Dr. 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?

The industry 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.

They started 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.

The industry 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.

And beginning 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.

The farmers 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.

They're probably 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 fairly accurate.

The channel 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 it cost.

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.

And there's 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 aquaculture.

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 are happening?

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.

The construction 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.

Feed. People 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.

But there's 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.

Usually when 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.

It shouldn't 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 the hatcheries.

The concern 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 shrimp fishery.

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 Aquaculture Alliance?

Anything that's 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 new technology.

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 management practices?

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 system.

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.