Earth & Sky

The following individual was interviewed for today’s show. Our thanks to:

Dr. Daniel Pauly
Professor
Fisheries Centre
University of British Columbia
also
Science Adviser
FishBase Project International Centre for Living Aquatic Resource Management (ICLARM).

Interview with Dr. Daniel Pauly:

ES: Please tell me a little bit about yourself.

DP: My name is Daniel Pauly, and I’m a professor of fisheries at the Fisheries Center in the University of British Columbia in Vancouver, Canada.

ES:

DP: What we do is, we are one of the few groups in the world, perhaps the only one, that looks at fisheries as a global phenomenon. We have developed methods for mapping the catches of fisheries across the entire world ocean. And we present as maps ? we call them weather maps ? what other people often present as numbers. And these maps allow us to see what is happening to the ocean, just like when you see a weather map. And what we have mapped then is the catch, and from that we have derived – using various modeling techniques ? maps of the biomass of the ocean. The biomass is the amount of fish at anytime in the water. And for the North Atlantic we have already presented the results at the meeting of AAAS ( American Association for the Advancement of Science 2002), and we’re showing that for the North Atlantic this biomass of fish, the amount of fish on the sea, has been drastically declining especially for the large fish that we like to eat, the fish that are on top of food webs – the cod, haddock, the flat fishes, the tuna, etc? They have declined drastically. They are about 1/3 of what they were in 1950, and 1/6 of what they were at the beginning of the 20th century. So they’ve been very strongly affected by fishing. So that’s what we do. And in the process of mapping things, we’ve also discovered that the world fisheries catches have been declining. And the impression that the catch was continuing to increase came from all the reporting of catches from the Peoples Republic of China. So this is some of the work that we’ve been doing.

ES: Can you tell me a little about the science involved in the process of doing your research

DP: Basically, it’s a very small minority, the small number of fisheries for which we have records of, this fish was caught at this place at this time. And this comes from observers that are on boats. Now, this is very rare that such records are available. Usually, they’re confidentially anyway. So what we have done, is that we’ve constructed a series of interlocking databases where the first condition for something to be caught is that it is within the geographical range of that species. So if you catch, say, a ton of herring, it has to come from within the area inhabited by a herring. Second, if it is reported from within the exclusive economic zone of a country it has to be reported by a country that has access to that exclusive economic zone. That is usually the adjacent country or a country that has permission to fish in the water of that other country. And so we have assembled a huge database of the distribution of all the fish caught in the world and a database of all the access agreements that exist in the world between countries. And this way we can identify the overlap area between where a country may fish and where it can encounter a certain fish. And this is at the basis of our patch maps.

ES:

DP: These ### we call them “fishing down marine food webs.” Essentially, this consists of overexploiting the larger fish that feed on top of the food web, on top of the food chain. And these fish, say tuna, cod, the large halibut and so on, they regulate the marine food webs because they sit on top of them. So once they are removed, these fish are very fragile in terms of being overfished because they’re long lived, and they’re very easy to, they don’t replace themselves very fast. So if you fish them very strongly, then they collapse. And then we have turned to the prey fish of these top predators, and we’re now catching the fish that were being eaten by these top predators. Also, we’re catching animals that are even lower in the food chain. And so we are moving from large, slow growing, long lived fish, to smaller, faster growing fish that are lower in the food chain. And this process of going down the food web, it would say is a good thing because it provides substitutes for what we have lost. But at the end of this development we will have ended up eating jellyfish, catching jellyfish. In fact it is happening already.

ES:

DP: Most of the fish catch, about 90% of the global fish catch, comes from the shallow waters, within 60 feet around the continent. And these so-called “shelves” are completely, devastatingly overfished throughout the world. The biomass, that is the amount of fish that is left there, is about 1/10 or less than what it was 50 years ago. In most cases the devastation is mind boggling. And the figure I was citing before, for the top predators, they are conservative estimates. In fact, in various places, you have 5% of what there was before. For various species, cod for example in New England, is about 2 or 3 or 4% of what they were before. They have very small numbers that are left. And so you have to imagine that these shelf areas, shallow areas just off the continent, ? the equivalent of clear-cut forest. That’s the equivalent. That’s what we have done to the shelf systems around the world. This is in effect much stronger, this effect fishing, than say the effect of pollution, which people think is the major impact that we are having on the ocean. Actually, this is much stronger.

