Lake Report 2010

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French Village

2010 Electrofishing Report


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On May 24th , 2010 a fish population analysiswas conducted using standard electrofishingprocedures.

Data collected during this study was analyzedto describe the current conditions of the fishery.Based on the data collected, managementrecommendations have been made to improvethe fishery in order to reach your goals.


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Hardness and alkalinity were determined byusing a portable Hatch digital titrator. Weused a secchi disk to determine visibility anda portable pH meter to determine pH.


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Electrofishing is the most scientificallyadvanced method of analyzing fishpopulations in freshwater lakes and ponds inthe southeastern United States. Electrofishingprovides a fisheries biologist with arepresentative sample of all fish in the lake.


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An electrofishing boat was used that transmits an electricalcurrent from a generator through a control box to a set ofelectrodes that are hanging at the front of the boat andinto the lake.

An electrical field is formed around the area of theelectrodes. The field reaches up to 10 feet in front of theboat and to a depth of approximately 6 feet. This allows usto sample all habitat types found within the lake.

Fish within this field are stunned and float to the water

surface.

No harm is done to the fish and the fish will recovercompletely within 5 minutes.


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During the survey, the relative weight (Wr) wascalculated for all largemouth bass collected.

Wr is a coefficient used to compare thestandard weight of a bass at a given length tothe actual weight of the collected bass at thesame length. It is the ratio of the actual fishweight to the standard fish weight. A Wr of over80% is desired in a balanced fishery and above100% for a quality bass fishery.


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Wr = ______(Actual Weight of Captured Fish) * 100______

Standard Weight of Fish at Same Length (From Table)

For Example: If we caught a 11 bass that weighed 0.6 lbs. The standard

weight of a 11 bass in the table (following slide) is 0.8 lbs.Wr = (0.6) * 100

0.8

Wr = 75%

Valuesover 90% indicate a healthy bass population and

adequate forage base. Relative weights below this levelindicate limited ideal food sources for bass. Values below75% indicate a skinny bass.


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Length(inches)

Weight(pounds)

10.5 0.6

11 0.7

11.5 0.8

12 0.9

12.5 1.0

13 1.1

13.5 1.3

14 1.5

14.5 1.6

15 1.8

15.5 2.0

16 2.2

16.5 2.5

17 2.7

17.5 3.0

Length(inches)

Weight(pounds)

18 3.2

18.5 3.5

19 3.9

19.5 4.2

20 4.5

20.5 4.9

21 5.3

21.5 5.7

22 6.2

22.5 6.6

23 7.1

23.5 7.6

24 8.1

24.5 8.7

25 9.3


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Your goals are to produce a quality bassfishery with plenty of 3-5 lb bass withincreased chance at a trophy.

In order to achieve these goals you want tohave a diverse and balanced relationshipbetween the predator (bass) and the prey (i.e.

bluegill) populations.


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Parameters Results Desired Range

Environmental Temperature(F)

75 -

Water Temperature (F) 84 -

pH 8.3 6.5-9.0

Visibility (inches) 30 18-24

Hardness (mg/L as CaCO3) 11 >20

Alkalinity (mg/L as CaCO3) 15 >20


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Normal water quality and normal pH.

Alkalinity and hardness were low, which is an

indicator that the water has a limited abilityto buffer sudden pH changes. High alkalinitycreates a healthy environment for the fish andaids in success of fertilization program.


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The lake is approximately 17 acres in size.

The lake has a good amount of dense structure to provideprotective habitat for small fish. Also, the lake has somelarge structure to provide fishing hotspots and orientationpoints for larger fish (i.e. Bass).

The only aquatic weed found at the time of our survey was aslight amount of water primrose.


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Species Size Class(in.)

Quantity

Bluegill 9 13

Shellcracker 9 0

Largemouth Bass 18 3

Species Size Class(in.)

Quantity


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Known as bream to many, bluegill are the backbone of forage productionfor largemouth bass ponds. Bluegill are very prolific, reproducing multipletimes a season (3-5 times/year). This provides largemouth bass with a largequantity of food while still allowing themselves to sustain a healthy thrivingpopulation. They spawn in large colonies of nests in 3 to 6 feet in depthover sandy and gravel substrates close to the shore. Spawning occurs when

water temperatures reach 67-70F. Bluegill readily eat floating fish foodand have great growth rates from supplemental feeding. They also provideexcellent fishing opportunities for kids and novice fishermen. There are twosubspecies, native (also called Mississippi) and coppernose. Thecoppernose are better suited for warm climates and are more aggressivewhen feeding on supplemental fish food compared to the Mississippibluegill.


