Shrimp Ranch Mngmt by Pepe Hernández

Shrimp Ranch Management

LightHouse Seafoods Group

A ppe ndix A H o w To G r o w Shr im p

Contents Chapter 1 - How to grow shrimp A - 3 A Brief Introduction Where to start

How much land is needed' ) What is the- bes t pond s iz e/s hape/depth? A 4 What type of land is bes t? A How do l construct the ponds ?

A -

Getting water out of the pond

4 5

Getting water into the pond

WAT ER EXC H AN G E For those with A A - ex is ting ponds 8Pond Preparation for seeding

PH OF POND BOTTOM(S):

Filling the pond with water

FILTERING THE SEAWATER

PERMITTING Preparing the s hr imp seed for deploy ment A -Aeration, when and how muc h A 1 Extensive produc tion aeration needs A 3 Intensive produc tion aeration needs

Seeding, Aeration and Feeding

9 1

Seeding, how many do y ou need?

Selecting the shrimp seed

Seeding y our pond(s)

1 -

3 4

1 1

AERAT O RS A A-1 1ÂŠ Copyright LightHouse Seafoods, ;he. 1995 A il Righis Reserved. 6

5 5

S hr im p R a nc h M a n a g e r m Hyper-intensive production aeration needs A - 1 7 Feeding

Sampling the shrimp

Extensive feeding requirements

Intensive feeding requirements

FEEDING:

Percent Body Weight (PBVV) method for feeding

A - 2 1

PBW AND BWG METHODS Body Weight Gain A 2 (BWG) method for feeding FCR AND YO UR PRO DUCT IO N 2 Harvesting A 2your4shrimp

- shrimp market The

2 5 The easiest market The "Liven market A The local "fresh, h e a d s 2 6 Your financial needs

A A

off (The F current H O F size F ) of" the shrimp m a r k e t How to harvest your shrimp A 2 6

A - 2 3

A A

2 2

8 9

Ap p e n d i x A H o w To Gr o w Sh ri mp

Appendix A H o w to grow shrimp A Brief Introduction Growing shrimp in ponds is not as diffi cult as some would lead you to believe. I t is, however, a financial risk and can be labor intensive. I n essence, you throw a bunch of baby shrimp (called ''post-larvae" or simply "PLs") into a salt-water pond, care for them by feeding them shrimp food (yes, there is a "Purina ShrimpC h o w " ) , exchange and aerate their water, wait (while maintaining the farm) and finally harvest the crop. 1Nhile the preceding explanation is a slight over-simplification of the task of growing shrimp, it is the basic method used by shrimp growers throughout the world. A s explained in the Introduction to this manual, the level of production, i.e., Extensive, Intensive and Hyper-Intensive, will dictate the amount of effort, energy and feed you will have to use to achieve a successful crop.

Wher e to start Before you do anything you must assure yourself that you have sufficient land for a pond or ponds that you are willing to dedicate to growing shrimp. This land will be flooded with salt water and will be of little use for any agricultural purposes for many years. This land must also be as dose as possible to a source of dean salt water. Shrimp prefer water that has at least ten (10) ppt salinity (the salt content of the water expressed as parts per thousand: open ocean salinity is 35 ppt). Local extension services can do the testing to determine this issue. Ideally, extension personnel may also be able to provide to you the historical average salinity for your source of salt water. The first instrument we suggest you buy is call a Refractometer, a fancy name for a device to measure the salinity of the water. These are really Specific Gravity units that have been calibrated to read salinity. I t requires no batteries, will last a lifetime and you will use it throughout your shrimp growing career. A-3

S hr im p R a nc h M a na ge r H o w m uc h la nd Is ne e deTd? N As a rule of thumb, you will need one and one-half acres of land for every acre of pond surface. W h a t Is the best pond s iz e /s ha pe /de pt h? The ideal pond size is between two (2) to two and onehalf (2 1/2) acres, an average of five (5) or more feet in depth and rectangular. This, however, is not always an achievable goal. I f necessary, sacrifice size for depth. Fo r example, a one half (1/ 2) or three-quarter (3/4) acre, six foot (6') deep pond is far superior to any sized pond that is shallow (less than four foot average depth). A two (2) acre pond is displayed below.

1 4 1 4 0 0 Fig. 1. Bas f k pond shape for a two (2) acre shrimp pond. Does riat show access dikes. e e t Depth is critical for a number of reasons. First, it greatly

reduces the opportunities for predators (all those lovely birds in the marsh that love shrimp) simply because they cannot stand in your pond and eat your crop. Secondly, the added depth provides an environment that more nearly mimics the shrimps natural habitat. Finally, deep ponds hold more water, thus providing a larger "buffer", or holding capacity, that will allow you to weather less than ideal growing conditions (your water pump blows upÂť. So, to recap, at the very least you will want deep ponds, near a source of dean salt water, of a size and shape that suits your land and/or production goals.

A-4

A p p en d i x A H o w To G r o w Sh rim p W h a t t yp e o f l a n d is b e s t ?

