Fishing down marine food webs
Image: Greenpeace; White-tipped shark caught in fishers' net
The World's last major "Wild" food resource is in jeopardy. That is the conclusion of an article entitled "Fishing down marine food webs," which was published last month in the journal Science. Here Jennifer English surveys the main findings of that article and interviews Dr. Daniel Pauly the article's senior author. (For further information and links, see References.)
March 16, 1998: Events such as the collapse of the Peruvian anchovy
fishery in 1971, and the collapse of North Atlantic cod fishery in 1991
make it clear that the world’s last major "wild" food source is in jeopardy.
Unless radical changes in fisheries management occur, the diversity of
ocean life will be greatly impoverished. For the fishing industry, the
oceans will become aquatic deserts offering little to harvest beside jellyfish
and lanternfish.Oops. Anchovy stocks have proved
to be wildly oscillating in their biomass. Why is not yet understod but
ecologists' concept of 'stability' may need to be changed as many stocks
(including invertebrates) are 'stable' in their oscillations. A fishery
is established in the 'good' years, to collapse in the 'bad' years without
having caused that collapse.Similarly for sardines and herring.
Note that lantern fish are small, living sparsely in mid-water, migrating upward to food-rich zones by night and living in dark depths by day. They are an important food source for oceanic 'blue-water' fish.
Such is the conclusion of the article "Fishing Down Marine Food Webs," published last month in Science, the journal of the American Association for the Advancement of Science, by a group including scientists from the University of British Columbia and the International Center for Living Aquatic Resources Management (ICLARM) in the Philippines (1).
It is a shame that journals like Science and Nature have so uncritically embraced politicised science like global warming. At least readers can cancel their subscriptions. Read our Hall of Shame.
In their study, the scientists analyzed United Nations Food and Agricultural Organization fish catch data against food web models (2) to show how, since the 1950’s, global fish harvests have shifted down the food web away from species of higher trophic (food web) level (predators such as halibut and tuna) to species of lower trophic level (plankton-eaters such as anchovies). This shift has occurred as populations of predator fish have been decimated by over-fishing and fishers have been forced to harvest what is left, species of the predators’ prey.
The study demonstrated this shift by means of a scale which assigns top predators such as killer whales a trophic value of 5.0, tuna and cod a value of 4.0, and species at the bottom of the food web, like anchovies, a value of 2.0. Although the study acknowledges that some of the catch data from the Southern Hemisphere may be unreliable, the general trend is evident. Since 1950, the average trophic value of fish caught dropped from 3.4 to 3.1 in oceans and 3.0 to 2.8 in freshwater. The largest decline was off the Eastern coast of Canada and the US where the level has dropped from 3.4 to 2.9. Bravo. It's good to have such data.
Alarmingly, this slide has not been accompanied by larger catches. This is contrary to expectation. Normally, as one moves down a food web, biomass increases. Instead, fish catches have stagnated as fishers have moved from top predators to species at lower trophic levels. One reason for this effect is that once a top predator has been depleted or exterminated by fishing, alternative predators, which are of no commercial value, thrive in the absence of competition and thus deplete the biomass of prey species at lower trophic levels. Perhaps not so. Fish catches are driven by demand vs costs.
The Science magazine article shows how this pattern is overlooked in
present day fishing management strategies that place moratoriums on the
harvest of individual species, such as cod in Atlantic Canada. Reliance
on Moratoriums on the harvest of particular species is ineffective if the
food source of the protected species is being depleted either by fishers
or by alternative predators. To prevent total species collapse, the
study suggests, "fisheries management will have to emphasize the rebuilding
of fish populations embedded within functional food webs..." (1) instead
of focussing on the health of one particular commercially harvested species.
This broader approach to conservation could be accomplished with the implementation
of more "no-take" Marine Protected Areas (MPAs).
Fantasy without proof?
An Interview With Dr. Daniel Pauly
Dr. Pauly, senior author of the Science article discussed above, answers questions about the global fisheries crisis and the concept of "no-take" areas:
naturalSCIENCE: How does over-fishing compare in its impact on aquatic
ecosystems to other disruptions such as pollution and climatic aberrations
such as El Niño?
Dr. Pauly: On a global basis there is no environmental factor affecting marine communities (i.e., removing fish and bottom habitat) that is comparable to the fisheries in impact. El Niño and other local effects modify the range and recruitment of various species, but do not remove entire communities, i.e., they do not cause species to become extirpated throughout most of their range as the fisheries do. After all, fisheries are meant to kill fish. It is the public who believes that the 'environment' disrupts fish resources, and it is a useful smokescreen for the industry. Oops what a nincompoop.
naturalSCIENCE: You think it unjustifiable, then, to blame seals (See
Below) for the slow recovery of Canada's Atlantic cod fishery?
