Fisheries Management 101

[Moose1am]

Been reading some post from fishermen who were talking about fish conservation and it make me stop and think for a minute. Last night I read an older (1 year old) newspaper article about my favorite lake. It was about the 4 year old White Crappie in my favorite lake only being 8" long. Not sure if you guys know how long a 4 year old crappie should be as I can't recall but according to the fishery biologist a four year old fish that is only 8" long is STUNTED. It should be a lot bigger in a normal IN lake. And I would think that fertile lakes would have bigger and longer 4 year old crappie. I am thinking that this is an average lenght and weight for the Patoka lake fish that are captured in the fish surveys. They surveyed the upper reachs of the Patoka River part of Patoka Lake with two types of nets. Drop nets and gill nets I think. The DNR drops them into the water for 24 hours and captures anything that runs into the net during that time period. How or why the sample these spots I dont' know. But the point being is that when you have a lot of small fish in a lake there is a reason for this. Having lots of small fish and not very many big fish means that there is not enough food for all the small fish to grow and become big fish. The Growth Rates are low or slow.

How do you know that your lake has stunted fish? Well ask the local authorities to see if they have any sampling data on the fish in your lake and find out if they are growing ok or not.

Our fisheries biologist recommends that we remove lots of the smaller fish right now. By lowering the numbers of smaller fish we leave those that are left with more food per fish. Wish we could figure out how to increase the food supply for the fish too. Would love to have more fish and all of them be bigger slabs but my lake just won't support that right now.

Many factors go into determining the growth rates of fish in lakes. So talk to your fish and wildlife guys and find out what is going on in your neck of the wood.

Sometimes it pays to keep the small fish.

This past year I started fishing a new area and was catching lots of 8" fish and throwing them back thinking I was doing good. But after talking to the DNR guy that was conducting the fishing surveys for the Fisheries Biologist I figured out that it was not good to throw these little fish back. I was giving them away at first but then I decided that I would clean and eat them. Now this was in early spring that I first started crappie fishing here. By fall the fish I were catching were starting to get bigger. I was catching more and more 10" + fish. I was fishing in a new spot and in a differnet pit but it's connected to the other pit by a 36" diameter culvert and the two pits are not more than 50 yards apart and only seperated by a roadway.

Now if your fish are growing fine and have normal growth rates it may pay to toss the little ones back. But if the lake is full of stunted fish then keep a few. Heck if you don't want to clean and eat them give them to some kids that fish the banks when you get back to the ramp. Where I fished this summer there were always some kids fishing for bluegills or catfish along the bank near the ramp. They were excited to take home some crappie.

[unknown 5]

I give away most of my fish. There is a couple that fishes by the marina near my home. The man is blind but loves to fish. I have filled their catch bucket with crappie lots of times.

[Big Zig]

Moose - that lake has shad in it doesn't it?

The people involved in the fishery here in Pa don't have a clue. They work with the, "stock it and lock it" theory. The fact that our fishery is fueled by the put and take trout program is doing nothing for our warm water fishery either.

[Moose1am]

I guess that my point earlier was that each lake is different and it helps to talk to the DNR guys to find out more about your particular lake that you fish. They talk to lots of fishermen and conduct creel surveys to help them establish the fish populations. They can look at captured fish and determine growth rates by looking at the fish's scales under the microscope. They can measure the chemicals in the lake's water and come up with some type of plan to help build up the fish populations. At least that is the theory. So try and talk to the DNR guys and find out what is going on. We may not understand all they do is all I was trying to say. We need to work with them and try to help them do a better job. I know that IN has hearings where they gather input from the public on a lot of their projects. I Hope that other State DNR of Fishery Management people do that also.

I think it's best to let the Wildlife Guys do their best. Lots of guys don't understand what they are trying to do including me. But I guess we have to trust someone to try to manage the fish and game for us. So far they seem to be trying hard to do a good job with the tools that they have here in IN. I know that their budgets are not great and it's hard to do a good job without any good funding.

Yes Patoka Lake has Gizzard Shad since 1996. Before that they never found any Gizzard Shad in the lake when they conducted sampling of the fish. Somehow gizzard shad got extablished in the lake and have overpopulated the lake. Most of the biomass in Patoka lake since 1996 has consisted of Gizzard Shad. Their numbers are huge. The IN DNR introduced Stripers to try to control the Shad. Cold winters can also help reduce the shad population if the waters get cold enough for a long time. We don't have any Threadfin Shad in Patoka which is too bad as they don't grow as large and make better food for the crappie and bass. Only two lakes in Southern IN have Threadfin shad and that is Gibson Lake and Turtle Creek which area both heated lakes. The power companies dump hot water into these lakes and then use the lakes to cool the water down before it empties into the Rivers. This prevents what is called Thermal Pollution of the rivers. Wouldn't want to heat the water and then have a problem and have the water in the river get cold all of a sudden in the winter time. All the fish would have been up in the hot water and then suddenly been exposed to cold water and died. This way the water in the river cools and heats more gradually and the fish can take that better than sudden temp changes. And during the summer time the water needs to be cooled before it's put in the river or all the DO would outgassed and the fish would suffer from not only hot water but lack of Oxygen in the water.