You will, of course, want land that will retain water. The ideal type of land has a good clay content. Mo st coastal areas in the South Eastern U.S. are primarily sand but many areas have a layer or layers of day or dense loam that are suitable for pond construction. Short of having the appropriate mix of clays the potential shrimp grower can line their pond(s) with s o plastic liners manufactured to withstand direct sunlight. This, while increasing the expense, is a viable c a l l ehowever, d substitute. " G e o m e m b r a n e s " Keep in mind, as well, that the bottom of your pond must be w h at least i six inches to a foot (6" to 1') above the average high-tide c h mark for your area. The pond(s) must be completely drained and allowed to dry in between harvests and a subsequent seedings. This drying period allows for sludge r removal and destroys any harmful diseases that may have e accumulated. See Pond Preparation later in this manual. j u sH o w d ot I c o n s t r u c t t h e p o n d s ? Pond construction is essentially a high ground diking procedure. Th e actual construction techniques are left to the potential shrimp grower. Keep in mind, though, that the top of the dikes must be built to accommodate your feeding method(s), i.e., wide enough to allow passage of a mechanical feeder, if used, or no wider than a walking path i f feeding by boat. In either case, keep the dike slopes to at least a 1:3 ratio to avoid unwanted erosion and dike slope "creep" down into the pond bottom.

,AN"tfr,

64 :••

•• •

;

Fig. 2. General shape and side slope of a typical shrimp pond. Note depth.

A- 5

S hr im p R a nc h Managerrm Also, remember that a smooth pond bottom is very desirable. Little hills and valleys on the pond bottom will encourage the feed (which is designed to fall to the bottom) to concentrate which will, in turn, encourage the shrimp to do the same: this is not good. The more evenly distributed the shrimp are the less likely they will become agitated, fight and even eat each other. Whatever method of pond construction is used, observe the minimum, acceptable pond depth and some workable means of getting water into and out of the pond (depending on your planned production method). Ge tting wa te r into the pond Getting water into the pond has a number of solutions. This can be accomplished by (in order of best to worst): 1_ an "in-flow" canal whose maximum water level would be level with the highest surface level in the pond and a simple weir for the control of the passage of water from the canal to the pond Transfer I n fl o w rAr Floe T o p C a n a l

Abbreviated pond side

Fig. 3 Canal in-flow yystem of water delivery.

a "piped in" system where the water flows through a series of PVC pipes from the water pump to each pond.

Abbreviated pond side

Fig 4_ Piped-in system of waterdelivery_

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A ppe ndix A H o w To G r o w Shr im p Generally speaking, hyper-intensive shrimp production, i.e., greater than 5,000 lbs per acre, requires at least a fifteen percent (15%) exchange of water in the pond per day (or one (I) complete exchange per week). A s a starting point consider a two (2) acre pond w i th an average depth of five feet (5 1 acres X 40,000 f t ). 2 ft of water (at 15% exchange) per day or 20,000 /Taexchange 3 cre X gallons h ' per hour or 333 gallons per minute. A one (1) acre 5 = pond i -d e would p t require half that amount, a four (4) acre pond twice that amount. These numbers may seem high, and they s h 3 are, to the average persons normal concepts of ,-p compared , water usage but remember we are talking hyper-intensive o 0 0 4 2 shrimp production, i.e., 6,000 to 11,000 pounds production ,n 0 per acre. B y reducing production to the levels listed below, d 0 0 0 you ,fw can t sharply reduce your water needs and, as in the case of extensive production, reduce the water exchange to zero i(0)! 3 0 l X 0 -l 0 For intensive shrimp production, i.e., -2,000 to 5,000 h 8 g pounds production per acre, use the seven percent (7%) o g a a water exchange. Fro m the example above, this exchange lrate would l orequire about 170 gallons of water per minute for d ln s acre pond. a two (2) /o 3 For extensive shrimp production, i.e., - 1,000 pounds n s.and less production per acre, you would be safe merely )2fi lling the pond and then leav ing it alone. Ex tens iv e s hr imp .m growing ordinarily does not require water exchange. This i T method of farming lends itself to the simplest water system lwherein you simply pump the pond full by whatever means h and forget it. Because this is the simplest it is also the safest il si(although there is still some risk, albeit slight compared to tothe more intensive methods). rn gGe tting wa te r out of the pond a a n Getting the water out of the pond is best handled by a sl "out-fall" weir system. Thi s will allow for easy control of the l pond depth and lends itself to pond-draining harvest metho a ods most generally used and preferred in the industry. tn s e A-7 so if w n ta t o e 4

Shr im p R a nc h Managerrm

Fig. 5 Out-fall graphic showing general design

Be sure to size the out-fall system to allow for a complete draining of the pond in a twelve to fifteen (12 to 15) hour period. Th a t is, for a two (2) acre pond five (5') foot deep, use an out-fall pipe of at least a three (3') foot diameter_ Thi s sizing is fixed, i.e., regardless of the production level chosen, stick to this out-fall sizing. WATER EXCHANGE: For intensive and hyperintensiye prod ucEon systems, the shrimp farmer has, essen!daily, only two (2) methods available to handle the emergency of the water going had in their pond (s): water ex ch ange and mechanical aeration. I t is vital that the ability to flush the pond(s) be available at all times! This cannot be emphasized enough. C u tti n g corners in this area of shrimp pond construction is illadvised and significantly increases the risk of crop failure_ For extensive production situations, of course, you should not need to exchange any water. REMEMBER that pPrrni ts are required for water discharge. See the note on P E R I= L N IG on page 24 for the central State contact for permitting. For thos e with e x is ting ponds If your ponds do not conform to the previously described parameters, do not despair. M o s t likely the ponds are not deep enough and although this is less than desirable it is not fatal. The vigilance issue becomes somewhat more critical, especially if you intend to increase the density of your crop. A-8

A p p en d ix A H o w To G ro w Sh rim p

By following the production schemes outlined in the remainder of this manual, you will still be able to realize increased crop volume. Attention to critical water quality, predation and maintenance issues will, however, be more time consuming and the inherent risks will be greater.