ES:

DP: There’s two effects. One is simply the removal of fish by fishing, whether it’s environmentally friendly fishing or not. Simply the fact that we remove fish. If we remove fish, then it has an effect on the ecosystems. The other one is the habitat modification. When we use bottom trollers, we drag big, heavy nets on the ground. These troll nets, they have chains, they have big wheels. In fact there’s legislation on the way now in the House of Representatives (Canada) to abolish, or limit the size of those wheels. These big wheels and these chains that are meant to stir up the ground to dislodge the fish that are trying to hide at the bottom, they destroy everything that grows on the bottom that attaches itself to the bottom. And they turn rock, diversified habitat that is good for the fish into big, giant mud baths, mud flats. And very few animals can live in these mud flats, or sandy flats. Very little life can actually be maintained there. So the habitat modification by the fishing, especially bottom fishing, dredging, etc? is the next big problem.

ES:

DP: Well, small scale fishing in principle do not do this kind of devastation. However, a lot of small scale fisheries can remove fish as from an area, as much as industrial fishing can. Further, in many developing countries, small scale fisheries, in their desperation are using explosives which destroy reefs, or poisons to stun fish. At that point, as it is now small scale fisheries have the same impact as industrial fisheries. But I think that, for every country in the world, we have to consider that what is a small scale fishery in the Philippines is not the same as a small scale fishery in Canada. The boats that are considered small scale fishing in Canada are the big time boats in say the Philippines. So we have to differentiate there. But in any case we can say that small scale fisheries generally utilize the movements of the fish. It’s the fish that catch themselves. Whereas in industrial fishing, you move the gear, and you move the boat. And in that case you spend much more energy catching the fish. So, industrial fisheries, they are not economically or ecologically very efficient, in terms of pure consumption, etc?. And really what keeps them going is subsidies that the public is paying, that the taxpayer is contributing. In the North Atlantic, for example, the fisheries, mainly the industrial fisheries, get about 2 1/2 billion dollars every year from North America, that is the U.S. and Canada, and the European countries. Canada supports small scale fisheries with the U.S. supports almost all its fisheries and Europe as well. So that is a very bad thing, because the taxpayer who would like to see the sea protected is in fact subsidizing its destruction.

ES:

DP: One of them is the simple ? but it’s not simple ? the reduction of fishing capacity and fishing asset. In other words, less boats. This would benefit the ecosystem immensely. It would benefit the stocks, and it would benefit the consumers, actually, because if we had less fishing, we would have more. This is something that most people cannot get in their heads, that fisheries ? if they are overfished ? you can rehabilitate them by fishing less. And then you catch more by fishing less. So that’s one thing. Abolish the subsidies that are awarded to the fisheries, industrial fishing industry. The other thing is to create Marine Protected Area, a zoned area where only certain fishing practice is allowed and would have at their core, areas where you cannot fish at all. That is, marine reserves. These marine reserves would enable the stocks to replenish themselves, and especially these old fish to rebuild their biomass. And, in the process, when the big, large female would produce the eggs and the larvae ? which are exported out of the main reserves ? and would support the fisheries themselves. Because right now we’re losing these large females that maintain the fisheries through their young. So these marine reserves would be an important thing. And we don’t have any to speak of in the North Atlantic, in the North Pacific; we don’t have any to speak of.

ES:

DP: Well, they are accidental areas. For example in Cape Canaveral an area of Florida was protected by the fact that no fishing was permitted close to the launching pad for the shuttle. Now, in that area, there are lots of big fish. These big fish have begun to produce the trophy fish that the sport fishery is so happily catching now. So in the D.C. area we have a similar thing. Where, around the perimeter of a prison, that is somewhere in the Georgia Strait, you find the last abalone, which exist in the area because everywhere else they have been taken. So we have lots of accidental Marine Protected Areas. On Georges Bank there is also one. A certain area of the Georges Bank was closed to protect cod, juvenile cod. And as a result, the scallop, which had been very strongly fished, bounced back, and generated an absolute bounty for everybody. So that is the point. Close certain areas so that the ecosystem can replenish themselves.