Dr. Pauly: It is a joke to blame seals for the slow recovery of cod stocks. Humans and seals coexisted for hundreds of years around Newfoundland, and the cod fishery was not much affected by seals or the environment. Obviously, the seal consumption of cod will look large relative to the total cod stock if the cod biomass is reduced to abysmally low levels by the fishery.Oops. By the same reasoning cod fishing is not much affected by present-day fishing because we did so for hundreds of years!
naturalSCIENCE: What would be the best way to implement the "no-take"
Marine Protected Areas suggested in your report?
Dr. Pauly: The best way of implementation would be to involve the public at large in a debate about the resource. After all the resource doesn’t belong to the industry, but to all citizens. The alternative to setting up Marine Protection Areas (MPAs) is to gradually lose all larger fish species presently exploited.
naturalSCIENCE: How much more of the oceans would have to be put aside
in addition to the 1% that is currently protected?
Dr. Pauly: About 30-50% of the oceans would have to be put aside in MPAs. There is much research being done to determine what would be the optimum properties of such sites.Oops, there is no scientific basis for this. See target sizes.
naturalSCIENCE: What role do you see aquaculture having in terms of
controlling fish harvests, and how does intensive fish-farming affect species
Dr. Pauly: Aquaculture has no bearing on the control of fish harvests. It may actually be deleterious to fisheries management. With the growth of the fish-farming industry, wild fisheries management may be seen as superfluous. In terms of species diversity, in the North Atlantic, salmon farming has a very negative effect on the genetics of wild salmon.
naturalSCIENCE: To what extent are Western intensive fishing techniques
used in the developing world, and, if "no-take" areas are needed, do you
foresee resistance by developing countries similar to that shown in negotiations
over reduction of carbon dioxide emissions?
Dr. Pauly: Western intensive fishing techniques now dominate in the developing world. Some of the first "no-take" MPAs were implemented in developing countries in the Caribbean and the Philippines, with very positive results. These experiences were worthwhile because the MPAs actually increase fish catches in the adjacent areas. False.
Dr. Daniel Pauly is currently a Professor at the UBC Fisheries Centre,
Vancouver, Canada and is also the Principal Science Adviser for the International
Centre for Living Aquatic Resource Management (ICLARM), Manila, Philippines.
He has taught on five continents in four languages about fish population
dynamics. He has authored, co-authored and edited over 300 scientific articles,
reports and books.
What Is the Case for Killing Seals?
There is little published scientific evidence to justify the government-subsidized seal hunt as a means of restoring cod stocks in Canadian waters off the coast of Nova Scotia and Newfoundland. Such was the view of 97 scientists from 15 countries who signed a petition opposing the hunt at the Eleventh Biennial Conference on the Biology of Marine Mammals in Orlando, FL (14-18 Dec. 1995). The petition stated:
As professionals in the field of marine mammal biology we disagree with the Canadian government's statement that North Atlantic seals are a 'conservation problem'. All scientific efforts to find an effect of seal predation on Canadian groundfish stocks have failed to show any impact. Overfishing remains the only scientifically demonstrated conservation problem related to the fish stock collapse. If fishing closures continue, the indicates that the stocks will recover, and killing seals will not speed that process. (International Marine Mammal Association) (3)
Despite a lack of evidence, this year’s hunting quota in Canada is 275,000
seals. Observers report that the actual number of seals killed, including
those whose carcasses are not recovered, may exceed the quota by as much
as a factor of four (4). This greatly exceeds the 170,000 seals that Canada's
Department of Fisheries and Oceans estimates can be killed in a year without
depleting the population (5).
(1) Pauly, Daniel, Villy Christensen, Johanne Dalsgaard, Rainer Froese and Francisco Torres, Jr. 1998. Fishing down marine food webs. Science 279:860-863.
(2) Site with links to data used in the study Fishing down marine food webs. Target file now deleted from Web.
(3) The Canadian Harp Seal Dilemma: An analysis of the seal hunt with references.
(4) Mowat, Farley. December 19, 1997. Letter to the Editor, (Toronto) Globe and Mail.
(5) Gowdy, Barbara and Louise Dennys. March 9, 1998. How the hunt earned our seal of disapproval. (Toronto) Globe and Mail.