Pond Preparation for seeding Pond preparation prior to seeding is essentially a matter of adjusting the pH (or acidity or alkalinity) o f the soil in the pond bottom. Mo st coastal soils tend to be slightly acidic (a pH less than 7.0. A pH of 7.0 is considered "neutral" or like that of distilled water). Th i s is easily rectified by spreading lime over the pond bottom at the appropriate rate. The best method for determining the p H of your pond bottom is to take several (i.e., 10 per acre) samples of the bottom soil. Be sure to take samples (-1 to 2 cups worth) that go at least six inches (6") deep_ Arrange to deliver these samples to the Department of Health or your local extension service and ask them to test for the pH and to suggest a liming procedure and quantity. You will ordinarily receive a form that describes, by weight per acre, the exact limin g needs of y our pond. H OF PO ND T T

I %al

F ailur e to observe this p H balanc ing proc edure can have very negative effects on y our success in gr ow ing shrimp. T he s hr imp seed

(the PLs) are extremely sensitive to acidic (or alkaline, for that matter, hut to a fa r lesser degree) water conditions. Once you are satisfied that the pond bottom is ready (you've removed all of last season sludge piles [i f there was a last season], smoothed the bottom, limed, etc_) you are ready to fi ll the pond w it h water-

A- 9

S hr im p R a nc h Managerrm Filling the pond with wa t e r This one is easy. Fill the pond with water. Ordinarily, you would try to use an in-coming (neap) tide since this w i l l have the highest available salinity. I f the out-going (ebb) tide tends to have a low salinity it is best to wait for another neap tide to continue filling your pond. The basic idea is to have the initial pond water with as high a salinity as possible. There is two (2) things that are equally important that deal w i th the algal "bloom" and filtering the water going into the pond. It is generally necessary to "feed the pond" (fertilize) with some leftover shrimp feed or some commercial nutrients to encourage the initial growth of the algae. The algae, which will "bloom" (grow in density), provide two (2) important conditions for growing your shrimp. First, the algae add oxygen to the pond water (while consuming shrimp excretions), much the same way as a tree or any green plant adds oxygen to the air (even though the particular algae you may see in the pond is not green). Second, the algae, if properly dense, will act like a shade to the bottom of the pond, thus discouraging growth on the bottom which would interfere with the shrimp finding the feed you will be adding later in the growing cycle (intensive and hyper-intensive). FILTERING THE SEAWATER You must fi lter the incoming sea water. The shrimp PLs are very small and make excellent food for all mariner of sea creatures. At the least, fi lter the water going into the pond. You may, alternatively, filter the water coming out of your pumping system. Fi l tering eliminates these predators and, to a large extent, the larvae and eggs of these predators that would otherwise get into the pond(s). You should continue to filter the water for at least one to three (1 to 3) months. The duration of the filtering period will vary depending on the size of the shrimp as they grow. Co n n e d nexl page

A-10

A ppe ndix A H o w To G r o w Shr im p The recommended fi lter should have a mesh size no larger than five-hundred mi crons (500p.). These filters will need periodic cleaning. Once your shrimp are four to five grams (4 - 5 g) in size you may remove the filters.

Selecting the shr im p seed There are currently three (3) species of shrimp that are recommended for farming. They are: I. Whatever species occurs naturally in your area - for South Carolina it is the P. set iferus (white shrimp). The P. is an abbreviation of the Latin word Penneaus, which precedes all the species we will be discussing. This shrimp does OK in ponds but not as well as the species listed below, especially at higher densities (intensive and hyperintensive). Th e up-side of using th i s shrimp is that no importation permits are required, nor is there any need for out-fall screening. Th e downside is that they grow slowly. 2. Th e exotic P. van namei (the Pacific white shrimp, often referred to as the "Vanna White") w hic h is the mos t w idely used s hr imp for far ming in the Western Hemis phere ( ninety percent l90%1 of produc tion). T h e animals tolerate inc r edible

crowding, grow rapidly and are very hardy. Some sources of the PLs of this species have a disease known as a ll- N V * (its description is beyond the scope of this manual) which causes stunting, lower survival and lower harvest weights. In the U.S. there is a "disease-free" version of this shrimp that is referred to as "SPF" or "Specific Pathogen Free" (also sometimes call "high-health"). This is the preferred shrimp seed because there is no stunting, higher survival and much higher harvest weight. Unfortunately, they are not always available and often cost fi fty percent (50%) more than the non-SPF seed. Infecrious Hypodermal and Hetnatopoietic Necrosis Virus

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S hr im p R a nc h M a n a g e r m 3. Finally there is the P. Stylirotris species, often called the "Pacific Blue" or "stylies". This animal, rejected for farming ten years ago, has recently returned to favor because of its very fast growth. A t this time, however, it has not been widely farmed and still represents somewhat of a risk. Some farmers have mixed the P. van namei and the P. stylirotrus in the same pond to hedge their bets. These so-called "stylies" perform very well, producing a marketable product in as little as three (3) months but they have not been grown widely in recent years and still represent a certain risk. Th e disease M E N ) " used to cause severe mortality (death) and as such these shrimp should never be grown where the disease is known to be a problem.

