The early mortality syndrome (EMS) in shrimp has been ravaging production systems, spreading vertically in Asia and horizontally to countries as far away as Mexico since first reported in 2009.

1. I N C O R P O R AT I N G
f i s h far m ing t e c h no l og y
January | February 2014
EXPERT TOPIC - SHRIMP
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The International magazine for the aquaculture feed industry

2. EXPERT T●PIC
EXPERT TOPIC
SHRIMP
Welcome to Expert Topic. Each issue will take an in-depth look
at a particular species and how its feed is managed.
42 | InternatIonal AquAFeed | January-February 2014

3. EXPERT T●PIC
1
3
2
1
Global
EMS Impact on global
shrimp industry and
future prospects
by Dr Farshad Shishehchian, president
and CEO of Blue Aqua International and
president-elect of the Asia Pacific Chapter
of the World Aquaculture Society
T
he early mortality syndrome (EMS)
in shrimp has been ravaging production systems, spreading vertically in Asia and horizontally to
countries as far away as Mexico since first
reported in 2009.
Looking at the impact of EMS on the three
largest global shrimp producers – Thailand,
Vietnam and China - there have been substantial effects on supply and prices to the
global shrimp market.
"Thailand used to be the largest shrimp
exporter with over 500,000 metric tonnes of
shrimp production.
"In 2013, its production fell almost 50 percent from the previous year because of EMS.
This offers a window of opportunity for other
potential shrimp producers such as Indonesia,
India and Ecuador. Indonesia farmers have
experienced the highest profit record in their
shrimp history as a result.
"Culture expansion is putting in full force
during this lucrative period. India is another
potential producer to
keep an eye on. Since the
permission of vannamei
culture a few years back,
India increased its shrimp
production by more than
two fold last year. Ecuador
is pushing with much higher production in the past
two years."
In conclusion, and due
to the impact of EMS, Dr
Shishehchia says shrimp
Dr Farshad Shishehchian President and CEO of Blue
prices will continue their
Aqua International and President-elect of the Asia
high level for some time
Pacific Chapter of the World Aquaculture Society
because of the insufficient
(right) with Tuti Tan of International Aquafeed
supply.
magazine, Roger Gilbert President of Association
"This is likely to conof Sdeafood Professionals and publisher of IAF and
Nun Chongwitookit, Marketing Communications
tinue until Thailand, the
at Blue Aqua International during the APA13
world’s leading shrimp
exhibition in Ho Chi Minh City, Vietnam in
exporter and most techDecember 2013
nologically advanced producer, gets into recovery
mode and creates a shift in supply and prices." corporation with International Aquafeed
However, the long-term impact will be and the Association of International
consolidation and integration of shrimp farms. Seafood Professionals is organising a EMS
The current disease situation and environ- Forum: 'Managing the Shrimp Epidemic' in
ment will push for consolidation in the mar- terms of bringing practical solutions to the
ket. Small farms without aquaculture practice shrimp industry. The forum will be held on
standards and sufficient funds will be driven March 28-29, 2014 at KU Home, Kasetsart
out of the business. Those large farms with University, Bangkok, Thailand. This event
strong finance, good farm management, low is supported by Department Fisheries of
cost, high access to markets will be the future Thailand, Department Fisheries of Indonesia,
of the shrimp industry, he adds.
Shrimp Club of Indonesia (SCI) and Blue Aqua
International. Participants are expected from
India, Vietnam, Malaysia and Mexico in addiEMS Forum
Asian Aquaculture Network (AAN), in tion to Indonesia and Thailand.
