| INTERVIEW
TRANSCRIPTS - Dr. Steven Berkeley
Well there’s what we call sexual dichotomy. The males and females grow at different rates, mature at different ages. The females are the component of the population that we’re most concerned about because they are the fish that do the reproduction. The minimum age for female swordfish to spawn is about age five. And about 165 pounds. And most of the population now, of course, is below that size. So it’s true. For most fish that are being caught now, for most of the females anyway, they have not reproduced. Males mature at a much younger age and a smaller size. And so that’s probably not true of the males. But again, it’s the females that are the most vulnerable.
I don’t know the exact number but the percentage of females that are being caught now by long-lines that are below the size of maturity is at least 50%, and probably more than that.
Well it’s a much more complex question than that because it’s not just what size you’re harvesting; it’s the rate at which you’re harvesting the fish. It’s the proportion of all the age classes that you’re harvesting. The way the fishery is pursued right now, and with long-lines that take all sizes of fish, to reduce it so that the population was sustainable, considering the size classes that are being caught by the gear, would require a reduction of close to half, I believe. It is quite significant though. The landings, I think in the North Atlantic were something like 16,000 metric tons last year. And the sustainable would be less than 10,000 tons. So we’re talking about a substantial reduction in landings. And that still would just stabilize the population, it wouldn’t allow the stock to rebuild. So if you want to rebuild the stock, the quota would have to be less than 10,000 metric tons. The current harvest levels, ocean-wide is about 16,000 metric tons.
Yes, that’s the North Atlantic. And so that includes other fisheries — Spain and Portugal and a lot of other countries.
Because the stock is over fished, there are certain age classes that are particularly vulnerable and require particular protection. And right now, of course, they are the older females which have been reduced so badly in numbers over the last few years. At this point, it’s a different question than it would have been 10 years ago. Ten years ago we were trying primarily to protect young fish because the fish are small. They don’t have a lot of value and they would be much more valuable, both to the stock and to the fishery if they were allowed to grow into larger fish. They grow very quickly when they’re young fish. So it just makes biological sense and it makes economic sense to protect those fish. So protecting those nursery areas, at that time, was the principal objective. Now, because the stock is so badly over fished, you really want to reduce fishing mortality on both old spawning fish as well as young fish to allow the population to recover. So now you really need to protect both the nursery areas as well as reduce fishing mortality, on the older, mature fish population. So it’s not really a simple question. It still makes perfect biological and economic sense to protect the nursery areas. Those fish are young, they’re small, they haven’t reproduced and they don’t contribute economically a great deal to the fishery but they potentially can contribute a great deal to the rebuilding of the resource. Those areas should definitely be protected.
No. There’s almost no protection for the nursery areas. And the only protection right now are essentially quotas. Size limits. I just ran an analysis of the impact of the size limit, and it turns out that size limits are counter-productive in this fishery because such a high proportion of fish caught on long-lines are dead. So that if you have a minimum size, which is one of the regulations that’s in effect now, you end up just throwing back dead fish and replacing them with other fish which actually increases mortality. The size limit is not effective in this fishery. The quotas are potentially effective but they’re not low enough. The quotas are too high to allow this stock to recover.
Well they’ve been diminishing pretty steadily since the 1970’s. And probably before that. Long-lining was introduced in the early 1960’s and before that it was a harpoon fishery. And the harpoon fishery took only large fish, mostly mature fish, fish that had spawned, and so it was a very selective type of fishing gear. It didn’t have by-catch and it took only large mature fish. So it was actually a very nice fishery. Long-lines catch everything; all size classes. They’re very effective. And the populations have been in decline, pretty steadily since at least the late 1970's, early 1980's, with the big expansion of the fishery into tropical waters, as long-lining became more widespread. And the populations have been in pretty much mono-tonic decline since about 1980. So, for almost 20 years now.
Since about 1990 to about 1996, the latest assessments of the North Atlantic show that the population is at 50%, 58% of the level that would produce the maximum yield.
