Unnatural Selection causing fish to get smaller

[bfishn]

23 hours ago, snagged in outlet 3 said:

Full of yourself aren't ya?

Full of something, for sure.

[MoCarp]

46 minutes ago, tjm said:

See, they kept turning the little ones loose and ate (or mounted) all the big gene pool. It's easy to see why all we got now is fiddlers, that is all our predecessors let go. Blame Mark Twain and his buddies for all the small fish left nowadays. Never read about the guy guy that caught 100# plus fish and turned it loose to reproduce, nope they mounted all them genetics.

 

Its not only the genetics issue Catch and release works.... many fish, even on Taney have been recaptures...

"Catch and release is an investment in future fishing success"- Quote from Bill Dance

29 minutes ago, MOPanfisher said:

Whew, I thought it was just that fish didn't get to live as long due to more fishermen etc.  Good to know it only the genetics getting watered down.

Over Time it happens, its something of concern as researchers are looking over old records and accounts photos etc..in some cases fishing is far better... but in search of better fishing genetics are a key issue today and the ability of a fish to reach a large size quickly...stream smallmouth are notoriously slow growers...everyone knew a smallish man in school...never will he reach 6 foot and was in 11th grade before his voice changed....we have inherited the smallmouth equivalent..the "right" genes are out there just need to have a program to locate and propagate those desired traits

20 minutes ago, bfishn said:

Full of something, for sure.

Yes I sure am...., a lifetime of knowledge of the outdoors and the science that drives the dynamics.....if I make you uncomfortable just hit the ignore button..if not think about what is being said with an open mind....would you rather have a day fishing an Ozark stream catching 2 pound smallies with a sprinkle of 5 pounders? instead of 10" bronze backs and a lone 2 pounder being a good day?

[Daryk Campbell Sr]

Without being long winded,  I believe cnr has made a difference in the size of fish.   There are more fish continually fighting for the same things.  We all learned that many fish in one pond will keep the fish small no matter the genetic makeup.  Fewer fish in the same pond will get larger.  100 years ago, it was common to remove stringers of large fish, the small fish had a lot of opportunity to become larger.   Now, we shame any one for removing fish.  Sure, many still do, but not on the caliber that used to be. (When the fish were commonly larger) 

[fishinwrench]

I notice a change in fish behavior here on LO.  Fewer fish prowling the shoreline cover, and more fish moving about in open water and suspending.   LM Bass are acting more and more like Stripers it seems.  

I have a feeling that it is because of all the constant relocating of every keeper that gets caught, but I really don't know.  I was always able to find and catch shallow cover oriented bass but as time goes on it is becoming harder and harder to find fish living in that environment here.   Even during the spawn it's like they are in a hurry to get the hell out of the shallows and back out to the open water.   Very unlargemouthlike IMO.

[MoCarp]

Fish and fishing have changed a lot in my lifetime...I started fishing in the late 60's

... then through my early adulthood in the late 70's...

things have changed, way more people  here than in my youth

the turn of the century was as far removed from then as we are today from the 70's.......

[MOPanfisher]

I suspect several factors are at play, including an increased rate of harvest, habitat changes, behavior changes, possibly some genetics, more anglers and of course a shortage of baby carp to eat. 

[Al Agnew]

Okay, I thought we examined this genetics thing a little earlier, but let's look at it closely.

First of all, the genetics of a fish don't change as they get older (and presumably bigger).  That 4 year old 12 inch smallmouth from Current River that was taken out and eaten COULD have had the genetics to grow bigger than the average.  It didn't have to reach 20 inches for those genes to kick in.  So, just taking the biggest fish and keeping them doesn't necessarily mean you have removed those genetics from the population, because that fish had already spawned multiple times and passed on those genetics.  As long as it's legal to keep fish over 12 inches, the ones with good genetics and the ones with less than good genetics are equally likely to pass on their genes.  Or not pass them on.  