January-February 2014 | InternatIonal AquAFeed | 43

4. 2
EXPERT T●PIC
Biofloc systems
Using super-intensive
biofloc systems for Pacific
white shrimp production
by Tzachi Samocha, Terryl Hanson,
Timothy Morris, Vitalina Magalhães, Bob
Advent and André Braga, Texas A&M
AgriLife Research Mariculture Lab, Flour
Bluff, Texas, USA
T
he demand for protein by an
increasing world population –
together with decreasing harvests
from fisheries – has resulted in
rapid growth of aquaculture. Global aquaculture currently accounts for 40 percent of
seafood production and provides 60 percent
of shrimp demand. The world shrimp farming
industry’s annual growth over the last decade
has been estimated at 10 percent. The rapid
expansion of this industry has stimulated the
intensification of production systems, which
has unfortunately resulted in the release
of nutrients and organic waste, and sometimes the spread of diseases, all damaging
receiving streams. Uncontrolled growth has
imposed heavy losses, and raised major
criticisms that threaten further development
of the industry. To reduce losses to disease
outbreaks, producers have been looking
for more sustainable and cost-effective
practices.
Despite the world trend in favour of
aquaculture, in the United States the sector
has shown no substantial growth. The country
thus remains a net seafood importer, with
annual shrimp imports of 1.2 billion lbs
worth $4.5 billion. New approaches must
be devised if US shrimp farming is to avoid
the environmental drawbacks of traditional
flow-through ponds. US systems must have
a very low impact on the environment and
fully contain – rather than export – any
water quality or disease problems that
arise. One approach is to shift from lowintensity outdoor ponds to super-intensive
indoor recirculating aquaculture systems
(RAS). With little or even
table 1. litopenaeus vannamei performance in a 92-d growno water exchange, properly
out trial in four 40 m3 rWs stocked with juveniles (1.2 g) at a
density of 530/m3 and operated with no water exchange
managed RAS thus reduces
or eliminates the amount of
Water Use
Sur.
Wt
Growth
Yield
nutrients released to the enviFCr
(l/kg
ID
3)
(%)
(g)
(g/wk) (kg/m
Shrimp)
ronment, escape of non-native
culture species, and spread
St 18.45a 1.27
8.96
84.4 1.28
148
of pathogens to the environment. Because of these factors
FF 17.35b 1.26
8.24
80.2 1.35
149
they easily conform to effluent
standards set by the national
* Values with different superscript letters indicate stat
regulator.
Biofloc technology (BFT)
table 2. Summary of a 108-d grow-out study performed in
systems are a special type of
2009 with juveniles (0.99 g) litopenaeus vannamei stocked at
RAS that maintain a commu450/m3 under no water exchange
nity of suspended (flocculated)
av.
o2
Growth Survival
Yield
microalgae and autotrophic
Usage
Wt.
tank ID
FCr
and heterotrophic bacteria
(lPM)*
(g)
(g/wk)
(%)
(kg/m3)
(“biofloc”) together with the
shrimp in limited-exchange
rW (St) 21.88
1.37
94.5
9.43
1.58 0.17
grow-out units. Pacific white
shrimp (Litopenaeus vannarW (FF) 22.45
1.37
96.6
9.63
1.55 0.27
mei) growth rates are much
higher in BFT systems than
in clear-water systems, and higher still at costs in shrimp production, accounting for
greater floc levels. The composition of the over 50 percent of the total production costs,
biofloc affects nutrient cycling. Heterotrophs it can significantly affect profitability. The
and autotrophs are preferred in floc systems interactions between feed, water quality and
because they provide two very important productivity have been evaluated in relation
services: they assimilate ammonia and nitrite to the characteristics of each culture system
(both highly deleterious to shrimp), and act as resulting in the development of specially
a supplemental feed.
designed feeds to enhance shrimp performance in each system.
The effects of commercial feeds on water
Biofloc success: a water
quality and shrimp performance are important
quality issue?
Feed and feeding practices are important factors affecting feed formulations. The end
factors affecting water quality and profit- product of feed catabolism is ammonia, which
ability of any aquaculture operation, moreso can be toxic to shrimp. Ebeling et al. describe
when dealing with hyper-intensive, biofloc- three pathways for ammonia removal in tradidominated systems. As mentioned above, tional aquaculture systems: photoautotrophic,
shrimp can derive nutritional benefits from the autotrophic and heterotrophic. The dominant
microbial aggregates in BFT systems. Studies in of these pathways in BFT systems can be
our lab also showed good shrimp growth (2.4 affected by biotic and abiotic factors.
