Responsible Harvest

[Kuiakua]

I guess I should introduce myself quick first: I'm Whopperhead's brother, Randy, and have gone out diving with him a few times, but I am just a novice diver. I have been lurking this site since last summer when I met a few of you at the apalooza.

I just moved to Madison this spring and have gone out diving a few times around here. In those few times out I have seen some of the biggest bluegills (10"+) and some very nice crappies (13"?) and perch (12"). My question for all of you, after seeing some of the big stringers of big fish that have been posted here, is: how do you practice responsible harvest to ensure that the quantity of big fish is not decimated over time? I'm definitely not being critical of those keeping the big fish, but if someone more knowledgeable than me could explain how to harvest fish with minimal impact to the size and numbers of the fishery, I would feel a lot better about keeping a couple of meals. In my current mindset, eating a 10"+ bluegill makes me feel pretty guilty because where I have been fishing for the past 11 years (Twin Cities, MN) that is a VERY rare fish.

I know that I could just shoot smaller fish to make myself feel better, but I was just wondering about the impact of everyone keeping limits of big fish, even though it is legal.

...not hatin'...just wondering...

 

[Whopperhead]

Unirdna......Your expertise?

 

[kalin]

Hi Randy,
It was a pleasure to meet you.
As long for the responsible harvest, there is nothing bad to get the biggest fish when we spearfish.
That's the good side of spearfishing, we can choose the fish we spear..It is much worst to get 10 small ones then one but a large size .From other side spearfishing is not that popular compare to line and hook, so the impact is so minimal there is no point to worry about..Look at the forum..A handful divers from Illinois and Wisconsin together

 

[foxfish]

Hi Randy, it sounds like you will make the perfect spear fisherman!
Though our sport you can be as selected as you wish when it come to catching your dinner!

 

[slimsteve]

Harvesting the largest fish is a bit like harvesting the older bigger deer in a herd. They are approaching the end of their life cycle when they get that large. I am not sure what average life span of various spieces are and how long it takes them to get to that size but it could be a worthwhile project to put some tables together so that spearos could make such decisions.

 

[Dannyk]

The MI DNR website states that the average life span of panfish is 5 to 6 years. Some do live longer. Most of the larger fish speared are probably in that age bracket. They reach maturity in 2 to 4 years.

 

[unirdna]

I've aged more panfish than I can count. Most definitely live longer than 6 years (8-12 is more like it), and we rarely spear any that are younger than 5. The big perch in Lake Michigan are 12+ years old. A 12 inch crappie is usually around 7-8. A 14 inch, 10-12. Ten inch bluegill are usually 8-10 years old.

Through my research, I see generations of panfish grow up. For example, a one-year old bluegill in Lake Monona is about 80mm and weighs 8 grams. Next year, that fish is 110mm and weighs 30grams. Next year 130mm, and weighs 60grams. Not until the fish is around 5-6 years old would most fisherman think of keeping it.

In short, there is good cause to be concerned about overharvesting. That is why it is so important to analyze the lake system with respect to each fish species. For example, the Madison lakes have shown time and again that fishing pressure has no impact on panfish abundance. Recruitment (reproduction) is so rampant for panfish species in these lakes that fishing pressure has little effect. What does have a huge impact on their numbers is temperature (hot summers are lethal) and naturally occuring bacterial outbreaks (usually in the spring).

That said, there are oligotrophic (clear, low nutrients) lakes in the north and Scott's neck of the woods that can be plucked clean by unscrupulous fishers. This especially holds true for bluegill and crappie during the spawning season, and perch in the winter. During these times, these fish congregate and are very susceptible to overharvesting. Futhermore, they need to have numbers high enough to protect their species from being wiped out. In other words, bluegills nest in a honeycomb for a reason - it helps each individual have a better chance of not getting ransacked by little predators. More eyes is a good strategy. On a tangent, this is why the passenger pigeon died off despite them lingering on for years after the huge harvest. These birds would all nest together in such massive numbers that predators simply got too full to eat them all. And since they nested in different locations each year, the predators could never count on migrating/congregating to an known nesting area. Once we knocked down their numbers below a survial theshold, they were doomed.

Back to the subject, I have a few honey-hole lakes I know of up north that I keep an eye on. I always pray that they will cool slowly or heat rapidly in the spring time, so that during Memorial Day weekend, the spawn will either be over or have not started.

So, in short, the best thing you can do for a lake is to ensure that you don't knock out a generation. If you see a bluegill nesting site, take a few, but not all. If there are 1000 fish, then go ahead and take your limit. If the lake is 50 acres, and all the bluegills nest on one sand flat, then leave them be until after the spawn.

Know your lake. That is the most responsible course of action you can take.

 

[Dannyk]

I've aged more panfish than I can count. Most definitely live longer than 6 years (8-12 is more like it), and we rarely spear any that are younger than 5. The big perch in Lake Michigan are 12+ years old. A 12 inch crappie is usually around 7-8. A 14 inch, 10-12. Ten inch bluegill are usually 8-10 years old................................................................Know your lake. That is the most responsible course of action you can take.

Thanks for all the info!

How do you tell the age of a fish?

 

[unirdna]

Thanks for all the info!

How do you tell the age of a fish?

Interpreting scales (most game/pan fish), spines (catfish, pike) and otoliths (fish that do not show good ring structure in scales or spines).

Perch from Lake Michigan -12 years old (not all rings are clearly visible under this magnification, but you get the idea).

 

[Kuiakua]

Kalin, it was nice to meet you and your daughter too....hope to do some diving with you in the future....