Seeding, Aeration a n d Feeding S e e ding, h o w m a ny do y ou n e e d ? The density of the shrimp you seed into your pond and the final harvest weight is determined as follows: Harvest weight Goal (e 1 ,0 0 0 l b s per acre) Individual shrimp weight goal (e.g., 19 grams, or the high end of a 21-25 count/lb shrimp) 1,000 X 454 (grams per pound) = 454,000 grams 454,000 / 19 = 23,895 shrimp per acre Now, not all the shrimp seeded into a pond survive to harvest_ A s a rule of thumb, about seventy percent (70%) of the seed should survive to harvest (assuming a twenty-six (26) week growing period). A s a result, you must multiply the 23,895 SPA above by 1.429 (or 1 / 0.70 = 1.429) to compensate for the 30% loss: 23,895 X 1.429 = 34,136 or - 34,000 SPA The above for mula applies to any dens ity y ou choose,

e.g., for a 10,000 lb harvest goal and a 19 gram shrimp goal you would want to seed 340,000 SPA. Fo r a 500 lb goal you would seed at 17,000 SPA. A-1 2

A p p e n d i x A H o w To G r o w S h r i m p

Seeding your pond(s) RM TTIN Prior to actually adding shrimp seed to your pond(s) it is imperative you check with your local or State agencies concerning the importation o r possession o f "exotic" (n o t naturally occurring) species. There may also be some sort o f permit required as well as screening and/or netting placed at your outfall points to prevent the escape of the shrimp from your pond(s). These requirements vary from State to State (in South Carolina, contact the State Aquaculture Coordinator in Columbia for appropriate forms). Once you have satisfied all the various State requirements (see section o n Permitting), yo u are ready to actually seed yo u r pond(s). After checking for unusual shipping water conditions (see the following paragraph), preparing to add the shrimp seed to the pond is really a straight forward process which has only two (2) specific areas that are critical. Preparing t he s hr im p s e e d for de ploy m e nt Open each shrimp seed container one at a time and observe the baby shrimp (they are very small) to make sure they are all moving. A t the same time, smell the container to check for ammonia (baby pail odor). Ideally, there will be no ammonia odor but if there is, the following procedures should be accomplished as soon as possible. Th e ammonia smell indicates that the water the shrimp seed are in is going or has already "gone bad". The longer the shrimp remain in the container, the greater the chance the shrimp will be stressed or even killed by the poor water quality conditions_

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S hr im p R a nc h Manager).* First, upon receiving your shrimp seed, you must allow the seed to acclimate (get accustomed to their new home) by placing the closed container that the shrimp arrived in into t_he pond. This will give the water of the shrimp container to come to the same temperature as that of the pond. This avoids "shocking" the shrimp with a too-fast change in temperature. Th e time for this procedure varies, of course, with the temperature difference between the container and the pond. Usually, one-half (1/2) to one (1) hour is suffident. Check the container temperature occasionally. Then, once the temperatures are equal, slowly start adding pond water to the shrimp container, stirring and mixing constantly, to allow the shrimp to slowly acclimate to the salinity of the pond water_ Thi s can be accomplished in fairly short order, say ten (10) to fifteen (15) minutes_ Once you are satisfied that the acclimation procedure is complete, gery_ pour the contents of the shrimp container (with the shrimp) into the pond_ That's it. A e r a ti o n , w h e n a n d h o w m u c h Aeration is the process of adding oxygen to the water in the pond. The need for aeration is completely dependent on the method of shrimp farming you choose, i_e_, extensive, intensive or hyper-intensive: only intensive and hyperintensive production require aeration_ There are two (2) basic methods available to the shrimp farmer to determine the level of Dissolved Oxygen (DO) in your pond water: Chemical and electronic. D O is expressed as PPM in the U.S., or parts per million, a value that can range from zero ppm (0 DO) to 8-10 ppm_ The air you breath averages â&#x20AC;&#x201D;6 ppm. T h e shrimp need at least three (3) ppm DO. A n y DO level less than 3 ppm will stress the shrimp and eventually they will, quite literally, "drown" for lack of oxygen_ The chemical method involves a process called "titration" whereby performing a series of chemical reactions will reveal the DO level. A number of companies sell small kits A-1 4