With an adequate supply of organic
g per week) and survival (96.8 percent) when
5 percent of the fishmeal in a 35 percent carbon, heterotrophic bacteria can quickly
crude protein diet was replaced with biofloc. convert (in around 8 hours) all available
However, this replacement resulted in a ammonia into bacterial biomass, a process
reduction in shrimp growth (0.4 g per week) which requires a large amount of oxygen and
compared to the control diet with no fishmeal the generation of high volume of bacterial
replacement. Analysis of the biofloc produced biomass. On the other hand, when organic
in our system suggested low protein (20.4 carbon is provided solely from feed, any
percent), low fat (0.29 percent) and high ash ammonia not consumed by the heterotrophic
bacteria will be slowly converted into nitrate
(43.4 percent) content.
Because feed represents one of the major by autotrophic bacteria. This nitrification proctable 3. Combined mean production values from two grow-out studies conducted in 2011 with
juveniles litopenaeus vannamei from Fast-Growth (a) and taura resistant lines (b) in the 40 m3 and
the 100 m3 raceways.
System
Density
n
Volume
(shrimp/m3)
Salinity
(ppt)
Initial
Wt. (g)
Final
Wt. (g)
Days
Growth
(g/wk)
Sur.
(%)
Yield
(kg/m3)
FCr
40 m3 4
500a
18
1.9
23.2
82
1.82
82.3
9.5
1.43
40 m3
1
500a
30
1.4
25.1
85
1.95
78.9
9.9
1.44
100 m3
2
390b
30
3.1
25.3
106
1.46
83.0
8.4
1.77
44 | InternatIonal AquAFeed | January-February 2014

5. EXPERT T●PIC
Figure 1: Ammonia-N (100 m3 RWs)
Figure 2: NO2-N (100 m3 RWs)
Figure 4: Alkalinity (100 m3 RWs)
Figure 3: NO3-N
(100 m3 RWs)
Figure 5: Turbidity (100 m3 RWs)
ess, which consumes alkalinity as an inorganic
carbon source, requires far less oxygen and
produces around 40 times less bacterial biomass than the heterotrophic pathway. When
operating biofloc systems under low light
intensity with restricted organic carbon supply,
autotrophic and heterotrophic bacteria will
dominate the microbial populations. These
mixotrophic systems require careful monitoring and control of selected water quality to
maximise production.
2007-2011: early studies
In recent years, studies at the Texas
A&M AgriLife Research Mariculture Lab have
focused on the use of a commercial feed
made by Zeigler Bros. (HI-35, Zeigler Bros.,
Gardners, PA) formulated for use in highdensity, biofloc-dominated no-exchange systems for the production of market-size L.
vannamei. These studies were conducted in
four to six greenhouse-enclosed 40 m3/68.5
m2 raceways. Each lined raceway is equipped
with a centre longitudinal partition positioned
over a 5.1 cm PVC pipe with spray nozzles.
Every tank had six banks of three 5.1 cm airlift
pumps positioned equidistantly on each side
Figure 6: TSS (100 m3 RWs)
Figure 7: VSS (100 m3 RWs)
Figure 8: SS (100 m3 RWs)
of the partition. In addition, each raceway had
six 0.91 cm long air diffusers, a 2 hp centrifugal
pump, and a Venturi injector capable of introducing atmospheric air or a mixture of oxygen
and air. The following is a short summary of
the progress made in operating this system
over the last six years.
The 2007 study was conducted in four of
the raceways described above, which were
equipped with the YSI 5200 inline dissolved
oxygen monitoring system. The tanks were
stocked to a density of 530/m3 with 1.2 g
juveniles using water from a 77-day nursery
trial. The study compared two methods of
biofloc control: homemade foam fractionators
and settling tanks. Shrimp were fed on the
HI-35 feed mentioned above. Until Day 73
(estimated 7 kg shrimp/m3), oxygen demand
was met solely by the Venturi injector and
atmospheric air. From Day 74 on, atmospheric air was enriched with pure oxygen.