ES:

DP: Let me explain. In the sea, the first step in the food chain are little algae, little plants that are microscopically small. You cannot see them with the naked eye. They’re called phytoplankton. And they are consumed, these plants, by flea sized organisms that are called zooplankton, that is, little things called copepods, etc. And these flea like animals, they are like the cows of the sea. The feed on these little plants. And the little fish feed on these zooplankton. So if you count the levels, the steps in the plants to the fish, you have: the first step goes from the plants to the zooplankton, and then from the zooplankton to the small fish. But the small fish that feed on zooplankton, they are not really table fish that we can eat. It’s only the fish that eat those small fish that we can consume. And, let’s say, a cod feeds on little fish, that would be called **kapling, we don’t eat those, and these **kapling feed on the zooplankton. And so the cod has something that is known as a trophic level, a level a level in the food web of four, because it is three steps removed from the plants. Now, if you fish down the food web, that means that the fish that were on top that feed on the fish disappear, and you’re left only with the small fish that are low in the food web. And these are usually small organisms that are not so valuable and so tasty as the big ones that are on top of the food web. And marine ecosystems function that way because they have lots of animals, lots of production at the low levels, but consumable animals for us at the top of the food web. So when we fish down the food web we are changing the structure of the ecosystem of the marine habitat.

ES:

DP: If we’re fishing down the food web, we are not catching the kinds of things that we really want. We end up with organisms that only some people can like. Jellyfish consume zooplankton. And some people eat jellyfish. But it’s not the kind of thing ? at least in the west ? people like to eat. But as we remove the fish, the good quality fish from the sea, this is what we end up, what we’re left with.

ES:

DP: One reason why the damage that fishing has done to the ocean, one reason why the public at large doesn’t see it well is because every generation has a different perspective of what the sea is, and therefore ought to be. That is, when you start ? and you’re young, say a researcher or even somebody who’s looking at the beach or going to the fish market ? what you see is the standard. Now as you grow older, you can see certain things disappearing that you used to see. And then at the end of your life, you can end up complaining about having lost all of this. Now, the next generation, your children, will start themselves where we left off. They will have as a standard, what they see when they were young. And so every generation has a different perspective of what ought to be and what has been lost. And the older generation has usually failed to pass on to us, to the next generation, what it was that was there. So when we read their account, we do not believe them. When we read that there were grey whales, for example, along the east coast, that you could walk along the beach and catch great big lobsters, that the Chesapeake Bay was just absolutely full of oysters, etc? all of these stories, they sound so strange. And unless you have photos showing it, people don’t believe it, really. And so these accounts of extreme abundance are dismissed. And because they are dismissed, we just try to maintain what we have, which is a miserable leftover, miserable remnant of a past abundance. So we should actually rebuild what was there based on the accounts of what was there, which therefore could come back if we just gave it a break. That’s the shifting baseline story, the fact that we have this different reference for every generation.

ES:

DP: We have to reduce fishing effort massively, and we have to set up large areas where there is no fishing. There’s no way of getting around that.

ES:

DP: The opposition is a fishing industry that loves this subsidy money and loves to continue to do what it does. There is no doubt about it. When a group of fishers have over fished a place, it’s very difficult for them to accept that they have to quit. It’s like a bunch of loggers, there is a forest there, and they have to cut it down. Then they would like you to support them to do the same thing to the next forest. Or they would like you to pay them money because there’s no more trees to cut. I mean, it is absurd, but that’s what we do.

ES:

DP: The world catch as it is now, is not sustainable because it’s composed of the sum of a large number of fisheries which themselves are not sustainable. Right now we have established that there is a downward trend in the world catch. I think that it will continue, that downward trend, unless we make the individual fisheries – of which the catch is composed ? sustainable. In order to make it sustainable we have to reduce the fishing effort that is deployed in each of them. We have to create areas where the stocks can replenish themselves, and these are marine reserves. There’s no getting around it. We cannot avoid global warming if we continue to produce so much carbon dioxide. There’s no way of getting around it.

ES:

DP: At the risk of sounding cynical, I haven’t been surprised by anything we found, because this sorry state was known for the individual fisheries, so it’s not surprising that we should find a similar picture when we combine this with a few of the global ecosystem. I’m not surprised at all. What else is there? Obviously it has to. If you aggregate a number of stories, then you end up with an overall story that is similar to the individual stories, like an average.