A ppe ndix A H o w To G r o w Shr im p that include this process. Th i s method is inexpensive, reasonably accurate, but slow and inconvenient. The electronic method of DO detection generally involves a "DO probe" attached to a hand-held electronic readout device that will display the DO in the pond water. So long as calibration and maintenance procedures are followed, this is the preferred method of DO determination. I t is comparatively expensive, very accurate (making note of the previous sentence), quick and convenient. Both DO determining methods describe here are available from a variety of vendors easily found in any of the number of trade publications that are related to "aquacalture", or the farming of fresh and salt water animals. When to begin aeration is DO level dependent_ Ord i narily, you start to aerate when the DO(s) in your pond(s) starts to show significant depression at sunrise and/or sunset_ Generally, when the DO level drops to less than three and one half to four (3.5 - 4.0) ppm at sunrise or sunset, you will need to begin aeration procedures. Extensive pr oduc t ion aer ation ne e ds For extensive shrimp farming (in this case described as a density at or below thirty-two thousand (32,000) shrimp per acre (SPA) or, as it is sometimes referred to, -seven (-7) s hr imp per square y ard (SPSY)) y ou or dinar ily dn r o t need

to aerate your ponds. Normal oxygen transfer from the atmosphere to the pond water and that produced by the algae is generally adequate to meet the needs of the shrimp. Do not forget, however, that an occasional D O check can't hurt although, to be sure, there will be little you can do about a low DO problem. Exchanging the water will be your only reasonable recourse. Intensive pr oduc t ion a e r a tion ne e ds For intensive shrimp farming (described as a density at or between one hundred-sixty thousand (160,000) and sixtyfour thousand (64,000) SPA, or thirty-six (36) to -fourteen A-15

S hr im p R a nc h Ma na ge r T 74 (-14) SPSY) you will need to monitor the DO and mechardcally aerate your pond(s). A t these production levels (1,000 to 5,000 lbs/acre) you will need to monitor the DO in your pond(s) twice daily, AM and PM.

When we speak of aerators we are specifically referring to aerators that are generally called "paddle wheel" type units. These are surface units with paddle wheel-like configurations that splash and move the water. The following descriptions o f the Horse Power (HP) required for various crop densities apply only to this type of aerator. Should you choose to use aerators of a different type you will need to consult with the manufacturer of that device for HP sizing requirements. W e suggest the paddle wheel type of aerator from experience only: th e se units move a great deal o f water, thus mixing the pond water and exposing i t more frequently to the air wherein DO replenishment is accomplished. As a rule of thumb, you will need to apply two and one half (25) H P of aeration to every acre of pond in pr oduc tion

that has a harvest goal of five thousand (5,000) lbs/acre. I f your goal were ten thousand (10,000) lbs/acre, you would need fi v e (5) HP/ac r e .(2,500) W e lbs r /ac e r e y ou w ould need one and one quarter (1.25) t h e This is a fairly linear ratio between production HP/acre, g oandaaeration l goal needs. t w e n t y Production Goal / 2,000 .â&#x20AC;˘ HP/acre of aeration fi v e Now, mechanical equipment tends to fail. I f you have h ularger n than one (1) acre we strongly suggest that you ponds d r e have multiple aerators in those ponds. On e aerator still d running is way better than none! Fo r instance, in a two (2)

acre pond stocked to produce five thousand (5,000) lbs/acre

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A ppe ndix A H o w To G r o w Shr im p you would need a minimum of five (5) HP total aeration (10,000 / 2,000 = 5). The best configuration would be two (2), two and one half (25) HP aerators. Hyper shrimp farming (described as a density i n t Hyper-intensive en at or above one hundred-sixty thousand (160,000) SPA or sive thirty-six p r o (36) SPSY) requires aeration according to the above formula. As you increase your production goals it becomes d u ever more c t i critical that you monitor the pond(s) DO on a more o n frequent interval. As you approach ten thousand (10,000) a e lbs/acre (and greater) it becomes imperative that you the DO constantly. As may be seen from Figure r monitor a 6., t the i DO levels, even with constant and adequate aeration, often fall to dangerous levels every night. Failure of an o n aerator can have rapid and fatal consequences. n e DO levels rise during the daylight hours as the algae e the aeration serve to increase DO concentrations. A t and d sunset, the algae actually start to use DO and the overall DO s levels start to drop. You might note that around 3AM there is another sharp drop in DO, most probably due to vastly increased activity of the shrimp, which are nocturnal. Without adequate aeration the DO levels in a pond such as this co

CO 8 7 5

6— 5—

3 —2 —1

3 L2— 1— Sunrise

Surset

Fig. 6. Typical diurnal graph (wi t ) a e r infensive a t o r spond. O V ) o f D O f o r A-17 a h y p e r -

- 3 AM

S hr im p R a nc h Managerrm would easily fall to two (2) or even one (1) ppm and cause a complete "crash" of the pond, resulting in 100% loss of the (Top. Some manner of electronic monitoring and alarming system to warn of lethally low DO and/or failure of the mechanical aeration equipment is required to avoid this situation (see the SRM section of this manual). Fe e ding The brand of shrimp feed you select will most probably be dictated by price. We suggest no particular brand but rather its composition, which should be at least thirty-five percent (35%) protein. Some researchers have indicated that a protein content of less than 35% will work but we have no evidence of that. S a m pling the s hr im p Starting fi fth week after seeding, you should sample the shrimp population no less than once a week. Using a feed tray (as the shrimp get larger you can use a cast net), take at least three (3) samples of no less than twenty (20) shrimp each from three (3) different sites in your pond(s). Take each sample of twenty or so shrimp, weight it to the tenths (1/10s or 0.0) of a gram, add the nine (9) sample weights together and divide by the total number of shrimp from all nine (9) samples, for example: Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8 Sample 9 TOTAL WEIGHT Total # of shrimp

â&#x20AC;&#x201D;45.8 grams 46.8 grams 45_1 grams 44_0 grams = 46.7 grams = 44.5 grams = 42.0 grams = 43.8 grams = 47.1 grams = 405.8 grams = 187

405.8 / 187 = 2.17g average wt/shrimp (AW)

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A ppe ndix A H o w To C r o w S hr im p Week

2 3 4 5 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Survival Muttiplier 0.9500 0.9170 0.8830 0.8500 0.8476 0.8452 0.8429 0.8405 0.8364 0.8328 0.8293 0.8257 0.8197 0.8126 0,8055 0.7983 0.7896 0.7771 0.7650 0.7549 0.7448 0.7310 0.7161 0.7108 0,7053 0.7053

Table 1_ Survival table by week since seeding.