50 years ago, the oceans were full of big fish. Not anymore. But today, some stocks are on the verge of collapse, and what's left isn't much bigger than bait, according to a recently released study. "The point is our greed is limitless. Our demands are limitless," says UBC fisheries professor Daniel Pauly. Pauly adds that historically, whenever a new fishery was discovered, within a decade, they had to quit because it was gone. Then, he says, the fisheries managers arrive.
"So management in expanding fisheries is always developing new ways
of closing barns out of which the horses have long escaped. So in
a sense fisheries managers is decorating the barn door or having bigger
locks, triple locks and quadruple locks, but the horse is gone because
it takes such a short time for the population to be reduced."
The sustainability of fisheries, historically, is largely a matter having no access to the bulk of an exploited population. Fisheries persisted when most of the targeted fishes were in deep, offshore waters, or in areas adjacent to lands with low human populations. Thus, fisheries earlier had large, no-take marine reserves.
Modern fishing technology relies on methods that originated with submarine tracking and other forms of warfare (acoustic fish finders, radar), and preservation technology (artificial ice, blast freezing) which immensely expanded the reach of distant water fleets. Combining this with Cold War technology (geo-positioning systems, detailed, real-time maps of oceanographic features, detailed maps of the sea bottom), fishing vessels now can and indeed will catch, unless restrained, the last fish concentration in the world ocean.
Marine reserves are thus not 'new,' not a new invention of arm chair ecologists, designed to torment hardworking, over-regulating fishers.Rather, they would only re-establish the natural structures which have enabled earlier fisheries to maintain themselves for centuries.
Getting this message across to a wide public is urgent, given the hardening
stance of the fishing industry against marine reserve, and thefact that
presently, they cover an infinitesimally small fraction of the world ocean.
Early fisheries was centered on large species, but their numbers have decreased and so the fishing fleets are catching smaller and smaller species that are at lower trophic levels in the food web (hence the title of the lecture).
1) a food web is composed of various species that eat other species. Primary producers (phytoplankton) are at the first trophic level and animals that eat plants (herbivores) are at the second trophic level and animals that eat animals (carivores) are at the third trophic level. In some food webs, some animals are at the fourth or fifth trophic level. For example tuna is at the fifth trophic level.
2) The trophic level of an animal defines how far it is removed from the base of the food chain (the phytoplankton).
3) Ecological Efficiency or trophic level transfer – 10% of the biomass of the lower trophic level is transferred on to the next higher trophic level. So if you fish down one trophic level and catch smaller fish this is more efficient in terms of the food web since it did not take as much primary production to produce the fish at the lower trophic level.
The mean trophic level of the global fisheries was near 4, but now it has decreased to about 3.2 (i.e. fishing down the food web). The estimate is for a decline of about 0.1 trophic level per decade.
For example, when the cod fishery collapsed in eastern Canada, the invertebrate fishery increased (e.g. snow crab) since the cod and crab compete for similar food.
BC fisheries – ling cod, sturgeon, and humpback whales are either gone or almost gone.
Now hake (a bottom fish) is more abundant. Our goal is to have a sustainable fishery.
Historically primitive fishers started with large high trophic level fish/animals that were close to shore and easy to catch (e.g. sea cows that ate kelp).
Big animals often have a slow growth rate and therefore they cannot compensate for the high harvest rate.
When big animals/fish are gone, then fishers harvest smaller ones (the prey of the big ones)
New technology makes catching fish easy. Large bottom trawlers wipe out the bottom (benthic) animals.
Final result of fishing down the foodweb is that we may be catching zooplankton and jellyfish in the future.We will have to make new products out of these less desirable animals.
China – has been reporting very high catches (like the upwelling area off Peru – theworld’s largest fishery). But there is no upwelling off China, so how could this be true.
The large anchovie fishery off Peru is due to the upwelling of nutrients which results in very high primary productivity. Pauly estimated what the fish catch should be as a function of the known primary productivity off the coast of China. He concluded that China was over reporting!! (for political purposes).
Scientist and author Daniel Pauly says that we have caught most of the big fish, and now we are actually starting to eat the bait. Squid was just bait a while ago and now it's on our plates and we call it 'calamari'. Eating jellyfish may have seemed like a joke, but now it's reality. What we are seeing is a depletion of smaller species as we "fish down the marine food - web" or rather, eat our way down the fish food web - Ed.
