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Spring 2002 Newsletter
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FORMATION OF THE ASSOCIATION
The U.S. Freshwater Prawn And Shrimp Association was formed
on January 22, 2002. “The Association’s formation is
timely considering the industry is about to take flight since
proven growing methods are paying off,” stated Louis D’Abramo,
Professor at Mississippi State University.
Growers from seven states were represented and personal from
Kentucky State University, Mississippi State University, University
of Arkansas, University of Alabama, University of Georgia and
the University of Tennessee were present. The meeting began with
the formation of the Association and a Grower’s Workshop
was presented by Extension personnel.
Officers
President – Steve Fratesi
Vice-President- Richard Tindall
Sec/Treasurer – Kasha M. Cox
Board of Directors
Jane Corbin – TN Jackson Currie – AR
Clay Gutierrez – MS Jack Huerkamp – MS
Dolores Fratesi – MS Ricky Hargroder – AL
Pete Reems – GA David Marsh – KY
PURPOSE OF THE ASSOCIATION
“This non-profit Mississippi corporation is formed for
the purpose of assimilating and disseminating information to
its members pertaining to permitting, licensing, spawning, hatching,
producing, harvesting, transporting, stocking, management, and
marketing of farm -raised prawn and shrimp and to assimilate
and disseminate information pertaining to any thing incidental
thereto; to associate its members together as a business league
for the mutual exchange of ideas; to encourage and promote educational
programs pertaining to farm-raised prawn and shrimp production
and management; to encourage and promote the establishment of
sound farm-raised prawn and shrimp production and marketing operations;
to promote the development of farm-raised prawn and shrimp production
as a thriving commercial development for the benefit of the individual
members and for the economic benefit of the citizens and people
of the U.S.; and do any and all acts and deeds necessary and/or
incidental to the accomplishment of the above and foregoing purposes."
“By-Laws USFPSA”
PRAWN FARMING RECOMMENDATIONS & PREPARATIONS FOR 2002
GROWING SEASON
From the Kentucky State Aquaculture Newsletter
Dr. Bob Durborow – bdurborow@gwmail.kysu.edu – (502)
597-6581
During the last year or two prawn farmers have been increasing
their stocking and feeding rates in order to increase production.
This more aggressive approach to production requires a much more
aggressive approach to water quality testing and overall pond
management. Probably the four main factors causing prawn losses
were high pH, low dissolved oxygen, high ammonia, and high nitrite.
The following recommendations are designed to prevent these things
from happening this year. Many of these recommendations come
from a recently published book (2000) entitled Freshwater Prawn
Culture—The Farming of Macrobrachium rosenbegii by Michael
New and Wagner Valenti. Purchasing information can be found online
at www.was.org.
Liming needs— The total alkalinity of pond water helps to
buffer (prevent changes in) pH. Because high pH values around
9.5 to 10 and above can kill prawn, it is important to have enough
total alkalinity (buffering capacity) in the water to prevent
these high pH levels from occurring. Some waters may have a total
alkalinity and total hardness concentrations less than optimum
for prawn. To correct this, agricultural limestone should be
applied to the dry pond bottom or over the surface of the water
to increase total alkalinity to 50 parts per million. There are
several types of liming materials, the most common being agricultural
limestone. In prawn culture, ag lime should be applied if waters
contain less than 30 to 40 ppm total alkalinity. Waters containing
over 60 ppm total alkalinity probably should not be limed, because
the limestone will not dissolve. As an alternative to measuring
the lime requirement one may apply lime to ponds at rates similar
to those used on agricultural soils used on agricultural soils
in the surrounding area, but application rates normally should
be at least 500 lbs/acre, and usually 1,000 lbs/acre is required
for a good response. Liming should be done in the fall or winter
before the shrimp are stocked (that means now if your pond needs
it!!!). This gives the limestone time to dissolve and interact
with the pond muds before the fertilization begins in the spring.
Choose the finest, most pulverized agricultural limestone that
you can find (liquid limestone is also effective). Do not use
hydrated or quick limes because their effects are short-lived
and they can cause sudden PH increases that kill all aquatic
life in the pond.
Eradicating Trash Fish— Prawn juveniles are only about 1
to 2 inches long when stocked and are extremely vulnerable to
predation by fish. The pesticide rotenone is widely used to eradicate
wild fish before ponds are stocked with prawns. It interferes
with respiration and is toxic to fish at the rate of 1/3 gallon
per acre-foot. It must be given time to break down (about 2 weeks
during warm summer temperatures and longer during cool temperatures)
before prawn juveniles can be stocked. Down (about 2 during warm
summer temperatures and longer during cool temperatures) before
prawn juveniles can be stocked.
Pre-Season Pond Conditioning/Fertilization— Providing a
stable, productive environment in the pond before stocking the
prawn juveniles will help to prevent stressful swings in water
quality factors such as dissolved oxygen (DO2) and low pH. Low
DO2 and high pH not only slows the growth of the prawns but can
cause significant mortalities. Beginning about a week before
stocking, add 250 lbs/ac of alfalfa meal plus 100 lbs/ac of soybean
meal these meals add organic material to the pond which contributes
to stability in water quality. Expect to pay about $7.00 to $7.70
per 50lb bag of alfalfa meal and $5.70 to $6.60 per 50lb bag
of soybean meal. This pre-season fertilization will cost only
about $50 per acre. Fertilizing earlier may lead to the accumulation
of unacceptable numbers of large aquatic insects that could prey
on juvenile prawns.
Dissolved Oxygen— Respiration by prawns requires oxygen
which is acquired from the water by diffusion across the gills.