This value, e.g., 2.17g per shrimp will be used in either of the two (2) feed quantity methods described below

Extensive feeding requirements As stated earlier, extensive production does not require feeding the shrimp. Th a t is not to say that an occasional "pond feeding" will not be necessary: observation of the algal bloom may indicate a need for fertilizer periodically. Maintenance of the algae is as important for extensive production as it is for the other methods described in this manual and for the same reasons. A-19

Shr im p R a nc h M a na ge r . , Inte ns iv e fe e ding r e quir e m e nts The size of your shrimp will dictate the amount of feed you will give them, regardless of the method used to determine the amount of feed. This, of course, will mean that you will need to know the current average size of your crop, by pond. FEEDN,Q Regardless of whether you are involved . in intensive or hyper-intensive production, the first four (4) weeks of growth from the initial seeding has a fixed feeding regime. In as much as the shrimp are way to small to sample and are primarily "grazing" on available small plants, etc., the feed you add is really "feeding the pond", not the shrimp. Hence, as you will see, the feed suggested from the methods d e sfrom the seven point five per cent (7.5%) up listed c r i bfor e dthe fourth (4th) week below. This is normal. b e l Toh i swfixed system, based on the Percent w i Body l l Weight (PBW) concept, is as follows: " j u m p " Week PBTN 33c/0 2 1 5 % 3 7 . 5 % 4 7 . 5 % Use the above PBW numbers for weeks one through four (I-4) of the initial growing period to determine the feeding requirements While following the PBW math explained Starting with the fifth (5th) week after putting the PLs into your pond(s), you will want to use one (or both, as explained) of the two (2) methods used to determine the amount of feed to give to your shrimp, i.e., "Percent Body Weight" (PBW) and "Body Weight Gain" (BWG) A-20

Ap p e n d ix A H o w To G r o w Shr imp

Percent B ody We ight ( P B W) m e thod f or fe e ding This method of feeding is considered "responsive", i.e., knowing what size the shrimp are today dictates the feeding regime for the coming week. I t does not, as with the BWG method described later, presume a growth goal, rather it merely responds to current size of the shrimp and prescribes a week's worth feeding regime. We do not endorse one method over the other. Although the following math may seem somewhat complex it is necessary that it be used. Short of personnel, the single largest expense in shrimp farming is the cost of feed. Accurate feed estimations is critical. To o little and you won't realize the growth needed for profit. To o much and, of course, you are literally throwing money away. The BWG method is essentially a process of taking the average weight of the shrimp, which we will call Average Weight (AW) in this formula, and applying the AW to the formula: (18.325 - 3_9412* A W + 0.44346 * Aw2 - 0.026664*

AW 3 - 1 For our example, if the AW were 2.17 grams, the PBW would calculate out to 11.61%, or a multiplier of 0.116. 0 As was said, it is a complex formula. On ce the PBW has . been figured out you must then factor in the assumed sur0 vival, which may be gotten from Table 1, Assuming in this 0 case that we are in the sixth (6th) week of growth, the sur0 vival is estimated to be 84.05% 8 2 Had we put ten thousand (10,000) shrimp PLs into a 8 pond we would assume that there are now 8,405 (0,8405 * 6 10,000) shrimp still alive. 7 * Now, we take the total number of shrimp (8,405), multiM ply them by the AW (2.17), multiply that number by the A PBW (11.6%), convert to pounds (lbs) and we arrive at the "shrimp feeding requirements for each day for the coming -week (note that there are 454 grams in a pound): 0 A-21 . 0 0 0 0 1

S h r i m p R a n c h ManagerTH 8,405 * 2.17 AW

= 18,238.9 grams

18,238.9 *0.116 PBW

, 2,116 grams

2,116 / 454

= 4.7 pounds of feed/day

So, as you can see, we would feed the shrimp 4.7 pounds of feed each day for the next week. H a d we seeded 100,000 shrimp, this feed value would be 47 pounds, etc.. W AND BW It must be emphasized th a t the values derived from both the PBW and the BWG feeding regimes are ideal values and do not take other growing factors into consideration. These other conditions include, but are not limited to, health of the algae, weather conditions (cloudy and fo r how long), DO levels, production goals that are extraordinary and conditions th a t a n on-site biologist mi g h t deem important in "fine-tuning" the feeding of the shrimp. These conditions are outside the scope of this manual_ There are, however, some generalities you may wish to remember: • I f the days have been cloudy, reduce the feed and c arefully observe the DO levels

• I f the DO levels continue to be low (less than 4 ppm), reduce the feed some more • I f the DO levels are high (greater than 7 ppm), you may slightly increase the feed. Again, this is the most diffi cult math procedure the shrimp farmer must perform and, as was stated, it is the most critical. Attention to this routine will mean the difference between success and failure. This PBW feeding estimation routine applies whether you are using intensive or hyper-intensive production.