I guess it depends on your definition of "plenty of swordfish". There are swordfish out there for sure. And there’s still significant quantities of swordfish being landed. But the population is declining. The population cannot sustain these levels of harvest. If the population is going to continue to decline, if harvests are continued at this rate, I’d have to ask the question, "Compared to what?". Most of these fisherman weren’t fishing when the populations were at their unfished levels or anywhere near unfished levels. The population of swordfish has been fished since the late 1800s and has been declining severely since about 1980. So there are now plenty of swordfish in the ocean, in the North Atlantic anyway, compared to the level of 1980. There may be plenty of swordfish compared to last year, or almost as many swordfish as last year. But it depends on how long a history you look back on. The population is much smaller than it used to be and it’s smaller in terms of the average size of the fish in the population as well. The average sized swordfish today is less than half the average size it was 20 years ago.
Right, a person’s perspective on whether or not there are a lot a fish or not depends on how far back in the fishery he goes. So if you’ve only been fishing for five or ten years, you don’t see the decline that you would have seen had you been fishing for 20 years.
The reason swordfish are considered over fished is because the population is not large enough to reproduce at the level that it could reproduce at if it were allowed to rebuild to a higher level. Every population of fish has a carrying capacity. The ocean has a certain carrying capacity and there is a level of population that will produce the maximum yield. And that’s the level we are trying to attain, at least with swordfish. With other fish we’re even more cautious. In fact some species were much more cautious than just finding the level that produces the maximum yield because that doesn’t necessarily give you the most protection from resource collapse. But with swordfish, we’d be happy to bring them back to the biomass level, the quantity of fish in the ocean that would allow the maximum production. And as I said before, we’re at about 58% of that level now.
Well, ICCAT’s track record is not very good. Most of the species that are under the jurisdiction of ICCAT are over fished. Swordfish, of course, being one of the primary ones as swordfish is perhaps declining faster than almost any other of the large pelagic fish in the North Atlantic. It’s very difficult to manage a resource internationally. But it’s my sense that it’s only been in very recent years, with a lot of public pressure on ICCAT, that they’ve taken their job at all seriously. Right now the quotas, the management measures that ICCAT has put in place are still too little. They’re just insufficient to allow stocks to rebuild. And that doesn’t seem to have changed in the last few years. They put on quotas. They’ve initiated quotas but not enforced them. And they have size limits that are not enforced and the quotas are too high anyway. It’s a political process. It’s kind of like making sausage; it’s not very pretty and usually the compromises that are reached are not in favor of the resource, but are more in favor of the countries that are exploiting these resources. So what we end up with is a situation where you have quotas that are too high and then the next time the stocks continue to decline and the quotas have to be reduced even further. And you end up trying to chase something and never catching it.
Well my opinion on this is either you count the discards against the quota or you eliminate the minimum size so that you basically eliminate the discards. Either one would have the same effect because you’re fishing under a quota. When the quota is taken, the fishery presumably will be closed. It would actually be far better to count the discards against the quota and if the alternative isn’t an option, because the US has to fish under ICCAT regulations, they can’t just disregard ICCAT—the ICCAT minimum size. But I have been requesting that they go to ICCAT and just try to get the quota dropped because the fish are going to be dead anyway, and there’s no sense dropping them over the side. Such a high percentage of these fish are dead when they’re brought along side a long-line boat. You may as well let the fisherman keep them, count them against the quota and close the fishery when the quota is taken.
The minimum size, as I said, isn’t particularly effective. The only way a minimum size in this fishery can work is if it’s high enough to discourage fisherman from fishing in the first place. Otherwise it’s just going to create a discard, a dead discard problem. So I’m not an advocate of minimum sizes. But if you were to find a minimum...to choose a minimum size that would be effective, it would have to be way larger than it is now. Something around 150 pounds would probably be an effective minimum size because the population is so skewed towards small fish, that a minimum size of something like 150 pounds would mean boats just simply couldn’t fish. And so it’s a de facto closure, it’s not really a minimum size that’s effective, it just forces boats to stop fishing. If you’re going to do that you may as well just have a closure directly and not try to do it through the back door.
