MN DNR fish surveys

A question for discussion.
How much faith does everyone have in the DNR’s lake surveys?
I have seen many lakes as I look for information on the fish quality that don’t make a lot of sense.
Lakes that are stocked with fish that don’t show up on surveys.
I realize not all fish travel where nets are set, but if that is the case, maybe nets should be set where fish are.
Or maybe they should put in a large disclaimer that the survey is not really very accurate.
Or is it that there stocking efforts are pretty much a waste of time and money?

I’ve done them before when I used to work for the DNR. They are accurate based on the fish that are sampled.

They place nets in similar areas because they’re trying to be as consistent as they can. They don’t always do them at the same time of year as the previous survey because they don’t have the manpower or time, so they do them when they can.

Make sure you take note of the date the survey is done. Some of them are a few years old and it’s likely the fishery isn’t the same for one reason or another.

Some of them surveys are way old.

I look at them for a general idea and if it trips my trigger I’ll go fish the lake.

Gimrius, why would you give up a cushy job like that.

I always thought there were some species that were harder to net than others. Largemouth, for example always seem to be under represented. I’m guessing the DNR is looking at the data as a sample, not an estimate of the total population. They’re looking for long term trends.

SR

I use them as a starting point to which lakes I want to try and fish. There are certainly many more variables that will effect the results fishing wise and just because a fish survey says there aren’t any 14 inch crappie in a lake doesn’t mean it’s true.

Steve Root wrote:

Largemouth, for example always seem to be under represented

Yes you’re right as LMB aren’t sampled well using nets. They need to be electrofished.

mahtofire14 wrote:

and just because a fish survey says there aren’t any 14 inch crappie in a lake doesn’t mean it’s true.

Absolutely true. But if the largest crappie sampled a year ago was only 10 inches it’s unlikely there are very many, if any, 14 inchers present.

glenn57 wrote:

Gimrius, why would you give up a cushy job like that.

It was interesting but quite honestly I found something better.

gimruis wrote:

<div class=”d4p-bbt-quote-title”>Steve Root wrote:</div>
Largemouth, for example always seem to be under represented

Yes you’re right as LMB aren’t sampled well using nets. They need to be electrofished.

<div class=”d4p-bbt-quote-title”>mahtofire14 wrote:</div>
and just because a fish survey says there aren’t any 14 inch <strong class=”ido-tag-strong”>crappie in a lake doesn’t mean it’s true.

Absolutely true. But if the largest <em class=”ido-tag-em”>crappie sampled a year ago was only 10 inches it’s unlikely there are very many, if any, 14 inchers present.

Depends on what netting/trapping strategy was used.

Yes, I do. The best walleye fishing I ever had for quantity and quality (14″-22″) was on a lake that was just sampled a year or two before. By the summary of the lengths of netted fish and tacking on 2 inches per year they should be nice keepers and they were. For 3 guys, caught over 100 fish for the morning. ~20 doubles and 5 triples. Flipping in fish up to 22 inchers after we had our limit. Went through 2 scoops of fatheads, couple dozen crawlers and a dozen leeches. It was interesting because jigging outfished rigging at least 10:1. This was on a Sunday of opening weekend on a west central MN lake. Dead calm, bright sun, 10-15 feet of water on a mid-lake hump.
This would be my best open water fishing memory if there ever is a post for that.

So how old can a survey be, before it becomes worthless?
Why is it the stocking history will show regular stocking for a species and they don’t show up in the following survey?

Tom schmitt wrote:

So how old can a survey be, before it becomes worthless?
Why is it the stocking history will show regular stocking for a species and they don’t show up in the following survey?

Too many factors to answer the first question Tom. Predation, lake conditions, and angling pressure all play a role. Certain species of fish are targeted and harvested more than others too.

The second question we don’t have an answer to. Just because fish are stocked doesn’t mean they will automatically be sampled. Sampling is only a small portion of fish present at a moment in time.

Thanks all!

Netguy wrote:

Yes, I do. The best walleye fishing I ever had for quantity and quality (14″-22″) was on a lake that was just sampled a year or two before. By the summary of the lengths of netted fish and tacking on 2 inches per year they should be nice keepers and they were. For 3 guys, caught over 100 fish for the morning. ~20 doubles and 5 triples. Flipping in fish up to 22 inchers after we had our limit. Went through 2 scoops of fatheads, couple dozen crawlers and a dozen leeches. It was interesting because jigging outfished rigging at least 10:1. This was on a Sunday of opening weekend on a west central MN lake. Dead calm, bright sun, 10-15 feet of water on a mid-lake hump.
This would be my best open water fishing memory if there ever is a post for that.

I’ve been there get done fishing think you have it all figured and ready to jump on the pro walleye circuit and 3 weeks later get schooled by the fish lol so humbling use serveys all the time info is better then no info

“The second question we don’t have an answer to. Just because fish are stocked doesn’t mean they will automatically be sampled. Sampling is only a small portion of fish present at a moment in time.”

That whole thing has to be tremendously complicated. Back in the 1980’s, the DNR was dumping millions of Walleye fry into Lake Waconia every year. We caught very few walleyes in those days but the Crappie fishing was awesome. They finally started stocking fingerlings and had better success.

SR

Steve Root wrote:

“The second question we don’t have an answer to. Just because fish are stocked doesn’t mean they will automatically be sampled. Sampling is only a small portion of fish present at a moment in time.”