A-2 2

A ppe ndix A H o w To G r o w Shr im p As a final note, the Shrimp Ranch Manager (SRM) Software handles these feeding figures automatically. B ody We ight Ga in ( B WG) m e t hod for fe e ding This method of feeding is considered "anticipatory", i.e., you set a growth goal for your shrimp and then feed accordingly. For instance, today your shrimp are 2.17 grams and you would like for them to be 3.17 grams in one week, a 1 gram increase. The math for the feeding regime is simpler than that of the PBW method. Following the previously described sampling techniques you would arrive at an average weight (AW) which, in this case, we will assume to be as in the PBW case, i.e., 2.17 grams with the same survival, i.e., 84_05% or 8,405 shrimp. Today's A W

2.17 grams

Desired Weight = 3.17 grams fi gure desired w eight increase of 1 s hr imp 3.17g - 2.71g = L O gram increase fi gure total w eight increase 1.0g * 8,405 = 8,405 grams

Now, here we need to introduce another concept used in growing shrimp: the Feed Conversion Ratio (FCR). This is the v alue that represents the ratio between the amount of food the s hr imp convert into s hr imp meat. I d e a lly , the FCR y ou realize w ill be ar ound 2:1 (see NO TE: below) , i.e., for every pound of feed y ou add to y our pond w i l l res ult in a half (1/2) pound of s hrimp. A n FCR of 2:1 is v ery good.

Ordinarily an FCR of 2.5:1 or slightly higher is more normal, especially as you increase the density of the shrimp in your pond(s). In this example, we will assume an FCR of 2.5:1, or a not so great FCR for a hyper-intensive production pond.

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S hr im p R a nc h Managerna

As a general rule-of-thumb, ideal FCRs vary with the production method. For extensive production th e ideal FC R w o u l d be slightly less than 21, for intensive the ideal FCR would be at 2:1 and for hyper-intensive the ideal FCR would be slightly greater than 2:1_ To continue: allow for the FCR of 2.5:1 8,405g * 2.5 = 21,012.5 grams convert grams to pounds 21,012_5 / 454 = 46.28 lbs of feed/day figure daily feed requirement 46.28 / 7 days = 6.61 lbs per day feed For the sake of the example, w el l examine a different FCR of 2:1 (as for an intensive pond). allow for the FCR of 2:1 8,405g *2 = 16,810 grams convert grams to pounds 16,810 / 454 = 37.03 lbs of feed (1 wk) figure daily feed requirement 37_03 / 7 days = 5_29 lbs per day feed As y ou can see, the BWG feed quantity of 5..29 pounds

per pond per day is relatively similar to the PBW feed quantity of 4.7 pound of feed per pond per day, or 12%. Be aware of the difference between the PBW and the BWG methods of calculating daily feed needs of your shrimp. The PBW method more closely follows the actual growth patterns of the shrimp. Th e shrimp do not grow at a linear (straight line) fashion, which is to say, smaller shrimp do not grow as much (in grams per week) as larger shrimp.

The PBW method takes this variation in growth dynamics into account the BWG method does not. This difference becomes less pronounc ed as the s hr imp get larger than eight

to nine (8-9) grams. A-24

A p p e n d i x A H o w To G r o w S h r i m p Some shrimp farmers mix the PBW and BWG methods by following the PBW method from seeding to 1215 weeks of growth and then shift to the BWG method for the remainder of the grow-out. Whatever method you ultimately use, it will become easier for you to select a method as you gain experience. Careful sampling and observation are essential to your success. As a final note, because the feed companies most often used are not located in your back yard, it imperative that you take special care to know your feed inventory. N o t feeding your shrimp for even a day or two can have very negative effects on your crop.

Harvesting yo u r shrimp The when for harvesting your shrimp is predicated on a number of issues: th e current size of the shrimp, your financial riccds and the market. We will discuss these issues from last to first- The h c discussed last. Av o f T h hae rs hvr iem ps m t a i rket n g y Selling o ushrimp is easy. Getting a good price is not. A s with any commodity, pricing the product is a mix of science r and s magic, h r with a dash of luck. Wi th that in mind we will present the i m pvarious markets and the pros and cons of each. w i T h e easiest m arket l l b Selling your shrimp e forward, p o neasiest d - s and i d eleast " profitable. This market presumes that you intend to grow your shrimp to the maximum posi s sibletsize,hharvest e once and be done for the season. m o s t on a buyer and the price they will sOncet you r have a settled i pay,gits simply a matter of harvesting the shrimp, meeting h t the buyer's quantity requirements and packing them off without further ado.