The dissolved oxygen monitoring system was
instrumental in managing feed and preventing
low oxygen events. All shrimp submitted for
disease diagnosis showed no signs of viral
infections. The results from this trial are summarized in Table 1.
In 2009 a second study was conducted to
determine whether or not smaller commercial
foam fractionators (in the case, Aquatic Eco
A two-day VietFish Conference ‘Fishfarm Management & Fish Marketing’ - August 7 & 8, 2014
Organised on behalf of VietFish 2014 by the Association of International Seafood Professionals (AISP) and
International Aquafeed magazine
Vietnam, with its population base of 90 million people, produces for domestic markets and export markets
US$6.7 billion of farmed fish products. Of its exports 21 percent goes to the EU, 19 percent to the USA
and 16 percent to Japan. Currently, Vietnam exports 40 percent of its shrimp production and 30 percent
of its Pangasius. Vietnam is aiming at achieving food security in fish by 2020. The industry faces challenges
in the area of disease, production costs, meeting market requirements, financial resources and value chain
developments. This conference aims to address several of these
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www.en.vietfish.com.vn
January-February 2014 | InternatIonal AquAFeed | 45

6. EXPERT T●PIC
biomass loading
table 4. Summary of mean final weight, weekly growth, yield, survival,
(> 6 kg/m3). Each
FCr, and water usage from a 67-d grow-out study of litopenaeus
tank was equipped
vannamei in 40 m3 greenhouse-enclosed raceways operated with no
water exchange.
with 14 injectors,
and one injector
Yield
Survival av. Wt. Growth
Water Use
powering a homeFeed
FCr
made foam frac(kg/m3)
(%)
(g)
(g/wk)
(l/kg shrimp)
tionator for biofloc
control. Raceways
HI-351
9.74
87.3%
22.12
2.03
1.25
124.7
were stocked to a
density of 270/m3
SI-352
8.71
88.3%
19.74
1.76
1.43
138.3
with 8.5 g juveniles
Diff
1.03
2.38
0.27
0.18
13.6
and were fed the
Zeigler Bros. HI-35 1RWs where shrimp were fed the HI-35 Zeigler Bros. feed
feed. At the end 2RWs where shrimp were fed the SI-35 Zeigler Bros. feed
of the 87 days of
the 2010 trial, a
yield of 6.4 kg/m3
table 5. Summary of litopenaeus vannamei) performance following a
was obtained from
63-d grow-out period in two 100 m3 raceways using the a3 injectors for
mixing and aeration.
marketable shrimp
(26.1 g), with 90.1
Stocking
Harvest Growth Survival Yield
Water
percent survival
FCr
Use
rate and a feed rW (Juveniles
(g)
(g)
(g/wk)
(%)
(kg/m3)
(l/1 kg)
/m3)
conversion ratio of
2.46.
The trial in 2011
1
500
3.6 22.76 2.13
80.82
9.20 1.43 139.5
was conducted
in five of the 40
2
500
3.6 22.67 2.12
78.19
8.86 1.53 148.9
m3 raceway tanks
average
22.72 2.12
79.50
9.03 1.48 144.2
described above,
filled with a mixture
of seawater and biofloc-rich water previously throughout the 106-day duration of the study.
used in a 42-day nursery trial. Salinity in four of The results are summarised in Table 4.
the tanks was adjusted to 18 parts per thousand using chlorinated municipal freshwater. 2012: trials point to
Raceways were stocked to a density of 500 commercial viability
shrimp/m3 with 1.90 g juveniles. For compariThe studies in 2012 used both systems for
son, a fifth tank was operated with salinity of the production of marketable shrimp. The first
30 parts per thousand, and stocked with 1.40 study was conducted in six 40 m3 raceways
g juveniles stocked at a density of 500/ and had four objectives:
m3. All raceways were stocked with
1. Evaluate the effect of two commercial
table 6. Summary of production and sales for
feeds on juvenile shrimp produced
shrimp from a Fast-Growth line providsuper-intensive biofloc dominated no exchange
from a cross between Fast-Growth and
ed by the Oceanic Institute, Makapuu
shrimp production systems comparing the results
from the 2011 trial to the 2012 trials.
