WDFW Fall Walleye Surveys in Washington

[Mike Schmuck]

We have finished our walleye surveys of Billy Clapp and Moses Lake and we move on, next week, to Potholes Reservoir.

Billy Clapp catch rates were similar to years past but Moses Lake catch rates averaged 35 walleye per net (22 per net in 2011). There were also a lot of small perch collected. The abundance of small perch in the nets, and in walleye stomachs is a likely cause of poor angler catch rates (and based on the complaints I heard angler catch rates were poor this year).

These are the highest catch rates we've seen since 2008 and only three years (2002, 04 and 07) have seen higher abundance of walleye in Moses Lake.

There seemed to be walleye all over Moses Lake but especially in the south end close to the outlets to Potholes Reservoir.

The final report will not be out for some time as it includes data from 5 lakes in Washington. Look for it around Christmas.

I also am unable to answer specific questions about these surveys since all the data have not been entered.

Mike Schmuck
WDFW
Warmwater Fisheries Program Biologist
Ephrata, WA

[Anglinarcher]

Interesting results Mike. I suspect that you are probably right on the catch rates. I have noticed it is hard to compete with the food mother nature provides. One way for anglers to overcome that reduction of bites when they are dealing with abundant natural bait is to offer the Walleye, or other predators, larger baits. Predators take care to get as much energy from every attack they make as they can. Bigger baits will offer this to them.

An abundance of small perch will mean larger Walleye in Moses Lake in the years to come.

What did Billy Clapp Walleye have in them? What was the average size you would guess you saw in Billy Clapp?

Thanks Mike.

[YellowBear]

Mr Schmuck.
I have a friend that lives on Moses and he had a couple of questions.
Could you tell us how many nets did you use?
Where did you set up to collect the data?
How many days did it take to get 300 fish?
Did you put the nets in the same areas as they had been in the past?

Thanks for your time.

[TerryBullard]

We have finished our walleye surveys of Billy Clapp and Moses Lake and we move on, next week, to Potholes Reservoir.

Billy Clapp catch rates were similar to years past but Moses Lake catch rates averaged 35 walleye per net (22 per net in 2011). There were also a lot of small perch collected. The abundance of small perch in the nets, and in walleye stomachs is a likely cause of poor angler catch rates (and based on the complaints I heard angler catch rates were poor this year).

These are the highest catch rates we've seen since 2008 and only three years (2002, 04 and 07) have seen higher abundance of walleye in Moses Lake.

There seemed to be walleye all over Moses Lake but especially in the south end close to the outlets to Potholes Reservoir.

The final report will not be out for some time as it includes data from 5 lakes in Washington. Look for it around Christmas.

I also am unable to answer specific questions about these surveys since all the data have not been entered.

Mike Schmuck
WDFW
Warmwater Fisheries Program Biologist
Ephrata, WA

Hi Mike,
Frankly I still can't get head around as to why it is necessary to capture and kill 300+ walleye from these lakes every year. I haven't done the math but that sure seems like a lot of breeding stock removed from the lakes every year. This year at The Potholes survey I saw some great walleye that I would love to catch next year but they were at the cleaning table and of course only those who helped clean the fish for you got the meat so, nothing useful was accomplished. I do feel the meat could have least went to the food bank and I do know that F&G were approached with that concept several years ago.
For the last 4 years I have tried asking questions to the F&G guys only to get snubbed out about the surveys. In talking with some of the managers at F&G in Olympia I get the impression that walleye are considered an invasive trash fish and would much rather see trout instead.

Currently I believe the surveys are bad for future walleye fishing and I have noticed a decline in walleye fishing over the years. I am hoping there is something you can say which will change my mind. I do have a lot of faith in F&G but I do think you are wrong in this issue. As I understand not one crawfish was found inside a walleye at Moses Lake. Moses Lake is intensely over populated with Rusty Crawfish to such an extent that they have been observed migrating over land in search of new waters. Rusty Crawfish are active all year regardless of water temp so, they are not the food source for walleyes as the survey showed.

Currently the Rusty Crawfish are just now starting to inhabit the Potholes and your walleye survey time would be better spent keeping tabs on them. They are a huge threat to all game fish and plant life as you should know. I would be very happy to give you any help you may need concerning crawfish. The managers in Olympia trust your decisions through your research, they have told me that directly.

Don't get me wrong I'm not trying to rag on you but I do find it upsetting when I see all those, what I call Game Fish and future generations going to waste.

Thank You.

[Mike Schmuck]

Mr Schmuck.
I have a friend that lives on Moses and he had a couple of questions.
Could you tell us how many nets did you use?
Where did you set up to collect the data?
How many days did it take to get 300 fish?
Did you put the nets in the same areas as they had been in the past?

