Mille Lacs hooking mortality

[otter]

fishnpole wrote:
Well, then, JJ, I’m just going to have to do a real “scientific” study to prove that killing thousands of spawning fish doesn’t hurt the fish population.

But first, I’ll have to drink the kool-aid so I can get as stupid as the people that think it doesn’t matter.

Its called North and South Dakota. They’ve been fishing the spawn for years. I pulled many limits in April over there. Coincidentally not one problem with reproduction.

[fishnpole]

otter wrote:

fishnpole wrote:
Well, then, JJ, I’m just going to have to do a real “scientific” study to prove that killing thousands of spawning fish doesn’t hurt the fish population.

But first, I’ll have to drink the kool-aid so I can get as stupid as the people that think it doesn’t matter.

Its called North and South Dakota. They’ve been fishing the spawn for years. I pulled many limits in April over there. Coincidentally not one problem with reproduction.

Point taken, otter, but coincidentally they don’t have thousands of fish being taken during the spawn by Wisconsin gill netting camps for the last 17 years, either………
https://www.youtube.com/watch?v=UuTioulExv8

[BrianHoffies]

NOBODY has ever said netting was the only issue on Mille Lacs. However not fixing the netting issue makes as much sense as building a three story house without a foundation. With the nets allowed during the spawn nothing else can work.

[fishnpole]

deadgooses wrote:

JJ wrote:

As I’ve encouraged for years, then build studies that refute the science the DNR is presenting. This is a much better way to state a case, than the same old complaining, with nothing but anecdotal evidence to support your claims.

Standing up and screaming that the science is wrong, without presenting any scientific alternative, is not only pointless, but it hurts your cause by turning people off.

This is the important part. Claiming FACT that the 10% number for hooking mortality based on your numbers, 3 floaters out of 2000 fish caught. As JJ said, anecdotal evidence is just that without a real study being conducted. The fact that you live on the lake and fish it 250 days a year means nothing without hard evidence. As was said before, not all dead fish float to the top, some swim down to the bottom and die. Unless you put a tracker on every one of the 2000 fish you catch, you have no idea what the hooking mortality is. Nor does the DNR, but at least the DNR is running studies to try to nail down the 10% number.

I realize the lake management is jacked up because of the netting, too many big fish, bad hatches of forage fish, etc., but complaining and spewing stories is not going to change anything. Anecdotal tales of fish decline isn’t going to alter the thinking of the people that can make change. You need scientific evidence, in writing, in order to make this change. None of that has been provided at this point.

These are points well taken from both of you. Unfortunately, as was with the case of the Windermere study, it took 55 years to study the long term effects of gill netting. http://aquaticcommons.org/4627/1/CPaxton.pdf
The damage will be done to the fishery that will be irreversible in only a few more years. Fortunately, we DO have Mother Nature to help us, as we did in 2013-14.
I’m not saying that there aren’t some excellent fisheries biologists working on studies right now. Pat Schmalz, in my opinion is one of these for the MN DNR. I’ve spoken with Patrick on many occasions about his work with Mille Lacs. Here’s an excerpt of a study he did on spawners per recruit: “There is a fundamental conflict between harvesting fish and conserving their biomass. Managers mediate this conflict with regulations that control fishery methods and amounts of harvest. In most recreational fisheries, aside from closed seasons, the precise control of fishing effort is difficult to achieve because fisher entry into a managed area is often unlimited and because effort can be influenced by both direct and indirect factors.Choosing the best fishing regulations is also complicated by a need to jointly regulate and accommodate the desires of different user groups who share the fishery. Regulations may need to account for (1) low-consumptive uses of fish populations that occur from catch-and-release fishing by recreational anglers and/or (2) both tribal subsistence and commercial fishers.”
https://www.researchgate.net/publication/290473941_Visualizing_Trade-Offs_between_Yield_and_Spawners_per_Recruit_as_an_Aid_to_Decision_Making

[fishnpole]