Taura-Resistant lines
Point, Hawaii. Shrimp were fed the
2. Monitor the changes in selected water
same HI-35 feed as in previous studies.
HI-35
SI-35
HI-35
quality indicators under no exchange
The raceways were operated with no
100
treatment 2011
3 40 m3
40 m
m3
3. Monitor L. vannamei performance under
water exchange throughout the study.
high density and no exchange
Results from this study showed high
4. Evaluate the benefit of using the YSI
yields of food size shrimp, with good
Stocking density
500
500
500
500
5500 continuous dissolved oxygen
growth, survival and FCR (see Table 3).
(Juvenile/m3)
0%
0%
0%
monitoring system with optical probe
The second 2011 trial was conductSurvival rate
87.3
88.2
79.5
81.6
in operating a biofloc-dominated, supered in the two 100 m3 EPDM rubber(%)
+7.0% +8.1% -2.6%
intensive shrimp production system
lined raceways, each filled with a mixGrowth rate
2.03
1.76
2.13
1.85
The second study took place in the two 100
ture of seawater, municipal chlorinated
(g/wk)
+9.7% -4.9% +15.1%
freshwater, and biofloc-rich water from m3 raceway tanks and had three objectives:
Stocking size
2.7
2.7
3.6
a previous nursery study. The tanks
1. Evaluate the performance of the same
1.8
(g)
+50%
+50% +100%
were stocked with 390 shrimp per
juvenile shrimp used in the previous
Harvest size
22.3
19.8
22.7
m3, with Taura-resistant L. vannamei
study under the same stocking den23.6
(g)
-5.5% -16.1% -3.8%
sity when fed the HI-35 feed under no
juveniles (1.90 g) supplied by Shrimp
1.25
1.43
1.48
exchange
Improvement System, Florida. Shrimp
FCr 1.43
-12.6%
0%
+3.5%
2. Further evaluate the ability of the a3
were fed the same HI-35 feed used
Crop length
67
67
63
in previous studies. Raceways were
injectors to maintain adequate mix83
(days)
-19.3% -19.3% -24.1%
equipped with the YSI 5200 dissolved
ing and dissolved oxygen levels in a
9.74
8.71
9.03
Production
oxygen monitoring systems and were
high-density, biofloc-dominated, zero9.58
+1.7% -9.1%
-5.7%
(kg/m3)
maintained with no water exchange
exchange conditions
Systems’ VL65 fractionator) could be used
to minimise the differences in shrimp final
weights observed in the 2007 study. The 108day study was conducted in the same four 40
m3 raceway tanks equipped with the previously described YSI 5200 dissolved oxygen
monitoring system. Raceways were filled with
water from a preceding 62-day nursery study,
and stocked to a density of 450/m3 with 0.99
g juveniles. Freshwater was added weekly to
offset water losses. Shrimp were fed the same
HI-35 feed mentioned earlier. Settling tanks
and the foam fractionators were operated
intermittently, targeting total suspended solids
concentrations between 400 and 600 mg/L.
The results showed no significant differences
in shrimp final weights between the raceways
operated with settling tanks and those operated with foam fractionators. Furthermore, no
statistically significant differences were found
in shrimp performance between treatments
(see Table 2).