Moose - that lake has shad in it doesn't it?

The people involved in the fishery here in Pa don't have a clue. They work with the, "stock it and lock it" theory. The fact that our fishery is fueled by the put and take trout program is doing nothing for our warm water fishery either.

[Big Zig]

Find the source of those shad Moose.................check the pockets of those DNR guys you want to help. You are just starting to dust of the glaze to a much larger political hole.
I agree 100% with you - help the people that are there to improve the system. There's only one problem: Unless you come up with the funding, the system isn't going to change.

I've had my eyes opened to the real Pennsylvania Fish and Boat Commision recently. I was like you, in that I wanted to support an agency that was in place to help the sport. Guess what? It's a smoke screen.
Take some time when you're surfing to look at the allocations of funding in your state. Where it's coming from, and where it's going. You might just be surprised. Hopefully you will tell me it just isn't so.

Pa. is in deep financial trouble right now in regards to facility improvements and repairs. Yet they continue to feed an 80 million dollar cold water fishery with a 46 million dollar income. Guess where the rest of the funding comes from...................remember those shad?

Keep looking Moose, the truth is out there. I didn't want to believe it either, but why do you think I've been asking questions on the board about other state's fisheries and how everyone handles creel limits?

EDIT: Just for clarification, the DNR does do a much better job at mangement and maintenance on the waterways they manage (vs. the PFBC). Political motivation is still the directing force with that organization, that will never change.

[Minus 1]

Moose:
I'm going to put my 2 cents worth on this. All my life,I've been told that if you don,t keep your crappie, bluegills, and bass thinned out in a lake or pond ( whats the difference between a lake or pond ? ) you would end up with inbred and stunted fish. I was a firm believer of this until last fall .I know a lot of ponds that all you can catch are stunted 6 or 7",paper thin crappie. Same for bass and bluegill. Three years ago,we fished a watershed lake,(about 50 acres)and consistantly caught 12 to 14" crappie,2to5lb. bass and nice bluegill..A disgruntled land owner open up the gate valve at the dam, and forgot about it. We didn't find out about it was pretty well dry. The fish were trapped in a ditch below the dam.We saved a lot of them and put them in other ponds. Also filleted a lot of them.While it was dry, some of the guys took a trackhoe in and dug some channels, made some small islands,built some A frame crappie condos out of 3 to 4" willow posts.They went to some of these stunted fish ponds and caught the crappies, bluegills,and bass by the 100s every day for a week or more. I think they ended up putting 2600 of these stunted crappie in the newly filled watershed lake. I told them they were wasting their time ,that they were stunted and wouldn't get any bigger.Out of curiosity, we fished it last fall. We consistantly caught 10 and11" crappie. The bass were in the 2 to 4 lb. range,the bluegill were slabs for Indiana gills.It totally blew my mind that the stunted fish grew like they did and a lake could bounce back that quickly.
Ledhed :

[CrappiePappy]

Most DNR people will tell you that a lake (pond?) of 25 acres or less is not big enough to support Crappie ... unless a big majority of the biomass is bigger predator fish (and even then it's a management nightmare). Your 50 acre lake/pond is big enough to support and hold a decent population of Crappie - so long as the food source is adequate to sustain them, and there's enough other predator fish to keep their numbers in check. Large Bass, Channel Cats, and other predator fish that can & will feed on the smaller Crappie will help keep the Crappie population thinned out. But, you will also have to continue to remove some, yourself.
It is very possible for the Crappie to grow quickly from stunted to keeper size ... as long as there's enough "food" in there to support the numbers. But, they will revert back to stunted fish if their numbers get out of hand. The Bass, Bluegills, and Crappie are all probably feeding on each others fry and smaller sized members ... and as long as the balance of numbers & size is maintained, you may have a productive watershed.
If "some of the guys" went to all the trouble and expense to do all that contour work and cover additions - it may benefit them to contact the DNR or Wildlife Officer of that area, and have the lake checked out. They may be able to suggest ways to manage, or even offer to help manage the population of the lake. This probably would have been better done when the lake was nearly empty, and before fish were returned to it ... but, what's done is done, so it may be up to you and "the guys" to micro-manage the lake. That is - if it's a "private" lake. If it's state owned or state managed ... I'd let the state take over the management. It's in their best interest, money wise, to manage the lake for quality fish ... because that means more money in the coffers (for them) and more tourist dollars for the state. (and don't be shy about telling them so !!) .........luck2ya ...........cp

[Moose1am]

Hey Ledhed:

Fish get stunted because they each can't get enough food. Once they are put in an environment where they can get adequate food supplies they will grow bigger.

We scientists use a term called "CARRYING CAPACITY" to describe a habitats abilty to support the life that lives in that Habitat. The more food or nutrients, cover and shelter that you give an animal the happier it will be. Crappie need an adequate supply of microorganism and minnows or small fish to survive and prosper. They need clean water to grow also. If you put fish in water with a very low pH then they will not thrive or grow well. But you put them in good water and they can take off and really grow better.

