OBSERVATIONS by Al Kohutek
After 2 reschedules due to bad weather, the survey finally got under way. Brad Metzler and Mike Deiter of Pond King showed up at the boat ramp 10:15 AM and we were in the water by 10:30 AM. The survey ended at about 3:00 PM. Al Kohutek, Jon Griffin, Tom Root, Paul Poole, and Brandon Wooddell were present during the survey. Brad used a small John boat with a portable generator and a Coffelt shocking box. These boxes are used by the Texas Parks and Wildlife and are reportedly the safest available. Brad did 30 minute shock intervals starting at the boat ramp and working down the Rusdell channel, stopping midway in the channel to weigh and measure the bass and forage fish. He continued on down the channel and along Mike Walter's peninsula to almost the tip. Here Brad and Mike again measured and weighed the bass and the forage fish. There were a total of 6 check points. He shocked most of the shore line around the lake. The only areas missed were the very tip of the Food Lion cove, Poo Poo lagoon, the Fish bowl, and the north side of the Rusdell Island. Of the bass surveyed, 17 bass were over 3 lbs. and one was over 8 lbs. Brad had a way of examining the stomach contents of the bass with out causing any injury to them. One bass ate a catfish, some had bluegill, yellow bass, and craw fish in their stomach. Only 2 crappie were shocked. Brad said this was due to crappie being suspended in the deeper water. He also said he saw no signs of bass spawning and said the spawn should start soon. The weather was cloudy with light to gusty winds early in the morning and calming later that day. The water was murky due to the recent rains. The high air temperature was about 66 degrees and we got sprinkled on at about 1:00 pm. Fifty-seven carp, three gar, and five drum were taken out of the lake. Heath Wagner's old boat was pulled behind Jon's and it served as the carp transporter. Debby Kohutek made some great sandwiches for the entire crew.
I was very impressed by Pond Kings professionalism . All bass and forage fish were released unharmed and in excellent condition after the measurements were taken. You can visit Pond King's web sight at www.pondking.com The following information was taken from Pond King's survey report:
Bluegill Sunfish – The bluegill population consisted of both native and coppernose strains. We sampled a slightly higher number of natives, but neither was overabundant. The average size was approximately 5 – 6 inches. Bluegill that were smaller or larger than this were found in very low numbers. Evidence of survival of last year’s spawn was sparse. This indicates that there are too few spawning adults to keep up with the number of predator fish feeding on young of the year. The lack of 6 inch plus bluegill is another indicator of poor year to year recruitment of new spawning adults. Basically the bluegill are surviving but not thriving.
Redear Sunfish – Densities of redear were not high enough to consider them a functional part of the food chain. The survival rate of fingerlings stocked in an environment with an abundance of small bass is usually fairly low.
Gizzard Shad – The average gizzard shad measured 9 –10 inches in length. It takes an 18.5 inch or larger black bass to swallow a shad this size. These shad are not as prolific as threadfins, but they do produce a food source for the big bass. The trick is to have enough big bass to keep the numbers of large shad under control.
Threadfin Shad – We found about ten groups of threadfins that were from a late spawn of last year. These fish are predominately responsible for the survival of the bluegill and the condition of the largemouth bass. Maintaining high fertility levels and visibility at a maximum of 24 inches will greatly increase their production rates.
We also sampled smaller numbers of longear sunfish, silversides, warmouth, and juvenile yellow bass that contribute to the food chain.
To understand the condition of the bass population as it interacts with the present food chain, we are going to split it into three sections.
Small Bass (8 – 11”) – Average relative weights for these fish ranged from 72% to 89%. They are in the poorest condition of the three sections. Bass in this size range can only swallow bluegill that are less than 3.75 inches in length. The frequency of this forage is very low. Two options to improve the situation include removing small bass or increasing juvenile bluegill concentrations. The first option is undesirable because these bass produce a good food source for the large bass. The best way to increase juvenile bluegill concentrations is to stock big bluegill. Survival rates of fingerlings less than 4 inches would be less than 5%. A 0.5 lb female will produce 15,000 to 25,000 eggs. Even with high mortality of eggs and fry, you can still produce a good influx of juvenile bluegill. Higher densities of juvenile bluegill produce more spawning adults next year. Increasing threadfin production with feeding and fertilization will also help feed these smaller bass. Growing good densities of healthy small bass is important to increasing numbers of trophy lunkers.
Medium Bass (12 – 15”) - Average relative weights for these fish ranged from 88% to 93%. Bass in this range can only swallow bluegill that are less than 5 inches in length. Again the frequency of this forage is low. The majority of their condition is linked to the threadfin shad and other smaller bass.
Large Bass (16”+) – Average relative weights for these fish ranged from 95% to 124%. Bass in this range have the widest selection of forage available. They can consume the majority of the bluegill, threadfin shad, gizzard shad, and other bass less than 12 inches in length.
The following data shows bass over 7 inches in length, what the length of each fish is, the weight, what a bass of this size should weigh, and the relative percent. The under 8 inch fish were counted but not weighed.
|.||LENGTH||WEIGHT||SIZE CLASS||NORMAL||% RELATIVE|
This data places the 155 bass in an inch class giving the average relative weight. Our 9 inch bass are the most out of sync, weighing in at only 72% of the average.
|INCH CLASS||TOTAL NUMBER OF BASS IN THIS RANGE||AVERAGE RELATIVE WEIGHT|
The main goal for Lake Vilbig is to increase the frequency of largemouth bass that are 17 inches plus. The three keys to accomplishing this goal are maintaining a harvest program for the bass, maximizing threadfin production, and establishing the bluegill population.
1) Harvest about 1500 to 2000 bass in the 11” – 15” slot this next year. Keeping harvest records with length and number kept will be very important. You might want to have special tournaments harvesting the slot. Harvesting aggressively at the beginning of the year leaves that much more forage for the rest of the bass during the growing season. We occasionally have a market for bass of this size. They trade out at the rate of about $3 per pound.
2) Depending on visibility, fertilizing at 1 – 4 gallons per surface acre will increase lake production by 300 – 400%. The immediate benefactors of such a program are the threadfin shad. They are filter feeders and weight gain is directly linked to lake fertility. Increasing their numbers will take feeding pressure off of the bluegill and improve the relative weights of the smaller bass.
3) Stock adult coppernose bluegill (6”+). Seventy-eight percent of the bass that were sampled cannot eat a bluegill greater than 5.5 inches in length. The other 22% of bass have an abundance of food sources available. Survival rates of these bluegill would be near 90% and they will begin spawning immediately. Cost of jumbo coppernose when available is $.65 each. Feeding a floating fish food is also a great way to increase growth rates and overall production.
click here for pictures
10 pounds of forage to gain 1 pound on a bass.
lake, shad are a big part of the bass diet. Right now we have an excellent shad population but shad
populations cycle. Some years are
good and some are bad. If we have a
bad shad year without the needed bluegills to fall back on, then our bass will
time to build up the bluegill population is when there are large populations of
shad that the bass can feed on. This
gives the bluegill a better chance to take hold.
should be the main forage food of the bass.
They do not have cycles like shad and once established in good numbers
then they can be maintained without stocking.
culling our fish we can be selective. Bass
with high modeling (lots of the black marks, dark in color, and football shaped)
can be released in the slot. These
are most likely the Florida bass stocked over the years and we want to keep them
in gene pool. The bass that
are plain, with little marking, light in color, and that are in the slots should
be culled. These bass can be traded
for bluegill if not eaten.
important to keep counts and measurements on our cull bass.
bluegill stocking is 400 per acre. Stock
what you can.