This is a little different from a critter like a whitetail.  We know that some whitetails have inferior genetics and their antlers will never reach trophy proportions.  If most deer hunters are looking for those with bigger antlers, they are going to be cropping off the ones with the best genetics when they reach 3 or 4 years in age, while the ones with little sickly looking antlers will NEVER be cropped, and will keep producing inferior deer for a longer number of years.  But when it comes to fish, it doesn't quite work the same way, because there is nothing to choose from in deciding which fish to harvest, until the ones with the good genetics have already reached a size that's bigger than the rest of the population, at which point they've had plenty of time to pass on their genetics.

So in my opinion, the only way to move the overall population to one that has a greater percentage of big fish, is to simply protect the big fish.  Because you don't know which ones will reach trophy size until they actually reach trophy size.  You can manage to improve growth rates by encouraging harvest of smaller fish, so that the ones that are left have more food and thus presumably greater growth rates.  At the same time, you have to keep enough growing fish in the population to have a good number that are approaching trophy size.  Which is the rationale behind slot limits, except that slot limits still encourage harvest of SOME big fish.  So truly, if you want the maximum number of big fish in the population, you would theoretically encourage harvest up to a certain size, while completely protecting every fish above that size.  Whatever minimum size limit you have only manages for more fish to reach that particular size, if you then allow harvest of fish over that size.  A 15 inch minimum length on smallmouth is managing for more fish of 15 inches, not necessarily a lot more fish of 18 or 20 inches.  It's the one fish limit, coupled with the 15 inch limit, that does the real job of producing more "trophy" smallmouth.

However, there are possibilities, seems to me, that anglers ARE changing fish population genetics, and Wrench's example is perfect.  Bass that hunt the shoreline are more vulnerable to anglers than those that roam in open water, where they are harder to find.  Is hunting the shoreline versus roaming open water a genetic thing?  Are some bass genetically programmed to forage one way and not as much the other?  If so, then we ARE inadvertently selecting for open water roamers.  And maybe some fish are genetically programmed to be more susceptible to the actions of popular lures than others, and those bass have longer to pass along their genes, thus making fishing tougher for the average angler even though there are just as many bass in the water.  Or maybe some fish are just genetically more wary, with better senses, or with a preference for staying in very heavy cover where they can't usually be caught.  Who knows?

 

[fishinwrench]

My theory, which has no scientific foundation whatsoever, is that LM bass are basically home range critters that do best when they are living in a very familiar area.  When you start relocating them to unfamiliar areas over and over then I think eventually they change their habits.  

Everytime a fish gets familiar with a certain area...POOF somebody catches it and hauls it to a new area of the lake.

So now they've said "screw it", I'll just hang out here in the middle of the great abyss and chase shad schools with the Whites and Stripers.  Might as well because I'm always lost anyway.

I know it sounds humanistic (in thought) because of the way I try to get my point across but I really do think this is happening.   All last Summer when most everyone was struggling, and all this Summer when the majority of good bass fishermen just simply were not catching them the Crappie guys out trolling little pink cranks way out in the middle of nowhere were wading through the 3-5 pounders. I've been hearing them complain about it for several years now.     

Say what you want but THAT is not typical bass behavior.   This is a relatively new thing.

[MoCarp]

5 hours ago, MOPanfisher said:

I suspect several factors are at play, including an increased rate of harvest, habitat changes, behavior changes, possibly some genetics, more anglers and of course a shortage of baby carp to eat. 

pay particular attention to the section on prey species, 

http://www.in-fisherman.com/bass/factors-giant-bass/

[tjm]

Did anyone keep records of the prey species available to stream predators in the 19th or 20th centuries, when the fish reportedly grew so large? 

My mind tells me that there were lots more crawdads in the Elk River tributaries in the '50s than there are now, I believe there were lots more crawdads in the '80s than there are now. Where as a small boy I caught scads of crawdads and even my kids caught some, I don't recall seeing any in several years. I'm sure there are still some there, but so few that they aren't usually seen.