Research on the subject is as wide and varied, as you can imagine. The reasons for this are many times, like in the case of Mille Lacs, biased and political.
Length‐limit regulations and promotion of catch‐and‐release fishing have become increasingly important management approaches for recreational fisheries. We review‐studies on catch‐and‐release (hooking) mortality gathered from the existing fisheries literature and from a survey of fisheries management agencies in all 50 states, the U.S. government, all Canadian provinces, and selected academic and research institutions. We identified hooking mortality estimates for 32 taxa. Most studies dealt with salmonids, centrarchids (especially black basses, Micropterus spp.), and percids (especially walleye, Stizostedion vitreum). Within and among species, differences in percent mortality were reported in association with bait type (artificial vs. natural), hook type (number of hooks, hook size, and barbs), season/ temperature, water depth (depressurization), anatomical location of hook wound, and individual size. Although most hooking mortalities occur within 24 h, the use of initial plus delayed mortality provides a more complete estimate of mortality. Single hooks (especially when used in conjunction with natural baits) resulted in higher mortalities than treble hooks. Environmental conditions (notably high water temperature and low dissolved oxygen) are important to overall mortality related to hooking, playing, and handling.
Estimates of size- and sex-specific gear selectivity are important for making informed management decisions. Sex specific selectivity curvesmay be needed for two-sex statistical catch-at-age models when information about sex ratios in the catch is unavailable. We used data from three tagging programs in Minnesota and Wisconsin to estimate the size- and sex-specific selectivity of angling and spearing for Walleyes Sander vitreus.We estimated capture selectivity (the relative catchability of each component of the population) and harvest selectivity (the combined effect of capture selectivity and the decision to retain or release a fish from a given component). These components are of interest because (1) the hooking mortality of released fish contributes substantially to total mortality, so that it is important to know how harvest and release vary by size; and (2) capture selectivity is likely similar across lakes, such that data from other lakes may provide information on capture selectivity for the lake of interest, while harvest selectivity is lake specific. Estimates were obtained using generalized linear models to determine the significance of the individual and interactive effects of length and sex on selectivity. Angling capture and harvest selectivity were both greater for females than males of every length. In contrast, spearing harvest selectivity was greater for males. For both sexes, harvest selectivity for angling and spearing peaked at around 400–450 mm. The capture selectivity of anglers peaked at 350–375 mm. The interaction between sex and size was significant for capture selectivity for angling, with the sex effect for small fish being less than that for large fish. Above 400 mm, spearing selectivity did not appear to vary with length for either sex, but at lengths below that it was lower for males.

[fishnpole]

Now, with all that being said, the summer meeting of the Walleye Technical Committee came up with this:
“Mille Lacs continues to experience poor survival beyond age 1 without a clear explanation of why or what can be done about it. Understanding walleye dynamics is confounded by spiny water flea, zebra mussel, and Eurasian water milfoil infestations, reduced nutrient loading and increased water clarity, increasing temperatures and reduced Tullibee abundance, as well as increased abundance of northern pike and smallmouth bass. Ten million OTC-marked (eggs
collected from lake) were stocked this spring to help quantify natural reproduction. The walleye fishing has been good on Mille Lacs this year but it is restricted to catch and release only and no
night fishing (10:00PM-6:00AM). The restrictions are intended to protect the 2013 year-class which is the only reasonably strong year-class in quite some time.”

With all their research, they STILL aren’t coming up with any conclusions.

But it’s NOT the nets?

[Joehere]

[Joehere]

Except,possibly,respectful interaction (as the foundation). per BH post.

[fishnpole]

Sorry Brian. You’re right, of course. You posted while I was writing all that and I didn’t see your post from the posting page..

[snow]

quote:
Point taken, otter, but coincidentally they don’t have thousands of fish being taken during the spawn by Wisconsin gill netting camps for the last 17 years, either………
https://www.youtube.com/watch?v=UuTioulExv8

Further,for those chimming in the last couple years mille lacs didn’t have a walleye spawning bio mass crash until the netting took hold by the mid 2000’s,by 2012 the spawning bio mass went from 3.3million in 2000 to under 1.5million in 2012.

Pass the koolaid fishpole!

[Author]

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