It is difficult not to be a pessimist about fisheries, writes Daniel Pauly. Global marine catches, which had increased rapidly since World War II, stalled in the late 1980s then began a decline which will be difficult to halt. This decline is due to an immense, sophisticated technology being thrown at dwindling fish populations and to an increasing demand, driven by increased human population and incomes. The declining supply has been so far masked in the developed world, in part, by the availability of certain seafood products not previously available, such as farmed salmon, and by massive fish imports from developing countries.
Overfishing, however, is occurring in the developing world as well, and thus fisheries, globally, are due for wrenching changes in the near future. One clear indication of this is 'fishing down the marine food web', the increasing tendency of fisheries to land fish and shellfish from the bottom of marine food chains, often the prey of the larger fish previously targeted.
Fishing down marine food web provides low quality substitutes for the high quality fish we were accustomed to, and will inexorably lead us toward catching plankton, especially jellyfish. Yes, jellyfish, which are now turning from a specialty consumed around East Asian Seas into a product that is caught in the Atlantic as well, and exported across continents.
The fishing industry is, on its own, incapable of turning the 'fishing down' trend around, notwithstanding commentators who should know better than argue that all is well. One of these is the now discredited Bjørn Lomborg, who in his 'Skeptical Environmentalist,' implied from increasing global catch figures reported by the Food and Agriculture of the United Nations (FAO) that the underlying ecosystems must then be in good shape.
However, we now know that the apparent increases of global fisheries catches in the 1990s were due to China massively over-reporting its catches to the FAO. And we also know that catches can remain high (and in fact usually do) when stocks collapse, as illustrated by cod off Eastern Canada, which yielded good catches until the fishery had to be closed because there were literally no fish left.
But excessive catches are not even the whole story. Many of the fishing gear used to catch fish - bottom trawls foremost among them - literally tear up the habitat upon which these fishes depend. Quite a strange way to run a fishing operation, if you stop and think about it! Small wonder that some of the stocks exploited in this manner do not seem to recover.
Is aquaculture a solution?
Aquaculture, the farming of fish and other aquatic organisms could in principle help overcome the shortfall. However, the word 'aquaculture' covers two fundamentally different kinds of operations; let's call them Aquaculture A and B.
Aquaculture A, devoted to the farming of bivalves such as oysters or mussels, or to freshwater fish such as carp or tilapia, relies on plants (plankton in the sea, or in ponds, sometimes supplemented by agricultural by-products in the case of freshwater fishes) to generate a net addition to the fish food supply available to consumers. Moreover, because Aquaculture A is based predominantly in developing countries (mainly in China, but also in countries such as the Philippines, Bangladesh), it supplies cheap animal protein right where it is needed.
Tofu tasting tuna
Aquaculture B is the farming of carnivorous fish such as salmon or seabass, and increasingly, the fattening of wild caught tuna.
Salmon, seabass, or tuna eat flesh; they are, ecologically speaking, the wolves and lions of the sea. When fed only vegetable matter, e.g., soy meal, salmon do not grow well, and end up looking and tasting like tofu. As for tuna, there is no point even trying to feed them with anything but fish.
What this means is that the more of aquaculture B is done, the less cheap fish such as sardine, herring, mackerel and anchovies there will be for humans to buy and eat. Aquaculture B does not reduce the pressure on wild stocks: it increases it. It has led to massive imports, by developed countries, where Aquaculture B predominates, of meal from fishes caught and ground up in developing countries.
We won't elaborate on the coastal pollution and diseases emanating from the uneaten food and feces of operations that match floating pig farms in all their major features.
One reason why the practitioners of Aquaculture B can get away with all this is that the public at large assumes their operations to be similar to those of Aquaculture A, and to add to the global fish supply. Let's keep the differences in mind when we evaluate 'aquaculture.'
There is still time
There is still time for fisheries, but only if they are reinvented not
as the source of an endlessly growing supply of fish for an endlessly growing
human population, but as provider of a healthy complement to grain-based
diets. Particularly, fisheries cannot remain a free for all for a pillaging
distant water fleet; they can however, become a regular source of income
for communities whose members act in accord with the finite nature of marine
resources. One key element of such reinvented fisheries will be their smaller
size, and their reliance on fishes moving out of marine reserves, the protected
ocean areas that we must establish if we are to allow marine ecosystems
and the species therein to rebuild some of their past abundance, and to
share this with us.
Commentary to this article
Daniel Pauly is a respected fisheries scientist and a well known commentator on the effects of fishing on marine ecosystems. His article, although emotive is not alarmist. Pauly is correct in asserting that world fisheries are in decline although the problem is a more complex than is implied in his short commentary. The question is: "What is to be done?". Fisheries management as it is traditionally understood has failed to sustain many fisheries.