Thanks for your time.

On Moses Lake this year we set 10 nets on day one. One was stolen overnight and we were only able to collect data from nine nets.

We work up all the fish at Pier Four just south of I-90 near the outlets. We work here because there is easy access to grass which makes net picking musch easier (less dirt and grime on the fish). We can pull our boat right up to the grass and dump the nets to be picked.

We collected 321 walleye on day one. We count the walleye into the boat as we pull the nets but we undercounted a lot of young fish as they were in with hundreds of perch in the small mesh end. We believed we needed two more nets to get the 300 walleye required. In those two nets we collected around 80 more walleye. Our total was around 400 fish in 11 nets. This is a rough estimate as I have not entered the data.

Each year we randomly select sites. There are 199 sites on Moses Lake. To ensure we sample all areas of the lake we break the lake into four sections and select an equal number of sites from each section.

We sample new locations each year unless we happen to randomly pick a site that was used the previous year. I am not sure which sites were used last year as I was not involved in the sampling.

Mike

[Mike Schmuck]

We have finished our walleye surveys of Billy Clapp and Moses Lake and we move on, next week, to Potholes Reservoir.

Billy Clapp catch rates were similar to years past but Moses Lake catch rates averaged 35 walleye per net (22 per net in 2011). There were also a lot of small perch collected. The abundance of small perch in the nets, and in walleye stomachs is a likely cause of poor angler catch rates (and based on the complaints I heard angler catch rates were poor this year).

These are the highest catch rates we've seen since 2008 and only three years (2002, 04 and 07) have seen higher abundance of walleye in Moses Lake.

There seemed to be walleye all over Moses Lake but especially in the south end close to the outlets to Potholes Reservoir.

The final report will not be out for some time as it includes data from 5 lakes in Washington. Look for it around Christmas.

I also am unable to answer specific questions about these surveys since all the data have not been entered.

Mike Schmuck
WDFW
Warmwater Fisheries Program Biologist
Ephrata, WA

Hi Mike,
Frankly I still can't get head around as to why it is necessary to capture and kill 300+ walleye from these lakes every year. I haven't done the math but that sure seems like a lot of breeding stock removed from the lakes every year. This year at The Potholes survey I saw some great walleye that I would love to catch next year but they were at the cleaning table and of course only those who helped clean the fish for you got the meat so, nothing useful was accomplished. I do feel the meat could have least went to the food bank and I do know that F&G were approached with that concept several years ago.
For the last 4 years I have tried asking questions to the F&G guys only to get snubbed out about the surveys. In talking with some of the managers at F&G in Olympia I get the impression that walleye are considered an invasive trash fish and would much rather see trout instead.

Currently I believe the surveys are bad for future walleye fishing and I have noticed a decline in walleye fishing over the years. I am hoping there is something you can say which will change my mind. I do have a lot of faith in F&G but I do think you are wrong in this issue. As I understand not one crawfish was found inside a walleye at Moses Lake. Moses Lake is intensely over populated with Rusty Crawfish to such an extent that they have been observed migrating over land in search of new waters. Rusty Crawfish are active all year regardless of water temp so, they are not the food source for walleyes as the survey showed.

Currently the Rusty Crawfish are just now starting to inhabit the Potholes and your walleye survey time would be better spent keeping tabs on them. They are a huge threat to all game fish and plant life as you should know. I would be very happy to give you any help you may need concerning crawfish. The managers in Olympia trust your decisions through your research, they have told me that directly.

Don't get me wrong I'm not trying to rag on you but I do find it upsetting when I see all those, what I call Game Fish and future generations going to waste.

Thank You.

To be clear, we rely on volunteers to get these surveys done in a timely manner. We have given the fish to the food bank in the past but that arrangement no longer exists. Many of the fish now go to a different charity.

It is necessary to kill 300 walleye so we can collect valuable biological information on walleye condition, growth, fecundity, and size structure of walleye populations.

The walleye population is not affected by harvesting 300 fish from the population. We remove much less than 1% of this population each year through sampling. It is akin to 300 anglers keeping 1 more fish over the course of a year. The angler harvest of walleye on Potholes and Moses Lake is incredibly low. Too many people feel (incorrectly) that catch and release is necessary to ensure good walleye fishing. Most of the walleye in these lakes die of old age, not harvest.

We have been doing these surveys since 2002 yet walleye populations continue to rise and fall based on biological parameters, not sampling. I have stated this on numerous occasions but it bears repeating: Catchability of walleye is not related to walleye abundance (except in obvious cases where there are no walleye). But in lakes with abundant walleye we don't see a rise in angler catch rates that corresponds with an increase in the population size. The most striking thing about this year's surveys was the number of perch in the nets (and walleye stomachs). A full walleye doesn't need to forage as much as a hungry one and when food is plentiful he doesn't need to forage for very long.

