Paula Sylvia is a project manager for Hubs Seaworld Research Institute.


Why is Maricultura del Norte a sustainable operation?

In some countries, it can be unsustainable. The tuna aquaculture industry as it is today can be viewed as unsustainable, because the fish that they are using for those farms are a spawning stock and go to those particular areas specifically to spawn. In other countries, that don't have spawning stock going through their areas at the time they catch fish for the farms, it's more sustainable because they’re not catching animals that are going there to spawn. For instance, in the case of the North Pacific stock — the Pacific Blue Fin stock — it's more sustainable than in other places in the world.

What about the ranching operation of Maricultura del Norte?

The good side of it is that it is still a young industry. The good sides are catching a resource, a certain amount of tonnage of a resource, and adding value to that resource in the end. They're not taking more fish out of the ocean for profit. They're taking the same amount of fish and adding value to that population and increasing the tonnage produced. So, in effect, it's not taking any more. It's adding value to an already existing stock that's being exploited anyway. In the case of the West Coast, there are not any quotas for those fish. It's not unsustainable, because they're no quotas set on that fishery right now.

What about those quotas?

I may have misrepresented that. Right now, I don't view it as a problem. There isn't enough exploitation happening there for it to be a problem. However, the boom and bust nature of this particular industry and the profitability of it in the market are forcing a lot of people to come from all over the world to fish that stock that has no quotas. It is going to become more of a problem in the future.

What needs to be in place to protect the stock?

First, what needs to be in place is a comprehensive data collection plan that encompasses the fishery managers, the fishermen themselves, and the aquaculturists that are operating here on this coast. Then, a proper assessment can come from there.

It's sustainable now, but how about the future?

It's sustainable now, but because of the value of this fish, it's attracting a lot of investors worldwide to come and operate on this coast. There is a healthy stock here, because there are no quotas. In the future it will become unsustainable. Not just from the over-exploitation point of view, but also because the industry is still young. It has to mature and go to the next phase of reproducing fish in captivity. That's going to take some time. Until that happens, there is going to be a period of over-exploitation happening there.

Would you like to restate that?

It's sustainable now, but it's not going to stay that way. For this industry to be sustainable, it has to go to the next level of maturity. This is true for any aquaculture industry which is closing the life cycle of the fish.

Can you tell us about Japan?

The breakthrough that Japan has had as far as closing the life cycle of the Blue Fin Tuna is very significant. The industry cannot expand anymore without returning to the next level. They must take the closing of the life cycle and produce hatchings and fingerlings that can be used for stock enhancement or for commercial purposes. It's very important because hatchery development up to this stage has virtually been very difficult. The Japanese have solved a lot of rearing problems that will make it easier for that technology to be transferred to other countries.

Will the hatcheries really have that great of an impact on the stocks?

It's too early for me to tell. I do agree with the common criticism, that it’s hard to really assess if the enhancement is having an effect on fisheries. Blue Fin is a very illusive fish. It would be very difficult to track if that is working, as far as enhancement goes. However, it doesn’t hurt. It can only help, but it’s difficult to assess at this time.

Would rearing hatchling really be viable?

I think raising tuna from an egg to a harvestable size is definitely a viable activity. However, it's the size of the fish that you want to raise that’s questionable. If you raise them to their current market size which is several hundred kilos in some countries; that is not so viable. It would become economically cost prohibitive if you’re trying to feed a fish.

What's more likely to happen is the market will change for this species in the future. There will still be a place for large fish in the marketplace. As this industry grows, as salmon did 20 years ago, it’s going to be a different product that tuna can easily fit into. We can raise a fish to 20 kilos in a year or less or more and that would be a viable option.

Can you talk about feeding the fish in a farmed situation?

There is not as big an impact as the criticism says there is on the forage fish. These animals would be eating forage fish, anyway, in order to grow. There has to be a move within this industry to move from the current frozen fresh fish as a feed item for these tuna to move towards a manufactured feed. For this industry to mature and grow, it has to move into that level. It’s more efficient.

The food conversion ratios would be more efficient on a manufactured feed versus a frozen or fresh product that’s fed to the fish. In order for the industry to grow and move forward, it has to move onto a manifested pellet that will take less from the foraged fishery source. Even though there is foraged fish used for fishmeal. From a farm management point of view, you don’t want to be feeding trash fish to your stock.

From a health management point of view, as far as growth rates and food conversions go, it increases your food conversion ratio, which increases your food costs and then decreases your product. The industry has to move away from that in order for it to mature. It’s going to grow to a point where there’s so much competition that only the people that are utilizing proper farm management techniques, which exist for all other aquaculture species in the world, well, they have to be applied to tuna.

Two things have to happen. Closing the life cycle, i.e. getting this developed manufactured feed that improves the food conversion ratio of the species, and increasing its growth performance. That is happening. It’s being developed now. It’s under research and development phases in other countries. It is coming. So the effect on the wild foraged fish stock should decrease even though some of that fish is used for fishmeal purposes for this manufacturing feed. It has to move in the direction where in order to improve growth performance, and everything else that defines an aquaculture species; it has to be in that direction.

What are you saying about the impact on foraged species?