That whole thing has to be tremendously complicated. Back in the 1980’s, the DNR was dumping millions of <em class=”ido-tag-em”>Walleye fry into Lake Waconia every year. We caught very few walleyes in those days but the Crappie fishing was awesome. They finally started stocking fingerlings and had better success.

SR

which is kind of why I ask the question.
It seems some of this stocking is a waste of time and money.

Do you think some of these smaller fertile lakes in the southern third of the state be better managed as big perch lakes?

Troy Hoernemann wrote:

think you have it all figured and ready to jump on the pro walleye circuit and 3 weeks later get schooled by the fish

I’ve fished other lakes that were “loaded” with walleyes and only caught a couple over many hours. The lake was also full of forage. That’s the time you should have been here 2 months later after the forage got eaten down and the walleyes would bite.

Tom schmitt wrote:

It seems some of this stocking is a waste of time and money.

Most of our lakes other than the bigger ones with natural reproduction would be completely void of walleyes if we didn’t stock them. Very few water bodies are able to keep up with harvest relying solely on natural reproduction of walleye. Unless of course you required them to be catch and release only but I highly doubt that would occur.

gimruis wrote:

<div class=”d4p-bbt-quote-title”>Tom schmitt wrote:</div>
It seems some of this stocking is a waste of time and money.

Most of our lakes other than the bigger ones with natural reproduction would be completely void of walleyes if we didn’t stock them. Very few water bodies are able to keep up with harvest relying solely on natural reproduction of walleye. Unless of course you required them to be catch and release only but I highly doubt that would occur.

Or more so the fact they don’t naturally reproduce in most lakes to sustain a fish able population.
Swerving off topic here but like others have said some information is better than no information, but yeah if the survey was done 20 years ago it is probably not worth much.

Ripjiggen wrote:

Or more so the fact they don’t naturally reproduce in most lakes to sustain a fish able population.

Ya that’s what I was getting at thanks

One thing to note- Those studies don’t exist for the sole purpose of helping anglers know how many of what types of fish are in a lake. their main purpose is to help the DNR monitor long-term management solutions to achieve specific goals. The numbers and lengths at any given time are just a fun bi-product, and they’re public information to use as you’d wish. I’ve had good luck targeting a specific species on some new lakes that I’ve found on lakefinder, and others where it looked like a no-brainer, but struck out completely. It’s just a small piece of the puzzle. It will at least give you a good idea of if it’s worth the effort, but you gotta learn the lake.

ThunderLund78 wrote:

ut you gotta learn the lake.

So right. Another lake I targeted was loaded with fish after a walleye rearing pond flooded into it. The downfall was the water clarity was 20 ft. Good luck catching them during the day!!

Years ago I was thinking of developing an app that would allow users to search the online/public database more easily. I think it would be awesome to be able to sort the lakes by survey year and then sort those lakes by species surveyed and then sort those lakes by the size distribution. The only way I’ve found to do that is lake by lake. I’m surprised someone hasn’t done that yet.

for example….I wanna know ten lakes in Ramsey county that were surveyed for crappie in the last two years with a high CPUE and a size distribution with upper tails in the 14″s.

j

I’ve been wondering if the DNR would give me their most recent test netting database for all lakes so I could sort/search how I preferred.

On a somewhat related note, is this no longer listed in the LakeFinder? Last couple times I’ve tried using it, there was a whole new interface and couldn’t locate the fish surveys.

BigWerm wrote:

On a somewhat related note, is this no longer listed in the LakeFinder? Last couple times I’ve tried using it, there was a whole new interface and couldn’t locate the fish surveys.

If you’re using the mobile interface just click on the “summary” drop down and it is there.

J

This is how I use the survey numbers and stocking reports:

1) Targeting a species that is harvested regularly like walleye or panfish is a completely different ball game because the lake could have been hammered with a hot bite. For example, if the fall survey showed really good numbers of eating sized walleyes or 12 inch crappies but it got smoked in the winter. So going the following May I would not expect to see the numbers of those fish shown in the survey last fall.

2) Targeting a species that is not regularly harvested like bass or muskie. If a survey 3 years ago showed that there were 3 tiger muskies sampled over 40 inches, those fish are likely still present in the lake. If the previous fall showed an electrofishing survey that yielded a very high population density of largemouth bass, its safe to assume most of them are still there and and slightly bigger. So in this case, I am confident that my targeted species is still present in the numbers given.

This is just how I approach it and I’m only using it as an example. I did some surveys years ago and I target a variety of species now so the expectation needs to change based on the target.

JasonP wrote:

<div class=”d4p-bbt-quote-title”>BigWerm wrote:</div>
On a somewhat related note, is this no longer listed in the LakeFinder? Last couple times I’ve tried using it, there was a whole new interface and couldn’t locate the fish surveys.

If you’re using the mobile interface just click on the “summary” drop down and it is there.

J

Thanks!

They can be useful to see year classes but I always take them with a grain of salt. Bigger fish often aren’t sampled if they’re sticking close to the ground because they’re smart and don’t want to get caught in the nets.

You asked if much of the stocking is a waste of time and money-Yes&Yes But people demand it. To stock a lake with walleye that is full of small pike is just a waste, don’t think the very few big pike or skis are the problem-its lots of little small ones.