Evaluating Larry Hensley’s Lake
Allow me to introduce you to Larry and Jan Hensley, from Odessa, Texas. This 50-something couple has worked hard their entire lives. But, they also play hard. The Hensley’s have a ranch near the central Texas town of Brownwood.
In the midst of the hardscrabble ranch sits a beautiful 35 acre lake. The dam was built in the late 1990’s but the lake didn’t have enough water to stock fish for a year. At that time, long time fish farmer, Harrell Arms, from Proctor, Texas, stocked the forage fish. Coppernose bluegill, fathead minnows, golden shiners and redear sunfish fingerlings were stocked.
Two years later, the lake still wasn’t close to being full. That part of the world was in the throes of a severe drought. But, landowner and fish supplier made the decision to go ahead and stock bass. Pure strain Florida bass were stocked along with native strains.
By 2004, the Hensley’s were beginning to catch a few bass. Nothing special, as you would expect.
Things changed in 2005. It rained. The lake was close to full and finished filling in 2006. The Hensley’s were catching nice bass, up to four pounds. Then, a six pounder. Then more. Finally, a fish pushing seven pounds.
Yours truly and our cohorts have helped manage the lake for several years. Fertilizing, feeding program, more fertilizing, electrofishing, guiding and nurturing.
Hensley is not quite a worry wart, but he ain’t far from it. He loves his lake and its residents. He has my cell phone number in his speed dial. Let’s just say we talk often.
His bass are now five years old.
The lake looks great, but Hensley still isn’t catching the numbers of larger bass he would like. Spring of 2007 he rang my number. He caught a skinny bass, a 21 inch fish that weighed less than four pounds.
He was concerned.
His gut reaction was his fish just didn’t have enough food.
The lake is perfect for growing big bass. Lots of deep water coming off points with underwater structure. The natural contours of the land lend to sharp drops, rocky points and gnarly oak trees standing it deep water. There are shallow vegetated flats and rocky bottoms excellent for spawning habitat. It’s a lake with all the ingredients to grow huge bass in a balanced environment.
When I receive a phone call about a skinny bass, I rarely become concerned. It’s an individual fish, not usually a reflection of an entire population. Besides, I know this lake and one skinny fish is an anomaly. But, when he called again in September with the same concerns, I had him ship the fish. I was genuinely curious, especially since the bass are only five years old.
We featured that skinny bass in Pond Boss magazine. Its belly was full of plastic baits. Its lower intestine was blocked and that fish couldn’t digest enough food to maintain its mass.
We made the decision to analyze the fishery.
Two years ago, we recommended the Hensley’s begin to harvest young bass…those in the 10-13” size class.
They have taken a few.
This survey would tell us if they have harvested enough.
We launched the electrofishing boat late October and quickly began collecting fish. With Larry and Jan on the bow handling the dip nets, the live well filled fast.
During the next two hours, I drove the boat around the entire periphery of the lake putting 240 volts with about 7-8 amps directly in the water. As we passed near any fish, they were efficiently and safely stunned and collected.
Below is a table of what we found.
Species <1” 1-3” 3-5” 5-7” 7-9” 9-12” >12”
Largemouth bass 55
Coppernose bluegill 100’s 0 11 12 6
Redear sunfish 4
Bass were evenly distributed around the lake, mostly suspended 4 to 6 feet deep in water no deeper than 8 feet, near structure such as the canopies of standing timber or at the edges of submerged aquatic weed beds. Month old baby bluegill were found clustered near shore in dense vegetation. We saw no intermediate size bluegill, only recently spawned fish. That’s a strong signal. Very large, fat adult bluegill were captured near the feeders with a few random fish tucked tightly into brushy cover. That’s another strong sign.
What’s the sign?
A length/weight graph paints a vivid picture. It shows too many intermediate size bass clustered in the 12-15 inch size class. Plus, their average weights are definitely lower than “average.” Couple that with the data collected from the bluegill and we are seeing a classic case of overcrowded bass.
Here are the dead giveaways. Bass clustered mostly in one size class, very large bluegill with no intermediate size bluegill. Young of the year bluegill hiding for their lives in dense structure in shallow water.
For comparison, a “balanced” fishery has different sizes of each species of fish. Their frequency, when graphed, forms a wide “bell” curve.
How did this lake become this way?
By doing what good lakes do. It has raised lots of fish, starting with forage fish. Once the forage fish prospered, so did the bass. Stocked bass grew very well. Then, in their second year, they began to reproduce. The bountiful amounts of forage fish became adequate. Then, as the bass grow, they eat. More bass are hatched, feed heavily and forage fish numbers diminish. Picture this in your mind’s eye. Raise your left hand over your head. That symbolizes forage fish in the second year. Now, raise your right hand even with your head. That’s newly stocked bass in a new lake. Next, slowly raise your right hand and keep your left hand in the same place. That’s the second year of your bass lake, and your bass (right hand) are growing like crazy. Now, in the third year, your originally stocked bass are reproducing. Drop your left hand as your right hand rises. When both hands are even, you are balanced. Everything is working in harmony. There’s enough forage fish to feed your football-shaped bass. But, alas, it can’t stay that way. At some point during or just after the third year, your left hand drops below the right hand, symbolizing your bass at the point they are overeating the food chain. That’s the point where harvest of bass becomes a key ingredient in your management recipe.
Larry and Jan’s lake is just past that point. Where harvesting intermediate size bass was recommended, now it’s a requirement. If they don’t harvest at least 20 bass in the 12-15 inch size class, they can expect their bass lake to never reach its potential. Since one of their main goals is to catch some huge bass, harvest of these intermediate bass becomes a crucial move in their strategy.
Let’s turn the tables a bit. Let’s make this your lake. Let’s assume you are willing to harvest at least 500 bass, up to 750 fish during 2008. How do you know when you have taken enough bass?
Keep records. Weigh and measure your fish and track them over the entire year. Compare records in monthly, or quarterly, sections. When you harvest enough fish, the remaining fish will bulk up and begin to grow again.
So, there you have it. Common sense fisheries management. The recommendations for the Hensley’s lake? Harvest all the intermediate bass they can catch, at least 600, hopefully more. Fishing derbies, bring out the boy scouts, church groups…whatever they need to do. Increase the feeding program by adding two feeders to the existing three and step up the feeding frequency to three times daily. Fertilize the lake as soon as the water temperature reaches 60 degrees next spring. Stock threadfin shad in May, after the lake has a nice plankton bloom and at least 300 bass have been harvested. Consider stocking tilapia as additional forage fish. They did that in 2007 and algae disappeared. And, pay attention to young fish of all species. Use your observational skills to make sure you see baby fish all year long. When the bass begin to grow again, keep notes.
Tracking the lake’s progress ensures long term success.
What about big bass?
Follow these recommendations and big bass happen.
Bob Lusk is the nation’s leading private fisheries consultant. He is also editor of Pond Boss magazine, the world’s leading resource for pond and fisheries management information. Check out more of his work at www.pondboss.com or contact Bob Lusk, the “Pond Boss” himself, at 903-564-6144. His books, Basic Pond Management, Raising Trophy Bass and Perfect Pond, Want One, may be purchased by calling 800-687-6075 or ordering online at www.pondboss.com.