TRANSCRIPT - Claude E. Boyd
Claude E. Boyd is a professor in the Department of Fisheries
and Allied Aquacultures at Auburn University, Alabama.
Now that aquaculture is growing so fast, what are the current trends
in shrimp aquaculture?
As you study
the oceans' fisheries, it's somewhat reached an equilibrium and
the demand is still increasing. And demand can only be met through
aquaculture. There is no other way. There's no good way that anybody
knows of right now to increase productivity of the ocean. There's
talk about fertilizing the ocean and all this, but nobody knows
definitely what'll work.
So at least
as far as what we know now, aquaculture is the only way of increasing
the fisheries' production. And there are even projections that aquaculture
can't really produce enough to keep up with the demand if the world
population increase continues at the same rate.
From a business
standpoint that's quite good because if there is a demand for the
product and somewhat of a shortage, so you should be able to get
a decent price for what you produce. In shrimp farming, it's reached
a stage now where about 25% of the shrimp placed on the world market
are produced in ponds.
What kind of changes is the industry going through?
is new, so to speak. There's been some shrimp farming for a long
time, but it was quite extensive and they would just build some
ponds and basically pump the water in, and the sea would come in
with it. But then beginning about 20 years ago, they began do shrimp
farming on a more organized schedule.
building to produce small shrimp in the hatcheries, they built the
ponds in a standard construction practices, and began to stock them
and use feed to increase the production above what you can get by
the use of fertilizers or just the natural productivity of the water.
And then of
course they incorporated mechanical aeration into it to provide
even greater production with the feed than it can just be achieved
with the natural sources of oxygen. And they developed some better
technology for managing the whole industry - not only the ponds,
but better processing and better feed manufacturing.
has become much more sophisticated but I think the big steps were
made in developing the feeds that allowed much more production,
and then the use of aeration. But of course aeration isn't used
all over the world. It's used mainly in Southeast Asia in the shrimp
farming. And a little bit in Australia and US for their shrimp farming.
Generally in Latin America they are not at that stage, but they
are at the feeding stage.
Everyone we've spoken to has said how the industry is aware of the
problems and how there is a lot of work going on research and implementation
on correcting those problems.
About 4 or 5
years ago this became popular in the publicity standpoint of shrimp
farming, but the industry had already started improving their practices
before the environmental issues were raised. And the main reason
for this had to do with diseases, because shrimp apparently do not
have a good an immune system as fish and other vertebrates. And
so they are susceptible to some of these epidemic diseases, particularly
some viral diseases.
around in the mid-80's there were some fairly severe epidemics in
different countries. The first one that was really hit big with
this was Taiwan back in the late '80s. And then there have been
a number of other disease problems since that time.
realized pretty quickly that one way of reducing these diseases
was trying to get animals that weren't diseased to start with -
good post-larvae - for stocking the ponds. And they began ways of
getting better animals for stocking. And then another thing that
they quickly discovered is that in shrimp farming you're discharging
water out into the coastal area, and of course you're using water
from the coastal area so anything that you release from your farm
it could come back to you or it could go to somebody else.
So if there
are either pathogens or carriers of the pathogens in that water
and you bring it into your pond you can obviously cause yourself
a problem with diseases. This is when they started reducing this
water exchange to try to prevent the disease. And it was one of
the things that they found was effective.
In fact, people
found out pretty quickly that the farms that had the most problems
with the diseases were the ones that had shared intake and discharge
canals of their own farm or were sharing these with other farms.
One of the ways
of treating waste, like municipal waste, is you can put it into
a sewage oxidation pond and hold it there. A lot of cities have
more rapid ways of doing this but for small communities, a lot of
times they use those sewage oxidation ponds where they just put
the water in and have a certain detention time and the natural processes
purify the water.