The first thing, and the most pressing issue right now is to reduce fishing mortality, which means reducing the quotas dramatically. And that would be a shared reduction by all the countries that harvest the resource, both ICCAT signatory nations and non-signatory nations to ICCAT. Because there’s no sense in having a quota that applies only to part of the fleet. Everybody that fishes for this resource has to reduce the landing, their catch. And it has to be a pretty dramatic reduction for this population to rebuild. So that would be the very minimum step to begin the stock on a rebuilding path. The next step in rational management would be to reduce the harvest of small fish which are very fast growing. The national mortality rate is relatively low. The young fish are putting on weight very quickly. The biomass of that segment of the population is increasing very quickly. So it makes no sense to catch those fish. Because you can’t do it with a minimum size and have a long-line fishery. At least so far we don’t know how to selectively fish only for large fish. What you would have to do then is close the major nursery areas. And we do know where these areas are, or at least we know where some of them are. The Gulf of Mexico is very significant proportion of the catch, very young fish in the Gulf of Mexico. The Straits of Florida has a very high proportion of very young fish. So those areas certainly could be closed to long-line. The Gulf of Guinea, on the other side of the ocean has a very high proportion of very small fish in the catch; close that area. Allow those fish to grow to reach maturity, or at the very least to reach a size at which they’re of higher value — both to the economics of the fishery as well as to the stock itself, and harvest them at that time. And the combination of reducing the quota and protecting the nursery areas will rebuild the stock. And it will not only rebuild the stock to previous levels, it will allow the stock, the production of the stock to increase. Because you can be harvesting fish at a biologically better size, when they’re larger. And so you can actually get more biomass out of the stock by reducing the harvest of small fish.
The data that I’ve seen suggests to me that nobody is doing that — that people are fishing wherever they can catch fish. And if that means going into nursery areas to catch a few big fish and discard a lot of small fish then that’s what they’re doing. Of course, if there are areas where there’s a higher concentration of large fish, naturally they will go there. But the data doesn’t suggest that there’s been any major reduction in the actual catch of small fish, even with the quotas being in place. There’s been maybe a small reduction but not much of one. And so you’ve changed, you’ve converted small fish catches into small fish discards. And that’s been the major impact of this. The foreign fleets have shown very little inclination; in fact, no real inclination to even recognize that there is a minimum-sized regulation in place. They continue to catch small fish, well in excess of the allowable, incidental take that ICCAT allows, which is 15% of the line to catch. Most of the other countries have completely disregarded this regulation. The U.S. hasn’t but unfortunately even though the U.S. fisherman are law abiding, it hasn’t helped the stock because they’re just discarding dead fish.
In the Atlantic gillnetting is very, very small. In the U.S. we don’t allow gill-netting for swordfish; that gear was outlawed a couple of years ago. So that fishery is dead now. And it never was much of a take. So the harvest of swordfish in the Atlantic is by long-line, that’s where it comes from. There’s a very, very small take by harpoon. It’s quite small, almost zero in the US, a little bit in Canada. And there’s just a little bit of incidental gillnetting in Europe. It’s a long-line fishery.
I don’t know if it is politically or practically possible to go back to harpooning. As you probably know, it’s mostly large fish that are seen finning. And right now, there are very few of those fish left in the population. But if you could rebuild a stock to the levels that used to exist, where there was a healthy population of large fish and only allowed harpooning, I don’t think you’d ever need another regulation. You could let that fishery go, unregulated, and the stock would be sustainable.
This is something that I’ve worried about and thought about a lot. And the answer is we just simply don’t know. That open ocean environment is so alien and so remote from human interaction that we really don’t have much appreciation for what these types of impacts of removing these large predators will have on that ecosystem because we have such a poor understanding of that ecosystem in the first place. Falling back on first principles, I would have to conclude that removing all of these large predators in such significant numbers — bluefin tuna and mako sharks and poor beagle sharks and swordfish and yellowfin tuna and bigeye tuna. All of these fish, including the marlins have been severely reduced in population size and all of these fish are top apex predators in that oceanic environment. I have to assume, just based on first principles, that there is going to be a cascading effect of some sort from their removal on the species at lower trophic levels, the lower levels on the food chain. But what those impacts are, we don’t know. It’s a kind of a gamble that we’re taking by doing this, by removing so many large predators from a system that we don’t understand.