In an effort to reduce production costs
(e.g. the use of pure oxygen and electricity)
the lab began to test non-Venturi injectors for
aeration and mixing in two 100 m3 raceways
under biofloc conditions. These injectors (a3,
All Aqua Aeration) are currently used in
several wastewater treatment facilities in the
United States and require little maintenance
compared to other aeration and oxygenation
methods. This technology may be successfully
transferred to biofloc and other types of aquaculture systems. Based on the manufacturer’s
specifications, the injector provides a 3:1
air-to-water ratio, compared with the <1:1
capacity of our Venturi-driven system, which
requires the use of pure oxygen to maintain desired dissolved oxygen levels at high
46 | InternatIonal AquAFeed | January-February 2014

7. FEATURE
EXPERT T●PIC
helpful tool in increasing the moisture content
3. Evaluate the benefit of using the YSI 5200
allowed by the minimum water activity.
continuous dissolved oxygen monitoring
Moreover, the water isotherm and moissystem in operating the system
ture sample data can be used to calculate the
We also aimed at reducing FCRs below
moisture target and the upper control limit.
the values achieved in the previous trials,
For most dried products, the portion of the
primarily through continuous feeding.
isotherm at and well below the critical water
The six 40 m3 raceway tanks were filled
activity value of 0.65 is linear, giving a proporwith a mixture of water used in a preceding
tional relationship between water activity and
49-day nursery study, seawater and municipal
moisture content. A simple linear equation
freshwater to reach a salinity of 30 parts
can therefore be used to determine the water
per thousand. Each tank was equipped with
activity value from the moisture content, or
a small commercial foam fractionator and a
vice versa. The isotherm Shrimp used in this
homemade settling tank. in Figure 1 shows
that a moisture content of 8.92 percent will
study were produced from a cross between
give a water activity of 0.65. For this product,
Taura-resistant and Fast-Growth genetic lines
then, 8.9 percent would be the upper control
developed by Shrimp Improvement Systems.
limit.
Raceways were stocked with 2.66 g juveniles
at a density of 500 shrimp/m3. The study was
Sample variance
performed with three replicates using a semi-
The target moisture value must also take
intensive feed (SI-35) which had 35 percent
into account variance between samples. Here,
crude protein, 7 percent lipid and 4 percent
the moisture sample history can be used to
fibre, and a hyper-intensive feed (HI-35) with
calculate a standard protein, 7 ±3 standard
35 percent crude deviation: percent lipid
deviations 2 percent average will produced by
and only from the fibre, both account for
nearly 100 percent of samples. The moisture
Zeigler Bros.
target can then be calculated using the upper
The raceway tanks were maintained with
control limit and the number of standard
no exchange throughout the study and freshdeviations required. to compensate for water
water was added
Target moisture = UCL – N(s.d.)
losses. Oxygen supplementation was initiated
UCL: Upper control limit
on Day 17 and continued until termination.
N: No. of standard deviations
The YSI 5500 monitors and their optical
s.d.: Standard deviation of the product samples
probes allowed trouble-free, real-time oxygen
To give an example, using a standard As seen in the equation above, a reduction
supplementation
table 7. Summary of production and sales for deviation will result in an
deviation of 0.6 and the above upper control in the standard the extrapolated commercial
while
avoidscale super-intensive biofloc dominated no exchange shrimp production
limit excess use.
increase in the target moisture. The results
ing of 8.9 percent, and three standard results compared to three 2012 trials.
operation, with 2011 trial
deviations, you would receive a target mois- of this are increased production and energy
Concentrations
SI-35 40
HI-35 100
ture total ammo- percent. With current 2011
savings. HI-35 40
of level of 7.12
3
m3
m3
dryer control methods, only 0.14 percent
Assume, m for example, that through
nia-nitrogen
of moisture samples would have a chance improved dryer control the standard deviaremained
Production, kg/crop
38,960
34,840
36,120
of exceeding the upper control limit. Many 38,320
tion was reduced by 30 percent, to 0.42 (see
below 0.5 mg/L
users of statistical process control methods 4.4
Table 3). The new target moisture would
throughout the
Crops per year
5.5
5.5
5.8
will use 2 or 2.5 standard deviations in the be 7.66 percent, 0.54 percent higher than
study,
while
Production,
214,280
191,620
209,496
target moisture calculation, giving kg/year of 168,608
targets
the previous figure of 7.12. As this shows,
NO 2-N level
214
192
209
7.42 percent and 7.72 Productionrespectively 169
percent Mt/year
improved dryer control – obtained by drying
remained below
(see Table 2). The key values here are the 7.20 cooler temperatures and being careful
with
1.22 mg/L with
Selling price, $/kg
7.20
7.20
7.20
percentage of samples that may be statisti- not to over-dry the product – can allow a safe
no significant total Sales per year, $ 1,213,978 1,542,816 1,379,664 1,508,371
cally above the upper limit.