A pond is a
lot like that. If you put the water in there, it's purified by the
natural processes. So by reducing the water exchange you've retained
the water in the pond longer and there's more opportunity for these
natural processes to improve the quality of the water before it's
discharged. The other thing that was quickly noticed was that the
animals that are stressed are much more susceptible to diseases
than those that are not stressed. So they found that by maintaining
better water quality in the ponds they had less disease.
So this brought
about some moderation in the stocking rate because some farmers
had gone to quite high stocking rates to try to get as much production
as they could. And as you put more feed in, you get more waste.
You can't convert that feed 100% to shrimp, so the waste would increase.
And so by moderating these stocking rates and trying to maintain
better water quality, they had shrimp that was less stressed, so
there was less problems with the disease.
I think you
can see this in several countries. If you could go back and look
at what they were doing ten years ago and what they're doing today,
you'll find that they're using better feed. It's more stable and
doesn't break up into the water as quickly, so the shrimp has more
opportunity to eat it.
stocking at somewhat lower rate than they once were. They're using
the feed in a more conservative manner to try to insure that it
all gets into the shrimp, and they reduced the water exchange. And
they generally improved all their management practices.
And not only
does this benefit the environment but it also comes back to benefit
the farmer, and improves his efficiency. And, of course, sometimes
implementing these better practices costs a little bit of money
up front, but in the long run it probably improves the profits and
it certainly makes the prospects for sustainability much better.
We've also heard a little about cutting down on content of fishmeal
and making it more vegetarian-based. Is there an advantage there
in elimination of waste product?
Well, not only
in eliminating the waste but also in reducing the cost of fishmeal;
it's expensive. The best example I can give you some is catfish
farming. I'm not saying the exact same thing can happen in shrimp
farming, but I anticipate something similar to this will happen.
I'm not a nutritionist. As I've said I'm more in the water and salt
quality business, but I think the numbers that I'm giving you are
catfish farming business in the US back in 1972 or 3, the feed was
costing around $365 a ton and it contained around 42% protein and
I think it probably had over 10% fish meal in it. And over the years,
through research they've reduced the fishmeal content of that feed
by supplementing it primarily with soybean meal. And now the feed
is 28-30% protein and I don't think it has over 1© - 2% fishmeal
in it. And I'm not sure today what it costs, but somewhere in the
neighborhood of $260 or 70 a ton, which is actually less than what
So that's an
example of what can be done, and I'm sure as they learn more about
shrimp nutrition they will be able to reduce the fishmeal and fish
oil component of it and replace it with vegetable proteins. And
this will reduce, not only the protein content of it and conserve
fish meal, which there is a finite supply of, it'll also reduce
the cost of the feed.
Can you speak about the use of antibiotics?
I guess we can
say it's an antibiotic issue but it's generally taken up as a chemical
issue - the chemicals that are used in aquaculture. And in our culture
we use quite a lot of chemicals and chemicals are definitely a good
thing. I don't think anyone can deny that chemicals are not good.
I'm not saying we can do everything with chemicals, but there are
proper use of chemicals and there are improper use of chemicals.
And I think
in aquaculture, and in shrimp farming in particular, people have
taken this chemical issue and antibiotics issue and just say it's
bad. Well, that's not really true. What's probably better is to
approach it as such is done in the US in aquaculture. And here we
have certain antibiotics and drugs that can be used for disease
treatment that are approved for years.
And not only
the compounds are approved but the way it's used is approved, and
they specify how much you can treat with and the withdrawal times
and so forth. So I think what really needs to be done in the shrimp
farming is not that anybody needs to ban the use of chemicals -
antibiotics and drugs - what they need to do is to come up with
some approved lists and approved legal management practices.
There's a seafood
inspection program in place now for stuff imported into the US.
Europe has a system and I'm sure Japan has one, too, and they examine
the product coming in for residues of certain compounds and if you've
got the residues, you've got a problem.
So it's to the
shrimp farms' advantage to follow the rules of these compounds.