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Also known as bream, shellcraker occupy a different ecological niche thanbluegill, improving the utilization of the ponds natural productivity.Shellcracker eat snails along with other invertebrates present in the pondand can help to reduce the incidence of some fish parasites (i.e., grubs,flatworms) that use a snail as a intermediate host. Similar to other breamspecies, shellcracker are a favorite prey fish for bass. They can grow larger

than bluegill, but they are not as prolific, since they reproduce only onceper year. Redear sunfish can be distinguished from bluegill by the presenceof a red or orange ear tab.


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0

5

10

1520

25

30

35

40

45

3-5 5-7 7-9 >9

Class size

%

BluegillShellcracker

Balanced


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The bluegill population consisted primarily of larger fish (>7) and was limitedfor small bluegill (


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Largemouth bass are the preferred game fish in the U.S. providing excitingfishing for anglers. They will eat just about anything that they can fit intotheir mouths making largemouth bass the top end predator in most ponds.Largemouth bass begin to spawn when the water temperature reaches 63-68F, normally once a year in the early spring before bluegill begin tospawn. There are two known subspecies, Florida and Northern. Florida bass

are known to grow quite large but research has shown them to be lessaggressive when adults, making them harder to catch. Northern bass aremore aggressive but do not have the top end potential of Florida bass.

There is also the F1, which is a pure cross between the two having the bestcharacteristics of both subspecies (aggressive and grows big in size). Youcan also have Fx bass that are a mix of genetics of both subspecies.


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0

5

10

15

20

25

30

35

40

8-10 10-12 12-14 14-16 16-18 >18

Class size

%

ActualBalanced

Quality


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The majority of the bass population consisted of 8-12 bass.This explains the limited numbers of smaller bluegill becausethe majority of the bass population are consuming the 3-5bluegill. The average size of the bass sampled was 15, 2.4lbs., and the average relative weight was 80%. The relative

weight average indicates that the bass are skinny.

Three bass over 20 were sampled from the lake. All three ofthese bass were healthier than the smaller bass we sampled.Basically, these big bass are ahead of the curve and at 20 or

more in size, these bass can consume smaller bass. Since thereis a high abundance of smaller bass, these larger bass have agood forage supply which is why they are healthier. A 20 basscan consume a smaller bass up to 11.


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Continue with the fertilization program to maintain thevisibility between 18-24.


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Feeding the bluegill floating fishfood creates healthier fish thatreproduce at higher rates and growfaster. By using feeding program,you are supplementing the foodchain in the lake.

With feeders, the feed is providedon a continuous and regular basis.

Bluegill do not travel far to feedwhich is why it is important to havemultiple feeders set up on largerbodies of water.


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To enhance spawning habitat and improve spawning success of the bluegill and redear sunfish, Irecommend installing spawning tables.

The spawning tables are easily made using some cinder blocks and pea gravel or similar rock -1 inch in size. Starting from the shoreline, place the cinder blocks back to back perpendicular tothe shoreline out into the lake until the water reaches three to four feet deep. Next, place thecinder blocks parallel to the shoreline and continue parallel with the shore for another 10 feet orso. You can then close off the spawning table by placing more blocks back to the shoreline. Thecinder blocks serve to protect your investment in gravel keeping it from sliding down the slope.

You also find it useful to stake plastic or landscape fabric to keep gravel sinking in the muck.Finally, fill the area inside of the blocks with pea gravel. We like to have a depth of four inches ofpea gravel throughout the table. They do not have to be an exact size, but make sure they arelarge enough, typically five feet out into the lake and 15 feet long, to provide an area for severalnests.

These spawning tables help improve the bluegill population by first providing a more preferredarea for the fish to spawn, increasing success. The gravel is proven to increase the success of theeggs and fry. They also improve the growth rates of the bluegill because the bluegill do not have

to spend a significant amount of energy making a nest. Bluegill, along with redear sunfish andlargemouth bass, fan out a nest until they reach a hard/gravel bottom. When bluegill fan out mudto reach a hard bottom they are wasting energy several times per year. By providing the bluegillwith a hard surface that they can easily fan out for a nest, you have healthier fish that has moreenergy reserves for spawning efforts and nest guarding.


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We have sold these attractors for years. They do a great job of attracting and holdingfish in a given area. You need to put a minimum of three in a location to best satisfya basses ambush needs. They are plastic so they will last a lifetime. The biggestadvantage is the lack of lure hang-ups. It is practically impossible to hang a lure.The attractors come in 4 and 5.5 feet heights . The new Saturn series is better forthose installing close to shore and due to shape, it better protects the smaller fish.This allows smaller fish to gain in size prior to bass eating them leading to less energy

loss and better bass growth.


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A bass has to eat 10 lbs of fish in order to gain one pound inweight. Small one inch bluegill generally weigh 5 lbs per 1,000 fishthus the bass would have to eat 2,000 bluegill to gain one pound.Adding protective cover will allow the young bluegill to grow for anadditional month or more. In just one month, bluegill can quicklygrow to 20 lbs per 1,000 fish so now a bass only has to eat 500bluegill to gain a pound. This means much less energy is expandedallowing energy for growth. This is a simplified example butindicates how protecting the small bluegill promotes and isessential for good bass growth.