Ted, thanks for the super-informative post(s) (as well as your timely clarity reports). You are a great resource to this community.

I take it that since the Madison chain is not an oligotrophic lake (low nutrients?), the chances of putting a significant dent in populations is not a major concern (yay, I can get plenty of meals! ...if that was my goal...). So does that mean that by shooting every big fish you see that there is also little chance of creating a situation where the genetics for big fish could be wiped out? I'm thinking of the Twin Cities lakes where there are thousands of 4-5" bluegills and 6" crappies. Does that mean that these thousands of fish are just of younger year classes, or could it mean that a 6 year old fish there is just significantly smaller than a 6 year old fish here because of overharvesting of the big ones (depleting the "big fish" genetics)? Basically what I'm asking is: what causes big populations of stunted fish?

Scott told me that he primarily targets the males (darker crappies) during spawning, leaving the big females to spawn. This seems like a responsible thing to do. Any other tactics that people use to ensure healthy populations of bigger fish?

...sorry if this is a stupid question/discussion...

 

[kalin]

Randy I don't know for sure cause I know nothing about fish but what I think is that different lakes got different size fish not because genetics but the condition on the lake .....Fish is not like human.. They grow all the time if there is enough food..Millions small fish = no food = small fish..I was talking the other day with Scott about the same thing ..But thats me.I'll wait for Ted's opinion too.

 

[Whopperhead]

I also dont shoot any Crappie or Bluegill sitting on a "BED" or part of a Breeding Pair.

I know there is a lake up here by me "Silver Lake" that I have dove and swam the whole thing checking out the fish - In the Shallows and found out there "AINT JACK" in the deeper water. But mass majority of the pan fish were small and I wouldn't consider keeping any of them. It's not a over fished lake, just bad Genetics- I think. There isn't really much of an area for the public to fish there unless they are in a boat.

 

[fleshy]

Here it is plain and simple. I dont shoot any fish on beds. I dont ever shoot the biggest fish I see. If Im going to hit a lake hard, I only hit it once a year. (20 fish out of a lake once a year, although its been two years since I have done that) Remember that I come from central wisconsin however, and many of our lakes are small...so there is more of a concern about effecting the system. I would hope that everyone has respect for the animals and nature, and harvests accordingly.

 

[unirdna]

The factors that create a "stunted lake" are numerous and complex. Yes, removal of the large fish can have an effect, but sometimes it makes no difference at all. Foodweb dynamics, type/density of vegetative cover, lake depth, and reproductive strategies all have a major effect.

Here's something you may not have known. Bluegill females have one strategy for breeding - find a big, strong male with a nest and lay the eggs in that nest. But, the males have three strategies - 1. Be a big boy with a big nest 2. Pretend to be a female so you can wander around the big males and then sneak a spawning effort when a female lays her eggs. 3. Become sexually reproductive at 2-3 years old and try to sneak into the nest grounds and fertilize eggs when the big males aren't watching.

Now, insert the other factors I mentioned - foodweb dynamics, vegetative cover, etc. And you can see how different strategies would be advantageous. Heavy plant cover would favor the small ("seeker") males because they would not need to worry about predation. Wide open nesting areas would favor the big males, as well as the mimic females. But, the mimic females would only benefit if there are many big males, and not so many mimic females. If the lake is congested with mimics, then the big male has the advantage.

Now consider food dynamics in another scenario. How fast can you grow? Does it make sense to be a seeker, if food is abundant? The goal is to pass on your genes as much as possible in any given year. Are all the eggs going into one basket, or does it make more sense to spread out your effort for the long haul.

Bluegills are a very persistant fish. They will find a way to pass on their genes one way or another. It just so happens that WE prefer one of those methods over the other two.

All fish have their reproductive strategies, and most of them are pretty flexible. Crappies will build nests in the sand (Waubesa), or claim a big spawning rock (Mendota). They will spawn at smaller sizes if growth rates are slower, or if fishing pressure has removed all the large males (freeing up terriotory for smaller males).

"Stunted lakes" are not necessarily unhealthy lakes; they are simply homogenous and bad for fishing.

 

[Tass]

Great reading, I love it! Thanks Ted. Thanks for starting the thread Randy, good stuff. Looking forward to getting back to WI to get in the water.

 

[unirdna]

Here's some more reading for those that are REALLY interested.
I'll answer everyone's first question: A "cuckholder" male is one of the breeding "cheaters".

The short conclusion of this paper was that they could not find any conclusive evidence that high fishing pressure "stunts" lakes.

http://files.dnr.state.mn.us/publications/fisheries/investigational_reports/432.pdf

 

[land shark]

hey ted?

hows the carp experiment going on wingra?
you guys should be there spearing now before the vis goes to crap

 

[unirdna]

Exclosure experiment and radiotracking is complete. We now know their movement patterns, and can hammer them with netting efforts whenever we can come up with the grant money and manpower. I've tried to spear Wingra. Even on it's best day, it's not good enough.

 

[Tass]

I am very curious about where they go when they aren't in the shallows or spawning.

 

[unirdna]

I am very curious about where they go when they aren't in the shallows or spawning.

Open water - pelagic. Usually in schools. Sometimes hugging the bottom, munching fly larvae out of the sediments (after fall turnover). Sometimes suspended in open water, seemingly doing absolutely nothing.

The exact movements of panfish are much more complex in large (deep) lake systems. They take advantage of multiple food sources. Last year, for the first time ever, I hunted crappies in open water. It was quite a rush, and very very difficult to stay with the school as they chased after their dinner.

http://forums.deeperblue.com/wisconsin-freedivers-spearos/83534-pelagic-slabs.html