The main thing is you don't want to use these compounds just as
a general treatment. Just like taking an antibiotic everyday to
protect your health, I don't think it'd be very good in the long
run because bacteria will become resistant to the antibiotics and
then they won't be very useful.
a danger there if you use too many of them. Eventually they may
lose effectiveness. Or they could have some adverse effects on the
environment outside of the pond if they are released before they
degrade in the pond. So there needs to be restrictions on the uses
of these materials, but people should be allowed to use them where
they really need, I think. And this information is generally known.
There's quite a lot of information on the use of antibiotics in
The protocol with antibiotics and with water exchange, or any of
these techniques that are being developed or are already being implemented,
for example in Honduras - how will this information get across to
these developing countries where the bulk of aquaculture operations
In Latin America,
an awful lot of shrimp farm operators are university trained, and
a quite a number of them were trained in the US or Europe. There's
been a lot of use of consultants in Latin America. They bring in
consultants that know about different aquaculture practices and
adapt in that manner.
Of course now,
the governments in some of those countries are developing some research
programs and extension programs and so forth. But shrimp farming
in general, the people have just gone out and adapted things from
other kinds of aquaculture or brought in people that had the know-how.
As I mentioned
to you earlier, shrimp farming is not particularly high-take. It
involves certain practices such as: you to have a way to put water
in it and drain water out; you have to be able to regulate the natural
productivity of the pond by possibly adjusting the pH through the
use of limestone; or in some cases they may use some fertilizer
or nutrients to stimulate the desirable plants in the system; the
use of feed; and where they have a high enough stocking and feeding
rate, the use of mechanical aeration.
techniques of building ponds are pretty well known. We've built
a lot of ponds over the years and building a shrimp pond is not
much different from building any other kind of pond. The technology
for building an embankment or putting in a water control gate, that's
nothing new that has to be developed specifically for shrimp farming.
An engineer knows how to do that. So that information is available.
know how to make pelleted feed. You may have to adjust it a bit
for the shrimp, so it's the right composition. And of course they're
learning more about the nutrient requirements of shrimp and the
feed is changing. And they get better material for binding the pellets
together so that it doesn't break down too quickly in the water,
and this is one of the problems with shrimp. The fish would tend
to grab the pellet and gulp the whole thing, but shrimp's a nibbler
so the feed deteriorates quickly and the shrimp doesn't get it all
and what's left over pollutes the water.
But when you
get into something like aeration, aeration was originally developed
for wastewater treatment industry but modifications of those aerators
are used in the aquaculture industry. So this technology is all
available. And much of it can just be purchased if you know water.
But the shrimp
farmers in general have adapted things from other areas agriculture.
And a lot of their knowledge has simply come from other areas of
aquaculture, because there's a lot of pond aquaculture in the world
now. There's a lot of research done on them and some of it has been
developed specifically for shrimp farming.
been a lot of adoption and modification to make it work, but basically,
whether you're growing channel catfish in Mississippi or shrimp
in Thailand, the basic procedures you go through are about the same.
There are some differences in how you handle the animal and how
you market the differences in composition and feed and so forth,
but the basic principals are all the same.
There's been a movement in Thailand to move the ponds inland. Do
you see that as a viable direction?
That's a practice,
which I don't think is extremely extensive. I don't know the consequences
of this. There's some problems with it. You can bring in saltwater
and possibly cause some salinization problems, but I guess what
saves you is that it's too extensive to bring all that saltwater
in there. They're just going to bring in the minimum amount.
people think about growing shrimp, they think about the ocean water,
but the shrimp in ponds can do quite well in water that's only 2:1000
salinity. Ocean water is about 35:1000 salinity. But if you've got
one, or two, or three or four parts to a thousandth salinity, they
can do quite well. So they're not growing them in 35:1000 salinity
water. That would be far too expensive. So it's not quite as bad
as it sounds.