Each lake is unique. Each lake has different chemicals dissolved in the water and different bottom types and surrounding area. Each lake has different water draining into it. Each lake has different Air Pollution being emitted around it these days. When I was working in the Environmental Chemical Analytical Laboratory we tested many different parameters of the water samples we were charged with testing. We tested ground water around the local coal mines and we tested surface waters in this area. We tested the drinking water for bacteria as well. I guess what I am saying is that there are so many variables that no two lakes are identical. Each is unique and different charasteristic.

This means that fish in one lake may grow faster or slower. And lakes are dynamic and can change over time. Populations of fish are dynamic as it life in general. The predator prey relationships can make a lake different from other lakes. The contour of the lakes bottom can make or break a lake for certain fish species. Some fish need special types of bottoms or depths to spawn successfully.

Genetics plays a roll as well but it by itself will not always be the main factor in how well a fish grows.

You can take a fish with the best genes and starve it and it will not grow to it's potential.

One thing that length limits do perform is to save the genes of fish that have the biggest growth potential. The fish can spawn a few years before it's taken out of the fish population by fisherman and it's offsprings can carry on it's genetic material to the next and future generations.

The bottom line is that we should try to let the Experts do their job as best as they can. They may not always get it right but I feel that they know a lot more about it than I do and I am willing to listen to them and give them a shot at managing the fisheries for us.

[Moose1am]

Big Zig:

The Shad were most likey put in the lake by some bass fishermen. Shad helped the Bass Fishing a great deal. Bass can grow big and fast eating Gizzard Shad. It's the bluegills that suffered when the Shad population exploded. Indiana DNR was managing Patoka Lake to provide a good bluegill fishing lake and now the bluegill fishing is way down.


Man I understand what you are saying. I worked for government for 7 years at the local level and found out all about how that works.

I have friends that work for the IN DNR that I went to College with and they are some of the smartest people that I have ever met. Whether they can do thier job without interferece I don't know. Last time I talked to my friend he was not happy. He had left the Indiana DNR once before but returned after being gone for a few years. He did complain about not earning enough money to feed his kids. Which is why I chose not to go into that field myself. I almost went the same way he did and took three of the same classes that he took. That is how we became friends in college. We took wildlife biology classes and stastitics together. And we took the same Computer Science Class and a few other of the same classes. So I have somewhat of an idea on what he did in school and what he was taught. I was studying preveternary medicine before I changed majors. So I got a pretty good background in the hard sciences. It's harder to become a vet than to become a doctor (they say). Doctors only have to lean to treat one species while vets learn to treat many species.

The thing I have found is that many of the people that are elected to govern are not aware of the sciences and especially the widlife sciences and it's up to my old friend to try to educate them on this subject. That is not an easy task. Luckily my friend has a lot of allies. Who are they? Well you me and all the hunters and fishermen and women out here that demand good hunting and fishing opportunities. It's our tax dollars that fund a lot of what the DNR does. I know that they don't have the funding to do it all perfectly but they try to do the best job that they can with the money that they are given.

I recommend that you visit the Indiana DNR or the Tennesse DNR or the Kentucky DNR or many of the other states DNR and see what they are upto. I don't know much about what goes on in PA. I have cousins that live there and they like to fish. My uncle and Aunt lived near Vally Forge for most of their life and ended up moving to Ft Meyers FL. to retire. We use to fish with my uncle in the Atlantic Ocean on his cabin Crusier and had a lot of good times fishing off the coast of New Jersey. I spent a few weeks up there and stayed at his cottage right next to the bay.

Politics effects everything and we just have to work with it to get the job done as best we can. Nothing is perfect.



EDIT: Just for clarification, the DNR does do a much better job at mangement and maintenance on the waterways they manage (vs. the PFBC). Political motivation is still the directing force with that organization, that will never change.[/QUOTE]

[LBM]

Overcrowding and stunted fish.

The way I have been told to look at this situation is that any given body of water will support X number of pounds of fish (what ever that is). If that body of water will support say 200 hundred pounds of fish then it would be able to support 4 – 50 lb fish or 8 – 25 lb fish or 100 – 2 lb fish and so on.
Usually when people fish a over crowded pond and they will keep the larger fish they catch and return the smaller fish to the pond. As time goes on all they will be catching is the stunted smaller fish.
Years ago in high school I experienced this while fishing a pond for bass. The first year we discovered and fish this pond we brought home several of what we considered nice sized bass. Back then they were probably at the largest 3 lbs but we considered them nice. The next summer we caught a few but not as many. The third summer we finally determined that we wouldn’t be fishing that pond any more since all we caught were the small bass. It wasn’t until years later in a college course where it was explained about a given body of water supporting a given number of pounds of fish that I realized what had happened.

After that whenever I was fishing a overcrowded pond with friends I would suggest to them to toss the smaller fish out on the bank and release the larger fish. Usually they wouldn’t do it because they just couldn’t – it just didn’t seem right to do that. I tried to tell them they would be feeding the coons, coyotes, foxes and hawks and helping to improve this particular ponds fishing in the long run.

Just my two cents on this subject.

Good fishing