Well swordfishing is expanding in the Pacific and I think if you look at the history of fisheries worldwide, pretty much everything that’s happened in the Atlantic eventually repeats itself in the Pacific. And I think there is an opportunity to learn from past mistakes and try to gain an understanding from our experiences in the Atlantic and apply them to the Pacific. So the stocks in the Pacific are still probably healthy. But they’re heavily fished. So I think there’s time to take heed of this and to start implementing management measures. But unfortunately, in the Pacific we don’t even have a management body formed yet. There are some efforts in that direction right now, and probably there will be in the next few years. But right now, we don’t even have a mechanism to implement regulations or even to collect data on a base and scale, like we have in the Atlantic. So, although ICCAT has failed in their management regimes, they have been largely unsuccessful in protecting the stocks. At least we have a very robust data base in the Atlantic and probably quite good stock assessments because of that. In the Pacific we’re not at that point yet. We don’t have the data base because we don’t have that international body collecting the data.
Swordfish are a really amazing animal. They are probably the most widely distributed large predatory fish in the world. They’re found in the Atlantic. They’re found from almost 50 degrees north latitude to 45 or 50 south latitude. They’re found in all the oceans of the world. They’re very large; they’re very powerful swimmers. They have a unique physiological adaptation, which allows them to have this huge range. They have a specialized organ in their skull that heats the brain. It’s a specialized musculature that, instead of using it to produce motion, it uses to produce heat. And it allows them to feel, to exploit both the very deep ocean, which is too cold for most cold blooded animals to exploit. And also to exploit a very large latitudinal range from, like I said, from 50 degrees north to 50 degrees south. So they’re unique in that sense. They grow to very large sizes. They can feed on the bottom, they can feed on the surface. They eat bottom fish, they eat shrimp. They’re a very adaptable predator. Their downfall, of course, is that they have a big appetite and they bite on long-lines very readily and so they’re caught very quickly. They’re very vulnerable to this type of fishing. Of the billfishes, they’re the only bill fish that has that type of bill and it’s a very large weapon compared to a marlin or sailfish, which is relatively small and round. The bill of a swordfish is about a third of their body length and it’s sharpened on the edges — it’s flat and it’s compressed. And the edges are extremely sharp. And they use this for slashing through their prey. You frequently find squid in their stomachs with no heads on them and with cuts in the body, presumably from the slashing action. So they’re different, very different, from the other bill fishes. They’re quite a magnificent species that used to commonly get up to five and six-hundred pounds, even up to a thousand pounds, but that size fish now, unfortunately, is quite rare—almost unheard of.
We don’t know the maximum depth. In the depths that we know they go to, I believe there have been a couple that have gotten hung up on the transatlantic cable—the telephone cables. So we know that they go down. I think it’s about 3,000 feet. They may go much deeper than that; we don’t know. They occasionally show up, actually, in the stomachs of sperm whales. They’ve been known to be preyed on by sperm whales. And they do make very deep feeding forays down, probably to the bottom or near the bottom. They’ve been seen in deep diving submersibles, sitting on the bottom, just almost motionless on the bottom. So that’s unusual behavior for an open ocean pelagic fish. You wouldn’t catch a blue fin tuna doing that or a marlin doing that. So they’re very different than those fish. The theory anyway is that after making these deep feeding dives they will come up and sit on the surface, in the warmer surface waters to allow them to digest their food. All the biological processes slow down dramatically in cold temperatures so being a cold-blooded animal they will sit on the surface. And they probably are a little bit drowsy after that and that is probably why swordfish harpooners were able to approach them so closely. Although I guess after being harpooned they’re active after that. I don’t think they stay drowsy too long. But that is the thought right now, is that it’s a physiological adaptation to allow them to digest their food so they can go back down and have another go ahead.