I don't really
know about the sustainability of this kind of industry in the long
run, if it's always going to be profitable to have that water in.
It's an expensive thing. I haven't heard of any problems resulting
from it, but I think it could be done if you took all of the proper
precautions - prevent the downward seepage of saltwater into this
fresh water aquifer and don't release the water.
And of course
you're not going to be using water exchange here because that means
it'd be letting the salt out and it would be that much more expensive
to let it in. And so just by the expense of the salt that they're
using provides some sort of environmental protection, for sure.
I don't anticipate that ever being a mainstream shrimp production
procedure, but it has been done.
I didn't know to what degree this is happening, but someone else
was saying that yes, they're trucking all the ponds inland.
It can be done.
I just don't know how they'll do in the long run. They might work
out the technology and be able to do this on a bigger scale, but
right now it's a very small amount of shrimp that they've produced
that way. I don't think that some people might be worried this might
result in a lot of salinization of inland water supplies.
What is the practical solution for discharging effluence, whether
it be on the coast or inland?
Well, just pumping
the water through the pond doesn't really cause any particular problem.
The problems result from the nutrients and the solids that maybe
suspended in the water. The nutrients come from the feed and they're
either dissolved or contained in the plankton that's in the water,
or you can have some suspended salt particles in the water.
But the main
thing that should be done is they need to reduce the water exchange
as much as possible. And when you do release water, it'll be diluted
and taken away from the immediate vicinity, and the ecosystem can
assimilate, as long as you don't overburden the assimilation capacity
of the ecosystem.
A lot of the
sediment that comes from aquaculture comes from erosion during the
time they're draining the ponds or from erosion in canals and so
forth. So just by taking the proper precautions in the construction
of canals and the discharge of water they can do a lot to reduce
the solids loads. And a lot of the phosphorous is associated with
the solids, so if you reduce the solids you'll take much of the
phosphorous out of the water.
You can also
put in a sediment basin and move solids at the end of the process
before your final discharge. In some cases it may not be necessary,
but if you do have effluent that still has quite a bit of solids
in it, a sediment pond can be quite effective. In Thailand they
have a shrimp farm and one of the requirements of the law they passed
there is that they have to devote a certain percentage of the farm
to a sedimentation pond.
What percentage do you think they actually do?
It was either
10 or 15% of the pond area that had to be devoted to sedimentation.
What's your sense of how many farms actually have sediment ponds?
This law applies
to the farms above about 50 rai - around 6 or 7 hectares, I believe.
The farms bigger than that all have them, I think. And awful lot
of smaller farms have those sediment ponds.
A Thai professor in Songkhla said if everyone puts in those sediment
ponds, that's going to raise their price of shrimp, yet the world
wants inexpensive shrimp. The world has to decide which it prefers.
be that expensive to make sediment ponds. I'm not trying to say
all the farms in Thailand have sediment ponds, but a lot of them
do, especially the bigger ones. And by bigger, I mean a few hectares.
How about the problem with wild-caught larvae, which I understand
is more of a problem in Latin America? I heard that most of the
post-larvae used in Southeast Asia comes from hatcheries?
They have to
have a larva to stock in their pond. But this is one place where
the shrimp industry is really going to change in the future. Because
right now they just catch the brood stock from the sea and they
bring them in and they spawn them in the hatchery and they produce
the hatchery of post larvae. Or the other thing they do is, they
go out and they get the wild-caught larvae, which then spawn.
This is a problem
in the industry because it depends on the wild stock for stocking
aquaculture ponds. So the shrimp industry will, in the future, produce
its own brood stock. And they won't even be dependent on the sea
for their brood stock at some point.