increase in average moisture levels, resulting
differences
in a 0.5 percent production increase. Cooler
between treattable 2: Results of altering the number of
final weights, yields, growth, and FCR for the
ments. While solids were controlled by the drying temperatures would also result in
standard deviations on target moisture
shrimp fed with the HI-35 feed. This study
use of the foam fractionators and settling energy savings.
calculation
tanks, levels of total suspended solids, turbid- showed that market-size shrimp can be protable 3: Number of standard deviations vs
number
ity and volatile suspended solids levels in the duced with no water exchange, and although
%
target moisture, with improved standard
of
SI target UCl remained Standard above
treatment
significantly higher the cost difference between the HI and SI
moisture
standard deviation
deviation values
UCl
than the HI treatment. These results may be feeds was significant ($1.75/kg vs. $0.99/kg), a
deviations
related to the higher levels of non-digestible preliminary profitability analysis indicates that
number
components in the SI-35 feed fibre and ash. both feeds would be commercially viable with
target
of
Standard % above
the profit advantage in favor of the HI feed.
Oxygen use for the HI treatment 0.14 21 moisture UCl standard deviation UCl
was
7.12 8.92
3
0.6
The second deviations 63 days and was
trial lasted
percent lower compared to the SI treatment
7.42 8.92
2.5
0.6
0.62
and the volume of water used to produce conducted in the two 100 m3 raceway tanks
7.72 8.92
2
0.6
2.28
1 kg of shrimp was slightly lower for the HI described earlier. The tanks were initially
With a method
treatment than the SI. of calculating target filled with a mixture of seawater, municipal
7.66 8.92
3
0.42
0.14
moistures and upper control limits in place, chlorinated freshwater, and biofloc-rich water
Analyses of shrimp performance based
7.87 8.92
2.5
0.42
0.62
we can give attention Table 4) showed no from a previous nursery study. Whereas the
on harvest data (see to optimising dryer
8.08 8.92
2
2.28
control to reduce the moisture variance. juvenile shrimp (3.14 g) in 0.42 2011 study
differences in survival rate, but better mean
the
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January-February 2014 | |InternatIonal AquAFeed | |13
January-February 2014 InternatIonal AquAFeed 47

8. EXPERT T●PIC
ture lab have been very
encouraging. Production
results for the best trial
run in 2011 and the
SI-35
HI-35
three trial runs in 2012
40 m3 100 m3
are presented in Table
6. Using production
results and extrapolating
7.20
7.20
them into the context
4.54
4.31
of a commercial facility,
2.66
2.89
10-year cash flows and
enterprise budgets were
0.53
0.48
developed to provide
5.07
4.79
comparable financial
2.13
2.41
indicators of profitability (cost of production,
1.9
1.6
net return, net present
2.0
2.6
value, internal rate of
50.1
60.6
return, and payback
period).
For this hypothetical analysis one greenhouse system contains 10 raceway tanks: eight
500 m3/m2 raceways for grow-out, and two
500 m3/m2 raceways for the nursery phase to
culture ten-day-old postlarvae to the 2.7 g or
3.6 g juvenile shrimp used in our simulations.
Analyses include a fixed cost component covering construction, equipment and machinery
costs of around $992,000. Other critical prices
and costs include shrimp selling price ($7.20/
kg), feed cost ($1.75 and $0.99/kg), juvenile
production costs ($20 per thousand), and an
interest rate of 8 percent for operating, equipment and construction loans. The economic
questions to be answered by this analysis are:
• Whether the production results are
financially positive, given that one feed
is much more expensive than the other
feed
• Whether progress was made between
the 2011 and 2012 trials in improving
the profitability of these super-intensive,
recirculating, biofloc shrimp production
systems
Table 6 summarises the production and
sales for the 2011 trial compared to 2012
trials.