Prawns became stressed at DO2 levels below 2 mg/L. As a basic
rule, low DO2 concentrations in prawn ponds may be expected to
increase the quantity of organic matter in ponds. This results
in lower DO2 concentrations at the bottom of the pond, as well
as high ammonia and nitrite.
There are many different types of aerators that have been used
in prawn culture. Generally, 1 hp/acre will provide sufficient
aeration at relatively low biomass densities (1,000 lbs/acre),
and low feed inputs (<50lbs/acre/day). However, as production
intensity increases with higher stocking and feeding rates it
may be necessary to increase aeration or have additional emergency
aeration available. The best approach is to have backup aeration
available and to monitor dissolved oxygen levels daily. The best
time to check oxygen is early in the morning (6 am), because
this is generally the lowest reading of the day. Aeration is
needed more at night than in daytime, because photosynthesis
usually maintains high concentrations of oxygen during the day.
However, crustaceans live on the pond bottom, and mechanical
aeration to circulate pond water continually replenishes the
supply of oxygenated water at the pond bottom. Thus, daytime
aeration of heavily stocked prawn ponds is recommended.
pH— Freshwater prawns are relatively sensitive to high pH.
As a general rule, a pH above 9 is a concern and a pH of 10 can
cause prawn mortality especially if it exists for prolonged periods
of time. pH should be monitored once or twice every day. Many
farmers have experienced problems with pH, especially in relatively
new ponds where pH can rise to dangerous levels in the absence
of carbon dioxide, which acts as an acid. New ponds have a limited
source of organic material (the source of CO2), and adding this
organic CO2 source to ponds has been the approach taken to help
reduce the lethal pH spikes. With limited success, sugar has
been recommended for use at 10 lbs/ac/day as a readily available
source of carbon. Application of the sugar should stop when the
pH drops back down to a safe range (below 9). Be aware that large
amounts of sugar might contribute to low DO2 levels. Calcium
sulfate (gypsum) has also been used at 400 lbs/ac with some success.
It should be applied this time of year to allow it time to interact
with the soil.
Ammonia and Nitrite— Ammonia and nitrite are waste products
that come from prawn excretions and decomposed feed. In the early
years of prawn production in Kentucky, stocking and feeding rates
were low enough that these waste products caused no problem.
The new, more aggressive rates now make it necessary for prawn
growers to check ammonia once a week and nitrite twice a week.
(Last year several prawn growers lost entire crops from high
ammonia and nitrite). Chloride ions in salt (sodium chloride)
protect shrimp from high nitrite, so add a 50 lb bag of salt
per acre-foot at the start of the growing season and maintain
this concentration throughout the whole season (adding salt after
significant rain, etc.). A 1 acre pond averaging 4 feet deep
would get 4 50-pound bags of salt. This equals 11 ppm chloride.
More salt may be needed if nitrite levels rise above 3ppm.
Please contact anyone from the KSU Aquaculture Program or from
the UK/KSU Cooperative Extension System (County Agents or Small
Farm Assistants) with questions on prawn farming or other aquaculture
ventures. It would be a good idea to do preseason water quality
testing.
LESSONS FROM A GROWER
By Jane Corwin, Guest Columnist
After attending the Association meeting recently in Mississippi,
I realized that if I had known just how technical prawn growing
could be, I probably would never have tried it. My husband is
a cattle and tobacco farmer and I have been a school teacher
for 26 years. We have a greenhouse operation where we grow bedding
plants and chrysanthemums. Nothing we have done had prepared
us for this venture, but I just felt that it was very exciting
and I wanted to try it. Since this was (and still is) the only
one of its kind in our county, we experience much interest, curiosity,
and skepticism. .
I do feel that it is good to go into a project with no prior
knowledge or experience to rely on. That helps you to study and
follow the guide lines provided by experts in the field. We were
very careful to follow every suggestion completely. I believe
that the proper feeding procedure is vital for a good harvest.
We fed from a boat every day. My husband managed the trolling
motor and I fed from both sides of the boat. We traveled the
perimeter of the pond and then up and down the center every time
we fed. I had the proper weights for every day's feedings marked
on the calendar and weighed the feed at every feeding. Our harvest
resulted in very large (some 18 inch) and very uniform prawns.
We harvested approximately 850 pounds from a one-acre pond.
This was a very rewarding experience, and I am looking forward
to stocking two one-acre ponds this year. I have been contacted
by several people who did not have such good results last year.
In listening to their questions, I feel that a lot of the failures
were due to a lack of dedication to the project. Once I had begun
the project, I think that I felt pressured to prove myself and
to prove that this could be done successfully in our area. I
can only hope that this year's results will be as good.
FRESHWATER PRAWN PRODUCTION IN TENNESSEE
By Professor Thomas K. Hill
www.utextensions.utk.edu
Commercial production of freshwater prawns (shrimp) has been
in the news lately. News media highlighting the prospects of
growing shrimp in ponds in Tennessee is exciting and has produced
a flurry of requests for information on freshwater prawn culture.
Fortunately, some good prawn production information is available
from the University of Tennessee Agricultural Extension Service.
Freshwater prawns have been grown in Tennessee for two years.
The 2001 crop has recently been harvested and as might be expected,
production ranged from about 300 pounds/acre to more than 1000
pounds/acre.
As you make plans and decisions about your involvement with prawn
production next year, we hope the information on our web page
will be beneficial to you. Also, we will try to provide links
with other sources so that you should be able to find answers
to most of your questions. We want to help you be successful.
Mississippi State University will conduct toxicity studies.
Please furnish the Association the name of any chemical you
would like to use for herbicide or algae control. Also, tests
can be conducted on any chemicals used in your growing area that
are applied on adjacent crops that may have harmful effects on
freshwater prawns and shrimp.
Results will be furnished to Association members in future newsletters.
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