But right now
most of the brood stocks do come from the sea and in certain parts
of the world they tend to use those wild-caught post-larvae because
some of the farmers think they may be stronger than the ones in
comes in when they use some kind of small-mesh seine and they catch
tremendous numbers of post-larvae, and there's some bycatch of fish
when they do it. And some people think they're taking tremendous
amounts of small shrimp from coastal waters to put in these ponds
and that's obviously going to have an adverse impact on the natural
But when you
really think about it, these shrimp produce just huge numbers of
young and very few of them survive to be adults anyway; most of
them die off. So even though there are a lot of animals being caught,
they're probably not as dramatic a thing on the ecosystem as people
think. It's more of a perceived problem.
But the shrimp
industry needs to go towards the hatchery-produced post-larvae and
the farm-produced brood stock eventually. That's the direction they're
going anyway. So I think this is going to end up a non-issue in
a few years.
As to what damage
using the wild-caught larvae has done, I don't think anybody can
give you real convincing evidence that it has caused a problem.
Likewise it'd be difficult to show that it has not caused a problem.
But it is an issue that I think you'll see become less and less
important to the farmer. They'll rely more on the hatchery for post-larvae
in the future because it's a more controllable system.
What is the difference between brood stock and larvae?
The brood stock
would be the shrimp that they get the eggs from. Then they take
the eggs and produce the small post-larvae. And then they take the
post-larvae into the pond and grow them up into the larger shrimp
that's sold in the market.
What criteria do you think are the important ones for the Global
going to survive and prosper, society is going to have to go through
some changes, and the shrimp farming industry is definitely changing.
They're coming up with better procedures and newer procedures and
But not only
has organizations like the Food and Agriculture organizations of
the United Nations developed Codes of Conduct for aquaculture, but
some of the national shrimp farmers' associations are developing
these practices. The shrimp industry got together and some groups
and members got together and formed the Global Aquaculture Alliance,
which is dedicated towards improving shrimp farming practices.
And so they're
coming up with these practices. It's popular to call them best management
practices, but sometimes they may not be the best; they may be improved
over time, so you ought to call them good management practices,
or better management practices.
Codes of Practice
- they're going to have the farmers try to adopt them and I think
they will. I know some people may say, well, you know they can say
they're using these practices and they have to be regulated from
some outside agency. But what you have to understand is that in
a lot of these countries where shrimp are farmed, there's not a
real good system of pollution control and so forth in place. They
may have some regulations, but not a lot.
In the United
States, Codes of Practice have limited value because we have state
and federal agencies that regulate water pollution and other aspects
of the environment. So I think what these Codes of Practice do is
provide some kind of protection until these governments actually
develop a system of regulating various industries in their own country.
Since a lot of these shrimp producing countries do not have regulations
yet, or they don't have the resources to enforce them, would being
able to command higher prices for a high-quality certified product
be a positive reinforcement for the farmers to adopt these best
I think there's
some possibility to this. But there does have to be some way to
ensure that the shrimp sold under this certification were actually
produced using whatever methods that were specified in the certification
I think it's
going to be a long time before we get to this. I think what's probably
more likely is people will make labels and these labels will say
that the shrimp were being produced under these codes of practice
and then you more or less have to take their word for it. But I
think sometime in the future certification is definitely something
we will probably see. We're already seeing this with wood products
and certain other products.
On the other
hand, I feel like the only way you can ever solve a problem is to
solve it kind of at the grassroots level, by teaching these farmers
how to do things better. Not just aquaculture but in anything, people
doing the work have to be taught to do it better and learn the reasons
for doing it better. And until you do that I don't think any kind
of system or regulation is going to work because you come up with
some kind of regulatory system, people are always going to find
a way around it if they don't think it's necessary. So I guess I
have more trust in people than a lot of the environmental activists.
And again, they'll
say, you see what's happening to the world. And I'd like to say
again that our big problem is not that people are going out and
destroying the environment through negligence and not caring and
whatever. It has more to do with the fact that there are too many
people and maybe they just don't understand what they're doing all
the time. So I think regulations are good and all that, but I think
you need to understand why you are obeying the regulations or you're
not going to really do it properly.