I'm sorry you were snubbed in Olympia but this has nothing to do with the question at hand. I'm sure there are people in Olympia who think that walleye are trash fish and would prefer trout, but again, this has nothing to do with this discussion, unless you are insinuating that we are trying to extirpate walleye. My job is to manage warmwater fish populations (bass, walleye, crappie, bluegill), I view all these fish as valuable resources for our constituents and work hard to manage them effectively.

I'm not sure where you get the idea that walleye surveys are ruining walleye fishing. They certainly aren't affecting walleye abundance. Walleye fishing last year on Potholes was excellent, and this in the 10th year of our surveys.

I'm not sure I agree with you that rusty crayfish are a detriment to fish populations. The bass and walleye in Moses Lake seem to love them and if they eat some aquatic vegetation I'm not sure that is a bad thing.

I also don't agree that the walleye collected are going to waste. We get a tremendous amount of information on these poulations that help us set harvest regulations.

[MarkFromSea]

I just want to say thanks Mike for your hard work and especially for posting info here that gives some added insight to warm water fisheries in E WA. I was one of those who tried catching walleye in Sprague a few years back and was unsuccessful. I look forward to giving Moses and Potholes a try some time. Roosevelt has been good to me at times. Keep up the good work!

[Mike Schmuck]

As I understand not one crawfish was found inside a walleye at Moses Lake. Moses Lake is intensely over populated with Rusty Crawfish to such an extent that they have been observed migrating over land in search of new waters. Rusty Crawfish are active all year regardless of water temp so, they are not the food source for walleyes as the survey showed.

Currently the Rusty Crawfish are just now starting to inhabit the Potholes and your walleye survey time would be better spent keeping tabs on them. They are a huge threat to all game fish and plant life as you should know. I would be very happy to give you any help you may need concerning crawfish. The managers in Olympia trust your decisions through your research, they have told me that directly.

Thank You.

Terry,

The invasive crayfish in Moses Lake and Potholes are Northern Crayfish, not Rusty Crayfish. Yes, they are very invasive and have become incredibly abundant in the past few years. We do find a lot of crayfish in walleye stomachs (and also bass). I don't know exactly how many we saw in walleye stomachs on Moses Lake this year but we have found a lot in walleye in years past.

We have no reason to believe that these crayfish will have a negative impact on any fish population in Moses Lake. There are a lot of smallmouth, largemouth and walleye that will eat these crayfish. I do agree that we should monitor these populations and this is something I was doing a few years ago on Moses Lake. We collected several Northern Crayfish for researchers from UW. It may be a good idea to continue with this sampling to monitor their abundance over time.

Mike

[racfish]

Occaisionally on Lk wa. I see a smaller boat with Uof W fishieries on it using a net. I wonder if they do the same as you do Mike? I always wondered why they netted. Do you know of other programs like yours on the Western side of the state?

[Mike Schmuck]

No, not for walleye. There are other agencies that use gill nets but I don't know what they may be targetting.

Mike

[YellowBear]

Most of the fish in Moses and Potholes die of old age and not harvest.
They must die out in the middle of the lake and sink, like they did at Sprague.

The Walleye population is not affected by harvesting 300 fish.
Walleye deposit 50,000 to 300,000 eggs.
In the past 10 years the WDFW has killed off over 5 million fry.

[zen leecher]

I've met a few people lately who complain about "things" but do little to find a solution or improve it. I participated in both the Moses Lake and Potholes surveys to gain information about walleye, walleye locations and walleye feeding habits. There's also info to be gained on lake whitefish. The filleting of fish is the easy part. The hard part is being down on hands and knees removing fish from the gill nets.

[Rosann G]

I too helped with the fish surveys on Moses Lake, Potholes and also Billy Clapp this year and it is very interesting to see what all is looked at and recorded about all the fish caught in the nets. Anyone wondering about it should come out and help next year. Zen leecher is correct, the hard part is being down on your hands and knees figuring out how to get the fish and crawdads out of the nets but it's fun and interesting. Mike's right, there was an incredible amount of small perch and also other small fish in the nets so to me that says the lakes are healthy and the big fish are reproducing but what do I know.
Thanks Mike for posting all the info about what was caught and also answering all the questions that have been posted here.
Sorry we didn't figure out who each other was Zen, it would have been cool to put a face to your handle.
Rosann

[Mike Carey]

Most of the fish in Moses and Potholes die of old age and not harvest.
They must die out in the middle of the lake and sink, like they did at Sprague.