The attractors when placed in proper locations provide areas forfish hangouts/ambush points which also allows less loss of energyand improved weight gain.


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To help provide more forage for the bass we recommend stocking coppernosebluegill. The bluegill population was low due to years of heavy bass predation.Coppernose bluegill will feed aggressively on an supplemental feed resulting ingreat growth rates. Coppernose bluegill are more aggressive than the nativebluegill making them easier to catch. We recommend stocking 4-5coppernose bluegill. These fish are sexually mature and will reproduce activelyduring the warm season reducing the pressure of bass over the population

currently present in the lake. Keep in mind you can never have too manybluegill if wanting better bass growth so you may consider stocking even moreto speed up the improvements.


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Limit the harvest of forage fish such as bluegill and shellcracker. Itdoesn't hurt to take out bluegill here and there but the bluegill arethe backbone forage species for largemouth bass. So the morebluegill you harvest the more food you are taking away from thelargemouth bass.

To get the bass population back in balance, I recommendharvesting 425 pounds (25 lbs./acre) of bass measuring 12 or lesswithin a years time.


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As you see from these pictures, the bass on the left in Figure 1 needs tothrown back in the lake and the bass on the right needs to be harvested.In Figure 2 the bass on top needs to released and the bass on the

bottom needs to be harvested. You can see how the bass that needs toharvested is consistently skinny from the dorsal fin all the way down toits tail. You can see how the bass that needs to released is real thick, hasshoulders, and then gets skinny at its tail. These are the kind of cluesyou can look at to determine if a bass needs to harvested or not.

Figure 1 Figure 2


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Recommendation Quantity Price

Texas Hunter Feeders Any interestedhomeowner

$775 installed

Harvest Bass 12 and under 25 lbs/acre

Bluegill Stocking 200/acre $750/thousand


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Water Quality ParametersSupplemental Feeding Program


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pH: The pH measures the concentration of the hydrogen ions present in the water, and

is usually thought of as the measurement of acidic or alkaline conditions. A pH of 7is neutral with lower values being acidic and higher values being alkaline. Mostorganisms in a lake prosper when the pH is maintained between 6.5 and 9. The pHcycles daily due to a complex interaction of alkalinity, hardness, carbon dioxide,and photosynthesis and respiration. The lake is more acidic in the mornings, and

will also vary according to depth. When pH levels are out of the desired range forlong periods, detrimental affects may occur.

Hardness: Hardness is a measure of the quantity of divalent ions in water. Generally in

Georgia, calcium and magnesium carbonate account for the majority of thehardness. Hardness levels affect the toxicity of some algaecides, limit

phytoplankton formation, and play a role in fish growth. Levels below 20 mg/lshould be increased with the addition of 4-6 tons per acre of agricultural lime.


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Alkalinity: Alkalinity is defined as the quantity of base present in water. The most common bases

include carbonates, bicarbonates, hydroxides, and phosphates. Total alkalinity is closelyrelated to hardness with both being reported as mg/l CaCO3. Alkalinity basically determinesthe buffering capacity of a lake. A good buffering capacity will absorb introductions of acidsand bases with little change in pH levels. By maintaining the desired pH levels nutrients aremore available to phytoplankton resulting in a lake that has an increased carrying capacity.

Visibility: Visibility is measured with the use of a secchi disc. The white/black disc 20 cm in diameter is

lowered vertically through the water until it can no longer be seen. Suspended particlesreduce this visibility level. Therefore, in the absence of turbidity from silt or mud the secchidisc serves as a international standard to indicate phytoplankton. We recommend keeping aphytoplankton bloom with a visibility between 18-24 inches via fertilization.


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One of the easiest and most efficient methods for improving your pondfisheries and bass growth is by feeding your bluegill population. Feeding thebluegill a supplemental fish food diet creates healthier fish that reproduceat higher rates, therefore increasing the population. More importantly,feeding bluegill increases their weight, which consequently increases theweight of the bass. Feeding can occur year around in some areas but

generally begins in March and continue through November in much of thesoutheast. For bluegill use a moderate protein level such as 36%. This is abig advantage versus cheaper 32% protein food.

Bluegill will not travel far to consume food. In order to maximize bluegillgrowth and production, it may be necessary to feed in more than onesection or to setup multiple feeders in ponds greater than 1/2 acre. Allponds are shaped differently, but typically a minimum of 1 feeder per acre

may be necessary to feed all bluegill in smaller ponds. For ponds greaterthan 10 acres 1 feeder/2 acres are sufficient.


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Report Prepared By:

Render Ward

Lake Report 2010

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Transcript of Lake Report 2010