Farms cannot be relying on the use of foraged fish to feed their animals. Not because it is unsustainable for the foraged fish, but because, for farm management and health management reasons, it’s better. Growth performance and feed conversion ratio reasons make it better to feed your fish a manufactured pellet. It’s not a problem for the foraged fisheries because these animals would be eating those fish anyway to grow in the wild.

What is the conversion ratio for tuna? I've heard 20:1.

It's not 20:1. It's not. I mean you have to spend some time doing the research and collecting the data and exercising proper feeding techniques. These are all the things that all farms do around the world in order to get that data. It’s really 7 or 8 to one, if your feeding husbandry techniques are good and sound. So, a 7 or 8 to one — and that is a wet weight. If you dry that down — having fish being over 70% moisture — if you dried that, it would be close to 2 to 3 to 1 conversion ratio. Which is really good! But you have to practice good husbandry techniques in order to get that. That’s really what it is. In Australia, they’re doing that right now. In other farms that don’t keep track of what they feed or don’t really have a handle on what’s really going on, they’re losing money and they’re losing weight on the fish.

Can you say more about conversion ratios?

The fact is they do have good conversion ratios if you feed them properly and with proper feeding techniques. They do have good conversion ratios. Manufactured feed that is coming in the future will improve the efficiency even more.

Can you address the Blue Fin Tuna aquaculture in the Mediterranean?

There are a lot of unknowns about the industry in the Mediterranean. A lot of people there will tell you that they’re capturing the stock that has already spawned. In some cases that may be true, but certainly all the fish are not spawning at the same time during the time that they’re captured or before or after they’re captured. I personally witnessed several vessels catching fish for farms or not for farms that were not spent. They’re ripe and gamey.

A lot of countries in the Mediterranean don’t necessarily have proper policing that can have an accurate account of what’s going on there. The farming is good. It’s good for the resource. It doesn’t take more out of the ocean than what’s allowed. However, to say that they’re farming a stock that’s already spawned for a season is very inaccurate in some cases. Those fish cannot return the next year to spawn again. They’re taking a variety of size classes that are pooling together to come to spawn or not to spawn within the same schools. It’s a very gray area there.

Why is catching fish, before they spawn, a problem?

The Mediterranean stock of fish has a big debate on whether it’s an eastern or a western stock. The fish that come into the Mediterranean on a yearly basis are going there to spawn. Of that stock that migrates there on a yearly basis, some of those fish don’t spawn because of age or whatever reason which is still unknown.

However, to fish a stock that’s about to spawn, ready to spawn, or that may spawn in that particular season is detrimental to that stock eventually. Either you’re capturing them for a farm and stressing them out so they can’t spawn, or you’re preventing them from spawning in another season that they may return back to the Mediterranean.

Why is the state of the stock even a concern?

It’s of great concern because that is one of only two known spawning grounds for that particular species of tuna. There’s one in the Gulf of Mexico in the United States and the other is in the Mediterranean. To have a fishery as big, or a tuna aquaculture industry as big as it is and growing, there is danger for that particular stock.

What’s your concern about the fish they are catching there?

The concern is there are only two places in the world that have that particular species, which happens to be the most valuable in the marketplace today to spawn. There’s the Gulf of Mexico in the United States and there’s the Mediterranean. With the profitability of this business, the farming situation is growing over there. There are a lot of countries that circle the Mediterranean with this fish. In areas where the fish spawn, expecting an increase in the farming activities or any fishing activities, there is danger for that particular stock.

Could you restate your experience with fish in the Mediterranean that have not spawned yet?

I do have personal experience from working on purse seining boats in the Mediterranean that were catching fish both for the farms and fresh for the market. Those fish had not spawned before they were captured. In an expanding aquaculture industry or fishery, there is danger for that particular stock if you’re catching them before they’re spawned. This is what is happening much more than what is being stated.

What do you like about tuna?

Ever since I first started working with them, I just had a passion to work with these fish. They’re an awesome fish. They grow fast and they taste awesome. They’re an amazing fish that’s still very illusive and not really that much is know about them. They’re fascinating to me because I want to know as much as I can.

Should this fish be saved for future generations?

This fish should be around for the future. All fish should be around for future generations. But tuna, in particular blue fin, are an amazing animal. Nobody should be denied access to that animal.

Please comment on the state of the industry right now.

Currently, the way the industry is today, it’s not really true fish farming. It’s feed lotting or ranching. However, the industry is moving in a direction to domesticate the species. The industry has to move into the future and is moving into the future to become a more domesticated species. Closing the lifecycle and work on closing the lifecycle is already happening in other countries. That technology will be transferred and utilized to make the new chicken or beef of the marketplace.

How about another ending?

It’s moving and maturing into the future, as a domesticated industry that will supply much needed valuable protein to a growing world population.

What are the implications of the state of fish stocks in general to tuna?

It will definitely affect the expansion of the tuna industry, whether it’s from commercial fishing or farming operations. It’s bad for everything. It only serves to support the impetus that is needed to move an aquaculture, or any pelagic fish species, to the next level. Research is needed on closing the life cycles in order to provide fish for stock enhancement or farming operations.

Other comments?

Our research institute does a White Sea Bass stock enhancement program, which is really successful. We see how hard that is to track if that is a success or not.