Well that’s fishermen’s optimism for you, of course. The size of the fish stock just determines to a certain extent the distribution of the fish stock. When a population is at a high level of abundance then all the areas that are capable of supporting these fish will be occupied with swordfish. When the population is at a low level or any population of fish is at a low level, the populations tend to shrink back into the core areas — their most preferred habitats. And there are lots of areas now, especially the near shore areas that haven’t seen swordfish in many decades. And it’s not just because the world has changed or the ocean has changed, it’s because the population is at a lower level and those fish are not there. That’s why there is no harpoon fishery now. There are no large fish. They used to site swordfish from the beaches on Long Island and New England. The groundfish boats would carry harpoons to harpoon swordfish. Well they’re not in those areas now. It’s not because they’ve changed their migration, it’s because the population has shrunk and they don’t occupy those areas anymore. They occupy the more productive core areas where swordfish are found, and that’s why they’re not there. It’s certainly true that swordfish move around. They’re a highly migratory species; they move over broad areas. But these areas are now quite well known. We know they move. They migrate south to the spawning grounds and in the Straits of Florida and the Caribbean, and they move back north to feed on Georges Bank and Grand Banks and some of those other highly productive feeding areas. And they do this on an annual cycle. They’re not moving further offshore, it’s just that the populations that are left are further off shore. That’s why the boats are having to chase them further off-shore. I don’t have any data that could prove or establish that, or disprove it. I mean it’s a hypothesis. But we’ve seen this with other species; that when you reduce the population through fishing that the range of the stock shrinks, and this is just another example of that. There’s nothing unique about this; we see it will all sorts of species.
One of the other problems with managing this fishery is that long-lines, as I think you mentioned, long-lines take the whole complex — they catch swordfish, they catch tunas, they catch billfishes, they catch sailfish, they catch a whole suite of fish in the ocean. And so one of the problems with trying to manage this gear is that if you reduce the amount of targeted sword fishing — swordfish long-lining, which has happened, partly because the stocks are declining and partly because of quotas and for other reasons. And these vessels then go tuna fishing, for example. There’s a fairly active yellowfin tuna fishery in the Gulf of Mexico where they continue to catch juvenile swordfish as a by-catch. So this is a real challenge for managing this fishery - the fact that, to a large extent, it is not very species selective. You put a long-line gear in the water, at least the way they’re fished now, and you tend to catch a whole suite of fish. For the fisherman, many of these fish are highly valued and they’re happy to catch them. But from the standpoint of trying to manage the fishery, it becomes a very difficult challenge because you. If you put a quota on swordfish, the quota’s taken and the boats go and fish for big-eyed tuna or for yellowfin tuna and they continue to catch swordfish and discard them over the side. And especially in the case of swordfish, because they’re mostly dead, you end up just increasing your dead discards. And so this is another aspect of managing this gear that it makes it very difficult. The Japanese, for example, don’t target swordfish at all, and yet they’re one of the biggest swordfish harvesting countries in the world because they catch them in the course of harvesting tuna. So it’s very hard to manage this gear. Actually I’m doing some research now on trying to make the gear more selective. And it’s sort of interesting because as it turns out one of the reasons why the gear is not selective is because what happens to it once it’s in the water is not intuitive with what’s going on down there. And the only reason I know that this is happening is because we put instrumentation on the line. And we can monitor the depth and the temperature of the hooks and we can determine the performance of the gear. We have hook timers that we use so we know the actual time that a fish struck the bait, and we know what depth the gear was when that bait was struck and what temperature the gear was. And what happened is a complete surprise. It was a complete surprise to me, and it was a complete surprise to the fishermen on this boat that I was working with. Because we work on commercial fishing boats, the gear, instead of laying in nice even scallops in the ocean, which is how everybody pictures long-line gear as sitting, instead was meandering all over the water column. Sometimes it would come way up, almost close to the surface. Other times it would go down, hundreds of meters. I mean not just little meanders, but these huge vertical meanders, and I think that largely explains why the gear is so non-selective because there’s no control over where that gear is fishing. So, the thrust of my research now is to try to determine how you can set the gear so it stays where you want it. Because if you know that swordfish are going to be found above the thermocline, for example, in a certain water temperature, and you can keep the gear there, then you’ll catch swordfish. If you can’t keep the gear there, you’re going to catch everything else — you’ll catch billfish and mako sharks and tunas and everything else that you’re not after. So in the last few years this has been one of the thrusts of my research. The gear is here, I mean it is very widely used by lots of countries and if we can’t find another way to fish, at least let’s do the best we can with the gear that’s out there. I think without having the instrumentation board, the fishermen had no idea that this is how his gear was performing. I think that most fishermen don’t realize that. And if you don’t know how your gear is performing, it’s kind of like putting a bottom trawl down without knowing how deep it is and what kind of bottom you’re over. It’s just like a crap shoot. So by trying to figure out ways of fixing the gear in the water column and getting it to set where you want it and the temperature you want it at, I think you can make it. What I’m trying to do is figure out ways of making it more selective. Because as I said, that’s one of the problems with the gear. It’s non-selectivity. The more selective you can make the gear, the more options you have for management.