Paradoxically, some of the most spectacular failures (such as the cod collapse) have occurred in the Northern hemisphere where very good data and population models of fish stocks exist. By contrast, fisheries management in Southern hemisphere countries (South Africa, Australia, New Zealand, Chile) where research capacity is less has successfully sustained many commercial fisheries.
Why is this so? The answer lies not so much in the quality data collection and science as in the areas of politics, economics, and law. For example, while South Africa has a tradition of good fisheries science, control of fishing effort by allocation of fishing rights to a select few under Apartheid effectively prevented overfishing. The current trend to achieve sustainable fisheries is towards "rights based management". If a fishing right is secure, exclusive and transferable, there is an incentive to fish sustainably.
However, under an open access system, such as the "high seas" fisheries example Pauly refers to, the "tragedy of the commons" is inevitable (if I don't take the fish someone else will). In conclusion, we can no longer regard fisheries as a "commons" (as is the case with air, water and land and other natural assets) as this will lead to disaster. Our challenge in "closing the commons" is to find ways to balance the triple bottom line of ecological sustability, social equity (who has a right to fish?) and economic efficiency.
Commentary by Professor Peter Britz, Rhodes University, South Africa.
What's your feedback?
* Professor of Fisheries, Fisheries Centre, University of British Columbia,
Vancouver, and Principal Investigator of the "Sea Around Us Project,"
devoted to studying global fisheries impacts on marine ecosystems.
He is the author of a new book, In a perfect ocean.
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The following individual was interviewed for today's show. Our thanks to:
Dr. Daniel Pauly
University of British Columbia
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.
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 Ð we call them weather maps Ð 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 Ð 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, etcÉ 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.
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.
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, É 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.
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, etcÉ is the next big problem.
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, etcÉ. 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.
DP: One of them is the simple Ð but it's not simple Ð 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 Ð if they are overfished Ð 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 Ð which are exported out of the main reserves Ð 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.
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.
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 (capelin) 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 ou'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.
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 Ð at least in the west Ð 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.
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 Ð and you're young, say a researcher or even somebody who's looking at the beach or going to the fish market Ð 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, etcÉ 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.
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.
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.
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 Ð 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.
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.
(c) 2003 Environment Hawai`i, Inc. Volume 13, Number 12 June 2003
Talking Story With Fisheries Expert Pauly
Daniel Pauly has shaken to its very core the science of fisheries management. The New York Times has written that critics frequently lump him with two other "doomsayers" - Paul Ehrlich and Peter Vitousek - who form the "Peter Paul and Pauly" trio. Science magazine noted last year that Pauly "is arguably the world's most prolific and widely cited living fisheries scientist." He's variously described as brilliant, iconoclastic, irreverent, wickedly witty, but no one would ever describe him as boring.
This month, Pauly will speak in Honolulu at the meeting of the Western Pacific Regional Fisheries Management Council. Patricia Tummons, editor of Environment Hawai'i, recently interviewed Pauly by telephone from his office at the University of British Columbia in Vancouver.
Your work has brought a historical perspective to fisheries management.
Instead of looking at a fishery over a short period of time, as managers
used to do, you have caused fisheries to be regarded as reflecting changes
that occurred over centuries of human involvement with them. What inspired
this revolutionary approach?
If you try to identify a phenomenon, it is either in sharp focus or you can't see it very well. When it is not clear, you have two options. One is to try to use more powerful tools to analyze the data you have - statistics, mathematical models. That's what I think many fisheries managers do; they add statistical uncertainties around the estimates that the models provide, given the limitations of the data. The other thing is to do what physicists do - build a bigger machine to get better data. When physicists perceive something, say, a weak electric signal, or a little bit of light from a telescope, then what they do, rather than use a statistical approach, is to build a bigger machine, typically 10 times more powerful, and then the phenomenon comes into full view.
For us, we very often argue about the most recent three, four, or five years of a fishery. Is it going up or down? Should we increase or reduce fishing effort, or can we maintain it? In 1995, when I published this note on the shifting baseline syndrome, I pointed out that we miss out on a lot of what has happened previously by using a statistical approach. So in order to understand the last five years, we should put them in the context of the last 100 or 50 years - in other words, construct a bigger machine. That involves constructing time series in different places and interpreting them over the last five to 10 years in light of what has happened the last 50 years and beyond.
