our observations will be different than what one would see from fishing alone. We've also had a excellent stocking this year and were able to stock about 150,000 fingerlings in August, which should give us a boost. There is one kink that is worth bringing up too that we're just going to have to wait and see on is how the walleye stocking will affect recruitment of wipers over the long term. We've had good success with the walleye program the past four years and there is definitely a possibility that the rising walleye population could make it harder to get the wiper fingerlings to recruit, whether that be through competition or predation. We're keeping our "eyes" on that and will adjust our walleye stocking numbers if we see it is negatively impacting the wiper population. Anyway, probably a long winded answer on the wiper numbers, but wanted to add some perspective there.
On the shad, yes we've observed the same thing with the shad numbers being lower this summer, at least relative to the past couple years. We also saw quite a few spottails in the seines we pulled for shad too. This may be a good sign that our predator numbers have caught back up with the shad numbers after the water levels came up. While the wiper numbers have been down, the walleye numbers have been coming up fast, we've got the great catfish numbers and then we've also had some early indications that we've got a good year class of crappie growing right now too. I would imagine the cooler and more stormy spring weather helped us out a bit too and led to lower survival of those earlier cohorts of shad.
Chris
[signature]
Yes, I survived the summer and am glad it's nearly fall. I'm sorry to report, but we went so long on the Willard data from 2018 that we're now planning on conducting our fieldwork for the fall and then making a two-year report for 2018-2019. Since we haven't completed the report for the data from 2018, I can't say for sure where we are at on wiper numbers, but I'd guess were pretty similar to the past couple years, which is to say we're at about half the numbers that we would like to have. We should be on the upswing now and gaining in numbers. I like to keep the graphs and figures in our reports to covering no more than a ten year period, but one of these days I'll have to put in a larger figure spanning about 20-years of time. What you see when you look at the long term picture is that the wiper population is a more like a sine wave that is continually rising and falling. Most animal populations are like that, but the trend line for the wiper population has a higher amplitude than most of the fish we deal with (i.e. - the highs are higher and the lows are lower). My observation is that we go up in numbers for about 3-4 years and then down for about the same before coming back up again. I'm thinking most of this has to do with riding big year classes of fish for about 3-4 years before they get fished out and then when those fish leave they make room for the new fish. So we were on the downward trend 2015-2017 and I'm thinking we should be on the uptick now. Fishing was actually quite good in 2015 and 2016, but keep in mind the numbers we are looking at also include fish that are from about 8-12" and mostly aren't going to be caught or observed by anglers until they get bigger - so our observations will be different than what one would see from fishing alone. We've also had a excellent stocking this year and were able to stock about 150,000 fingerlings in August, which should give us a boost. There is one kink that is worth bringing up too that we're just going to have to wait and see on is how the walleye stocking will affect recruitment of wipers over the long term. We've had good success with the walleye program the past four years and there is definitely a possibility that the rising walleye population could make it harder to get the wiper fingerlings to recruit, whether that be through competition or predation. We're keeping our "eyes" on that and will adjust our walleye stocking numbers if we see it is negatively impacting the wiper population. Anyway, probably a long winded answer on the wiper numbers, but wanted to add some perspective there.
On the shad, yes we've observed the same thing with the shad numbers being lower this summer, at least relative to the past couple years. We also saw quite a few spottails in the seines we pulled for shad too. This may be a good sign that our predator numbers have caught back up with the shad numbers after the water levels came up. While the wiper numbers have been down, the walleye numbers have been coming up fast, we've got the great catfish numbers and then we've also had some early indications that we've got a good year class of crappie growing right now too. I would imagine the cooler and more stormy spring weather helped us out a bit too and led to lower survival of those earlier cohorts of shad.
Chris
[signature]