I think so. And, you know—it’ just the evolution of the fishery. And I think you’re going to see it more and more, and particulary as the regulatory climate gets more and more oppressive and you have to work, not just to figure out how to catch fish but also how to catch just the fish you want and not have a discard problem. This is a big problem, not just in long-lining but in a lot of fisheries. You have to figure out how to fish for the market, the prices. And it’s become very complICCATed, and as regulations get more and more restrictive—where you can fish, when you can fish, you have to make the most out of every hook. Right now, the average long-line fisherman, many that I’ve worked with, their solution to not catching enough fish is to put more gear in the water. If we ain’t catching enough fish in 20 miles of long-line, let’s put in 30 miles of long-line. But the intelligent fishermen, instead of just putting more gear in the water and having more by-catch and wasting more bait and more light sticks, figure out how to hone in on the fish that are there and how to concentrate their gear in areas where they’re more likely to catch fish, where the catch rates are going to be higher. And that’s the fisherman that ultimately will be successful. And no matter what the management regime is, no matter what the regulations are, there will always be a small percentage of fisherman that are going to be successful. And they’re the ones that fish more with their heads than with their backs. And that’s where we are right now. There are no more easy fish left in the ocean. And to be successful as a fisherman you have to be pretty clever and I think pretty analytically. And especially with long-line fisheries because you’re dealing in such an alien realm. You know, you have to rely on instrumentation and you have to rely on remote sensing and this sort of thing. No defining areas in the ocean that you can see visually. Those days are going — the smell’s right here. I think those days are pretty well gone.
You’ve got navigation equipment that you never had. You’ve got temperature-sensing gear that you’ve never had. You’ve got global positioning systems, and temperature probes and acoustic doplar current profiles, for god sakes, I mean—oceanographic vessels don’t all have acoustic doplar current profiles. This is pretty sophistICCATed instrumentation for a fishing boat. And they make use of that. And that isn’t captured by the catch per hundred hooks. So fishermen that are very heavily instrumented can maintain a catch rate that, without that instrumentation, I don’t think they could. So you tend to overestimate the stock size, from looking at this kind of catch and effort data.
Based on landings and log books. You know, somebody’s fishing the same 20 miles of water with the gear I always fished, but it’s not the same. It may be the same 500 hooks but it’s a whole different 500 hooks. You’ve got 14 different colors of light sticks, and people are dying their squid and they’re using much higher quality monofilament thinner and more invisible. You’ve got different ways of rigging baits, and that’s just the tip of the iceberg. Then you’ve got all the electronic gear that didn’t exist 20 years ago. Fisherman actually and honestly tell me, "If we used the gear that we were using 20 years ago today, we wouldn’t catch a fish — nothing. " And this is from people who are experienced, who have fished. And the changes took place very rapidly. It really has only been in probably 20 years that all of this has taken place — all these changes in materials, in the quality of the monofilament and hooks and all that — just the hardware. I don’t know of a boat that doesn’t have a computer on it now. I mean you can’t go into a wheelhouse now without at least one computer and weather fax machines, and GPS, and downtown probes, and surface temperature probes. It’s a different fleet than it was even 10 years ago.
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Dr.
Steven Berkeley is a marine biologist at the Hatfield Marine
Science Center in Newport, Oregon and former staff scientist
with the South Atlantic Fishery Management Council. He has
conducted research on the status of North Atlantic swordfish
populations.
Is it true that the many swordfish are being caught before they
have a chance to breed?