The same thing happens spatially. Fisheries managers look at one stock, at one time, in one place - say, over an area of a few hundred kilometers, which is the range of an inshore fishery. With offshore fisheries, the range is more, perhaps 1,000 kilometers, but still small given the range of the ocean. Given that fisheries are operating globally and that capital flows move between countries readily, and that fleets can actually move from one ocean to another, we decided to scale up fisheries analysis to become global. So our machine has a long time span and a broad reach.
And the data you then obtain when you look at fisheries on that scale are rather devastating. What you see is that catches, or, more precisely, catch rates, which are an indication of fisheries' health, are declining throughout the world. One confirmation of our line of work is coming out in May in Nature - a paper by [R.A.] Myers and [Boris] Worm looking at the global tuna fisheries. They find it takes 10-15 years to reduce biomass in a fishery by a factor of 10. This is very much in line with my experience and is what we see everywhere. In fact, compared with the analysis of Myers and Worm, we are actually quite conservative. In an article to appear in the July Scientific American, we will have maps showing how fisheries of the world have expanded to cover the entire ocean, dragging down the biomasses of especially large fish to a large extent. This is a global phenomenon, happening over decades. When people say it is not so, they are usually referring to a small area, one species.
Overall, would you say fisheries in the Western Pacific are in good health?
I have not yet looked at the Pacific with the same kind of focus as the North Atlantic. The Pacific as a whole has seen decline following World War II. There have been expansions of fleets - Japanese, and Asian generally, but also from North America, especially the United States - in the Pacific. And this is a result of the open waters of the Pacific, especially the tuna areas. It's the last frontier. It has been possible for many fleets to maintain profitability for a long time, mainly because of subsidies that they get. Undoubtedly, the biomass of the fish, of the various species of fish, are much lower than before, and they are much lower than they should be to support fishing under any of the normal models which require biomass to be 30-40 percent of unexploited stocks. The biomass of all species of large pelagics are well below that, with all kinds of implications.
When it comes to commenting on the management measures in the area - there are two standards, an absolute measure and a relative measure. In general terms, the United States is generally doing better than other countries, when you make a scale and compare adherence to rules, willingness to enforce, et cetera. When you look at the absolute scale, it looks very bad, because the stocks in the areas for which the United States is responsible are not doing much better than anywhere else - a little better, but not much. And so it's a tricky question. I will be speaking in Hawai'i on this, and I don't want to steal my own thunder.
You touched on the issue of subsidies. Could you expand on that?
Subsidies encourage a continuation of fishing on stocks that are depleted. It's the catch per unit of effort that determines whether you can continue to fish. And effort translates into cost. If that is reduced by subsidies, you can remain profitable with lower catches, which means you can afford to reduce the stock further. So subsidies have the exact opposite of what lawmakers intend. Usually lawmakers are interested in getting a fishery going and keeping it alive to benefit more and more people. Subsidies have the opposite effect; you encourage, almost force, a fishery to develop further. Subsidies are what you need to bring a fishery to collapse.
In the North Atlantic, the pessimistic estimate is that subsidies amount to about 20 percent of the price of the fish. This means that the bulk of the fleets would not break even if they were not subsidized. Remove the subsidies from the North Atlantic fleet, and it would be largely bankrupt. I suspect the same thing is found in the Pacific.
One difficulty in talking about subsidies is that they come in different forms. One country will always see subsidies in the operation of other countries' fleets, but not their own. You need a standard definition and to apply it rigorously. We haven't done that for the Pacific yet, but are planning to do so as part of a global analysis. At the moment, there are two estimates of the amount of global subsidies floating around. One is that they amount to between $30 and $50 billion a year, the other is $50 to $80 billion a year. Of these two, the larger puts the value of subsidies as roughly equal to the value of the entire annual fish catch. The lower one puts the value at 20 to 30 percent of the value of fish. I'm not sure how the higher one was obtained.
With regards to fleet operation, subsidies begin with fuel subsidies. It can then continue with permission to import tax-free second-hand vessels in some countries, or in the United States, you get a subsidy when you have a boat built or you have credit guarantees. Then it continues with the whole operation of your fleet, with the research required to operate a fleet being subsidized by the National Marine Fisheries Service, who tells you where you should go to go fishing by providing maps on where the productivity is. And then it continues with subsidies at market level, for example, when fishers' incomes are subsidized by a price support system. (This form of subsidy is common in Europe.) So subsidies can vary. In Canada, for example, fishers receive unemployment benefits beyond what other workers would get. Different countries have different ways of giving subsidies. But the effect is the same.