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S hr im p R a nc h M a na ge r ' m This marketing method, which involves no "valueadding", will result in the lowest price per pound for your shrimp. Because you are selling the whole, or "heads-on" (HON) shrimp, the buyer will process (de-head and freeze or bread or otherwise prepare) the shrimp and take the profits for those efforts. The up-side, of course, is that you, the grower, are not required to perform those activities and incur the added expense that means. There are very few shrimp growers who are also in the business of processing the shrimp. Thus, most growers currently sell pond-side HON. The Liv e " Recently, at least in South Carolina, a live shrimp marm a developed that affords the grower an excellent market has rketkfor his product. Unfortunately, the market is, as of the edate t of this manual, rather small and cannot accommodate all the shrimp product state growers can produce. The beauty of the live market is that it prefers a smaller (30-40 count) shrimp and pays a premium price for the product. As a result, this market offers the grower at least the potential for more than one (1) crop per season since growing shrimp to the preferred size should take only three to three and one half (3-33) months (especially the "stylies"), thus allowing multiple crops (so long as the seed is available). Live shrimp buyers will pay up to twice the price for live shrimp that would otherwise be sold as HON pondside, assuming the same size/count for both markets. This market is generally located in larger cities but efforts are underway to create more local markets and increase the potential for sales. The loc a l "fresh, h e a d s FI-IOFF sales opportunities are diffio f f Exact T local H O M market " cult m toaproduce, r k butetheytdo exist and the prices are attractive. D ue primarily to the vastly reduced production of Ecuador and China, local (i.e., southeastern) FHOFF markets are more attractive. This market is also supplied by the "wild-catch" industry. A-26

A ppe ndix A H o w To G r o w Shr im p This market requires the producers to provide, or have provided, the necessary de-heading and icing procedures so that they may deliver to the customer an iced shrimp tail for their use. Thi s market is very attractive since, for the most part, the "middle-men" are eliminated allowing the grower greater profit opportunity. Similarly, the grower, should they decide to "spot harvest" their pond(s), can continually cull their inventory of shrimp and provide the customer with a more even supply of FHOFT shrimp. Thi s has the added benefit of reducing the density of the pond(s) which ordinarily causes accelerated growth by those shrimp left, thus replenishing the stock for the next culling. Y our fi na nc ia l ne e ds As is often the case, for the small to medium (and occas ionally large) s hr imp gr ower , a cash-fl ow crisis can occur. The temptations to start s elling off the s hr imp inv entor y at

whatever price can be had can be very attractive and maybe even necessary. We would not presume to anticipate your financial needs but we would offer these observations. It is generally unwise to sell off, prematurely, your crop (except, of course, to the liv e market). I t is obv ious that by depleting y our crop(s) before they have achieved an optim u m size y ou hav e greatly reduced the number of s hr imp that may get to that o p t imu m size. T o ex plain, t h e follow ing scenario is pr ov ided: s hrimp av ailable in pond 100,000 size at 1st depletion 1 2 grams weight s old at 12g 1 , 0 0 0 lbs

454,000grams

1,0001bs *4 5 4 g / lb 454,000 / 12g/ s hr imp 100,000 - 37,833

= 37,833 s hr imp s old = 62,167 s hr imp left.

A 12 gram shrimp fits into the 36-40 count area. Let's say that you received S IN /p o u n d for these shrimp: 1,000 *S2.20

$2,200.

A-27

S hr im p R a nc h Ma na ge r OK, now let's figure the value of the remainder of the crop, assuming that they are allowed to grow out to 185 grams, or the high end of a 21-25 count shrimp (24.5 shrimp per pound) and assuming you get $3.00 per pound: 62,167 / 24.5 shrimp/lb = 2,537.4 lbs 2,537.41bs *$3.00/1b = $7,612.29 Adding the $2,200 received for the first 1,000 pounds and the $7,61229 final harvest value yields $9,812.29 total crop value. Had you allowed the entire crop to grow to 18.5 grams, you would have seen: 100,000 / 24.5 ishrimp/lb , 4,081.6 lbs 4,081.6 *$3.00/1b , $12,244.90 calculate difference in earnings $12,244.90 - $9,812â&#x20AC;˘29 , $2,432.61 By selling off a portion of your crop early you will actually lose $2,432.61 in the end. O f course, after culling you would have had to feed the remaining crop less and that would reduce the loss. Survival and other production factors have not been figured into this example. The point is, early harvests cost you money unless you pursue one of the more lucrative markets described above. T h e c ur r e nt size of the s hr im p If you take into account all of the previous information concerning the market and your financial needs it should be apparent that the size of your shrimp is the primary consideration in selling your crop(s). As stated, selling smaller HON shrimp makes sense only if you are getting a premium price, as from live sales. By adding value, such as heading/icing/freezing/packing, you can also make a smaller shrimp more valuable but it will cost you more money. Finally, selecting the fastest growing s hr imp can help impr ov e early sales_ A- 28

A ppe ndix A H o w To G r o w Shr im p H ow to ha r v e s t y our s hr im p Harvesting your crop(s) will involve two factors: the

speed and the ease of harvest. As you might expect, the fastest and easiest method of harvesting is also the most expensive. B y utilizing a "fishpump" with de-watering box method, harvesting is less labor intensive, quicker and easier to control. A two (2) acre pond containing as much as twenty to twenty-five thousand (20-25,000) pounds of shrimp can be harvested in as little as twelve (12) hours. To harvest this same pond by any other method (bagnet, cast-netting, etc.) will increase the time needed, increase the labor required but decrease the cost of harvest. The method you choose is predicated on your financial situation.

A-29