Table 8 summarises the enterprise budget
based on 2011 and 2012 results, and indicates a positive net return per kilo of shrimp
table 8. Summary enterprise budgets for the super-intensive biofloc
dominated no exchange shrimp production systems comparing the
best 2011 trial with the three 2012 trials, in $/kg.
2011
HI-35
40 m3
Gross receipts
7.20
7.20
Variable Costs
5.38
4.06
Income above Variable Cost
1.82
3.14
Fixed Cost
0.59
0.47
total of all Specified expenses
5.97
4.53
net returns above all Costs
1.23
2.67
Payback period, years
2.9
1.4
net present value ($ mil.)
1.0
2.9
Internal rate of return (%)
31.3
66.6
were of a Taura-Resistant strain and stocked
at 390 juveniles per m3, the shrimp (3.60 g)
used in the current study were a cross produced from Taura-resistant and Fast-Growth
genetic lines, stocked at a density of 500
per m3. The shrimp were fed a HI-35 feed
using four 24-hour belt feeders for each
raceway. The tanks were maintained with no
water exchange and freshwater was added
weekly to maintain salinity and compensate
for evaporative losses. Mean water temperature, salinity, dissolved oxygen, and pH levels
were 29.6 °C, 29.3 ppt, 5.5 mg/L, and 7.1
respectively. Total ammonia nitrogen and
NO2-N remained low throughout the study,
<0.6 mg/L and <1.5 mg/L respectively, while
NO3-N increased from 67 mg/L at stocking
to an average of 309 mg/L at harvest. Shrimp
were harvested using a Magic Valley Heli-Arc
mechanical harvester. The study results are
summarized in Table 5.
Analysis: promising results point
towards production refinements
Production of shrimp in indoor superintensive recirculating systems can produce
large quantities of shrimp but can have high initial investment and operating costs. Economic
analyses of the 2012 trials in the two production systems used by the Texas A&M maricul-
48 | InternatIonal AquAFeed | January-February 2014
produced. The three 2012 trials had lower
variable production costs than the 2011 trial’s
variable cost. Likewise, the payback period
was less for these same trials than for the
2011 trial. All NPVs were two to nearly three
times greater than the 2011 trial, and the IRR
for the 2012 trials were much higher than the
ROI for the 2011 trial. Thus, the answers to
the two economic questions posed earlier,
are:
• The more expensive HI-35 feed financially outperformed the lower-priced
SI-35 in the 40 m3 and 100 m3 trials
• The improvements on the 2011 trials
made for 2012 resulted in a much better
financial performance
Now, the old adage ‘if it looks too good to
be true, it probably is’ may be at work here.
The highly favourable financial results from the
2012 trials need to be accepted with care as a
couple of major assumptions are being used in
this type of analysis. First, the model assumes
there is a readily available year-round ten-dayold postlarvae supply (which may be difficult
to achieve in the continental United States),
and secondly, research trials using these systems have yet to actually conduct back-toback-to-back production cycles. Water re-use
issues should also be taken into account (e.g.
for how many production cycles the same
water can be used until complete replacement or major polishing is needed to maintain
balanced ionic composition). Also, the energy
use to produce 1 kg of shrimp in each system
will have to be evaluated to determine which
system is more economically viable.
Although one research crop per year is
an accomplishment, to actually produce 5.8
crops per year (the result for the HI-35 100
m3 trial) with the same high level of output is
much more difficult to achieve. These caveats
are large and need to be addressed. However,
in the meantime the financial analyses conducted here using a tested bio-economic
model, together with current positive research
results, can help researchers focus their efforts
on the factors where improvement will provide the most return, helping to sharpen the
competitiveness of these intensive biofloc
shrimp systems.

9. LINKS
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I N C O R P O R AT I N G
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Successful moisture
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Current challenges and opportunities
in amino acid nutrition of salmonids
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