There has been a lot of talk of ecosystem-based fishery management. Some even suggest that rather than target single species at the highest levels of the food chain, such as tunas and billfish, it might be better to utilize a broad swath of fish, including fish now discarded as bycatch. Nobody has done the research for ecosystem-based fisheries management. There is no such system in place, and no one knows what the implications would be. What we do have is a concept pushed by non-governmental conservation organizations that advocate ecosystem-based management as an approach in which you consider all elements.
If you want to continue business as usual, though, you can take this concept and subvert it. For example, Japan is going around saying that ecosystem-based management requires that all trophic levels should be exploited, and that we should therefore include whaling as part of an ecosystem based approach. So what you have is a complete perversion of the notion of leaving a chunk of ecosystem intact - that is, unfished areas - so the system can recover. You end up with exactly the opposite: exploitation that hadbeen limited to a certain extent becomes wholesale, occurring at all levels.
One often hears the claim that aquaculture will provide a significant role in meeting market needs in the future. Any thoughts on this? And, as a corollary: there is a proposal for an open-ocean mariculture operation off the Island of Hawai'i that would use wild-caught juvenile yellowfin tuna as seed stock. Is this a problem?
[Loud laughter.] The market for luxury fish products can be met by aquaculture, but it will not meet the demand for food by people who need fish as a source of cheap animal protein, that's for sure. One has to differentiate between the food that people need to eat - animal protein, carbohydrates, vegetables, all elements of a balanced diet - and food that we eat because we're invited to a party and are served caviar. Aquaculture comes into play as a net source of protein when you farm animals that don't require ground-up fish as food. Shellfish, such as oysters, cockles, you farm these, and that's a net addition to seafood. But if you farm salmon, the salmon you produce is not a net addition to fish production, because you need more fish - herrings, sardines, and the like - to produce the salmon than what you produce as salmon. So it is much better to consume 'forage' fish directly.1. "Anecdotes and the Shifting Baseline Syndrome of Fisheries," Trends in Ecology and Evolution 10(10): 430 (1995).
Mariculture, or rather, fattening, of tuna is already happening big-time in the Mediterranean. There are a couple of problems. First, the tuna that are caught for fattening are not counted as part of the catch quota, even though they are removed from the reproductive population. Second, the sardines and anchovies that go to feed these tuna are diverted from the consumers in the Mediterranean that eat these same fish. It's causing untold grief. These operations sell the tuna in Japan at such a high price that they can afford to pay good money for the tuna feed - much more than what the local market would pay for the anchovies and sardines in question. This is a crazy operation in terms of protein and in terms of energy, but this kind of thing is happening because you can concentrate money in a place and divert money to you. People who consume sardines don't have the same pull as someone who invests in this kind of thing. We shouldn't call this aquaculture at all. It's a feed-lot operation. And feedlot operations require lots of feed, and in these cases, that feed will be fish that could be eaten by people.
Jellyfish for lunch? It's no joke, says scientist
As traditional fish stocks decline, some nations are turning to eating lower on the food chain
By ROBERT McCLURE, SEATTLE POST-INTELLIGENCER REPORTER
VANCOUVER, B.C. -- It's your wedding anniversary, so you go out for seafood. As you and your mate reflect on your years together, you're both salivating in anticipation of a fine meal of ... Jellyfish?
That's the picture of the not-too-distant future painted yesterday for
1,500 fisheries scientists from around the globe by one of the world's
leading fisheries researchers, Daniel Pauly of the University of British
Kicking off the World Fisheries Congress, the veteran scientist showed how people's growing appetite for seafood has driven fishing boats from industrialized countries ever farther into Southern Hemisphere seas controlled by Third World nations.
It's a pattern also reflected in Puget Sound, where commercial fishing has virtually disappeared but a Seattle-based fleet goes all the way to Alaska to land the nation's biggest fish catch.
Pauly recounted how, as traditional fish stocks have declined, people in Third World countries increasingly have turned to eating lower on the food chain, even taking in the likes of sea cucumbers and sea urchins -- "stuff that eats dirt," Pauly said.
"When we first presented this, it was a joke -- you're going to have a jellyfish sandwich," Pauly said in his keynote address. "The journalists all ate it up -- not the jellyfish, the quote. It was a joke, but now it's real."
In the wake of the disastrous crash of the North Atlantic's cod stocks, the Newfoundland government is encouraging fishermen to go after jellyfish, Pauly said.
He said he recently was served some jellyfish in Thailand -- "kind of crispy, a noodlelike thing," said Pauly, who in November was chosen by Scientific American as one of the top 50 fisheries scientists in the world.
You won't find sea cucumbers in the local Safeway anytime soon, but that time is coming unless the world's ravenous appetite for fish is moderated and fish stocks are allowed to recover, he said.