The Walleye population is not affected by harvesting 300 fish.
Walleye deposit 50,000 to 300,000 eggs.
In the past 10 years the WDFW has killed off over 5 million fry.

True, when you put it this way it seems like a lot of fry, but if you continued your argument to included all the fish in the system and the eggs/fry they release you would be talking billions of fry, and your 5 million fry number would be put into perspective.
I.E., what is the estimated population in Moses/Potholes? Let's say 3,000 fish (just a number, I don't know). Based on your argument those fish have released 500,000,000 fry. (300 is 10% of 3,000, 5 million is 10% of 500,000,000).

So Mike, do you have an estimate as to how many walleye are in these two lakes?

[MotoBoat]

Most of the fish in Moses and Potholes die of old age and not harvest.
They must die out in the middle of the lake and sink, like they did at Sprague.

The Walleye population is not affected by harvesting 300 fish.
Walleye deposit 50,000 to 300,000 eggs.
In the past 10 years the WDFW has killed off over 5 million fry.

True, when you put it this way it seems like a lot of fry, but if you continued your argument to included all the fish in the system and the eggs/fry they release you would be talking billions of fry, and your 5 million fry number would be put into perspective.
I.E., what is the estimated population in Moses/Potholes? Let's say 3,000 fish (just a number, I don't know). Based on your argument those fish have released 500,000,000 fry. (300 is 10% of 3,000, 5 million is 10% of 500,000,000).

So Mike, do you have an estimate as to how many walleye are in these two lakes?

Mike C, I read where Mike S indicated the 300 walleye to be less than 1% of the total population.

Most of the fish in Moses and Potholes die of old age and not harvest.
They must die out in the middle of the lake and sink, like they did at Sprague.

The Walleye population is not affected by harvesting 300 fish.
Walleye deposit 50,000 to 300,000 eggs.
In the past 10 years the WDFW has killed off over 5 million fry.

So, in response to YellowBear. I was going to base my math on that 1%. Based on that, your numbers could be extremely conservative. Good job Mike C, you beat me to the response I had considered posting. If 300 are used in the study, and is 1% or less of the total population. Then 10% x 300 = 3000. Then 10 x 10% x 300 = 30,000 fish population x 50,000 and 300,000 respectively = 1,500,000,000 - 9,000,000,000 eggs and possible fry spawned into the lake. Remove 5 million from those numbers for a "fair" comparison.

Why not subtract Walleye fry removed from the Walleye caught by anglers, in that equation? You know, to use fair numbers.

Mike C or Mike S, check my numbers and repair if needed.

[Augwen]

With the numbers and all those zero's...it is sounding like one of the political debates

[MotoBoat]

With the numbers and all those zero's...it is sounding like one of the political debates

Probably a good idea to verify those guys numbers........too!

Or live with the end results.

[Mike Schmuck]

To add even more to the mix......

Not all the fish removed were females. Approximately 1/2 the fish collected were females, a percentage of those were not mature and may have never survived to reach spawning age in any event. I don't have the 2012 data entered yet but in 2011 only 39 mature females were collected during FWIN, the remainder were small, immature fish.

The arguments I hear are often similar to the arguments used by anti hunters who assume that every deer, elk, duck, goose, grouse, bunny, quail, pheasant.... not killed by hunters will go on to produce copious amounts of progeny that will give us a bounty of game around every corner.

Remember that there is a harvestable surplus in every wild population that will die, either of disease, old age, predation, etc... Yes, we removed x number of adult females from this population, but again, this is an incredibly small percentage of the population. If it weren't we would see reductions in population size every year in these populations.

If I had to put a number on the population size in Moses Lake or Potholes I would estimate it to be between 120,000 - 200,000 fish including young of the year. This is a rough estimate based on net abundance and fish per acre.

Doing the math here: 300 fish is between .15 and .25 % of the population. Natural mortality rates are much higher than this. What is even more unfortunate is that angler harvest rates are much lower than what these populations can endure.

Click on the following link for more information on mortality rates for fish populations.

http://www.google.com/url?sa=t&rct=j&q= ... AF6B15y4xw

For anyone who is truly interested in learning more about the work we do I encourage you to volunteer. We had volunteers work with us this fall and it was great. I think they all came away with a better understanding of the fish community in these lakes.

Mike S

[MotoBoat]

Thanks for that insight, Mike S. Of the estimated 120,000-200,000 adult and juvenile walleye to inhabit Moses Lake or Potholes. What would your estimate be for a population of Mature Female Walleye?

[zen leecher]

39/300 is the proportion of the sample taken for adult females. That percentage times 120,000 to 200,000 is the approximate number of total adult females.