"This is the trend that is spreading throughout the world," Pauly told the group. In industrialized countries, "consumers have not noticed this massive shift in marine ecosystems because trade has intensified over the years."
Just south of where the conference was held in downtown Vancouver, at
Granville Island Public Market, fish from New Zealand and Thailand are
sold routinely, he said.
The raising of fish in fish farms, known as aquaculture, does not appear to be the answer, either, Pauly said. The reason: In most cases those fish are carnivores that must be fed by catching other wild fish to be processed into fish meal. The exception may be farming fish that eat plants, which is practiced in a few countries including China, India and the Philippines, he said.
"We are really headed for trouble," said Pauly, who has worked in the Philippines, Indonesia and Germany. "There is a public dimension to this, but the public usually doesn't know about this."
Pauly, whose work has been funded in part by the Pew Charitable Trusts, a green-leaning philanthropy, is not without his critics.
"It's all right to be looking back, but I like to be looking forward," said Walter Pereyra, chairman of Seattle-based Arctic Storm Management Group, who is chairman of the National Fisheries Institute, an industry group. "There are innovations going on as we talk" to improve conservation in fisheries. Fisheries are not static, but change with ocean conditions, Pereyra said. "The challenge is to manage the fisheries within those shifts," he said.
He pointed out that a recent report by the U.S. Commission on Ocean Policy singled out the North Pacific Fishery Management Council, which oversees Alaskan fisheries, for making decisions based on conservation principles. The chairman of another study group, the Pew Oceans Commission, has also spoken favorably about the North Pacific council.
Yet conservationists have called for scrapping the system of fishery management councils, saying they are dominated by industry and its friends. They point to examples such as the collapse of groundfish off the Washington and Oregon coasts under the Pacific Fishery Management Council.
"The thing that concerns me is that we have people who want to throw everything out," Pereyra said.
Coming up is likely an intense debate about solutions to the overfishing. Pauly, like many scientists, advocates a series of so-called "marine protected areas" where no fishing is allowed and fish stocks are given a chance to recover.
The world congress continues through the week. Its theme is "Reconciling Fisheries With Conservation: The Challenge of Managing Aquatic Ecosystems." Featured tomorrow are discussions about how to make the seafood industry more environment-friendly and sustainable over many generations.
Pauly recounted how fish once overlooked as subpar have become dinner mainstays, as when fish from Australia and New Zealand known as "slimeheads" were rechristened "orange roughy" in the 1980s -- and promptly overfished. Similarly, Patagonian toothfish became "Chilean sea bass" and demand drove a thriving poaching business.
Now fishermen are starting to go after hagfish, but the development is so new that a fancy marketing name has yet to be invented, Pauly said.
What can concerned consumers do? They have a "huge role" to play by buying sustainably caught seafood, Pauly said, which they can do by printing out wallet-sized cards from the National Audubon Society and the Monterey Bay Aquarium that outline good choices. They can be found at www.thefishlist.org/FishList.pdf and www.audubon.org/campaign/lo/seafood/seafood _wallet.pdf.
Pauly also urged consumers to go further, learn about fisheries policy "and vote right," he said in an interview. "The U.S. public had a lot to do with saving the whales," Pauly said. But "our compassion has to be broader than that."
P-I reporter Robert McClure can be reached at 206-448-8092 or firstname.lastname@example.org
Georges Bank--the patch of relatively shallow ocean just off the coast of Nova Scotia, Canada--used to teem with fish. Writings from the 17th century record that boats were often surrounded by huge schools of cod, salmon, striped bass and sturgeon. Today it is a very different story. Trawlers trailing dredges the size of football fields have literally scraped the bottom clean, harvesting an entire ecosystem--including supporting substrates such as sponges--along with the catch of the day. Farther up the water column, longlines and drift nets are snagging the last sharks, swordfish and tuna. The hauls of these commercially desirable species are dwindling, and the sizes of individual fish being taken are getting smaller; a large number are even captured before they have time to mature. The phenomenon is not restricted to the North Atlantic but is occurring across the globe.
Many people are under the mistaken impression that pollution
is responsible for declines in marine species. Others may find it
hard to believe that a shortage of desirable food fish even exists,
because they still notice piles of Chilean sea bass and tuna fillets
in their local fish markets. Why is commercial fishing seen as having
little if any effect on the species that are being fished? We suspect that
this perception persists from another age, when fishing was a matter
of wresting sustenance from a hostile sea using tiny boats and simple