Steve Murawski is chief of Population Dynamics Branch at the National Marine Fishery Service in Woods Hole, Massachusetts.


The collapse of the cod fishery is probably the biggest news in the world for fisheries collapsing. Can you fill us in about the history and the consequences of the collapse?

The cod fishery, and actually by analogy the cod and haddock and pollock and other ground fish species, have undergone a tremendous change in abundance off the Northeast United States. But that’s symptomatic of a larger problem, certainly in the Northwest Atlantic. Traditionally we’ve identified up to a dozen different cod stocks in this region and they’ve all had basically the same fate over the last couple of decades. They all went through a period of heavy exploitation by distant water fleets, when the Soviet fleets and others came in the early 60s.

Both Canada and United Stated extended their jurisdiction to 200 miles and booted out the foreigners, and we’ve both gone through a period of domestic over-fishing, which have left a lot of the ground fish stocks in our regions at very low levels, with very poor expectations for short-term recovery. And I think we’re beginning to understand not only the dimensions of these problems economically, but also ecologically, which have been very dramatic.

The basis for all this is an over-fishing scenario where we’re extracting at far too high a rate given the natural productivity of these stocks. And as we start to get a handle some of these over-fishing problems and try new ways of regulating these species, we can start to see responses that give us more certainty — that underlining root cause of these declines was in fact over-fishing.

Why is cod such a prolific fish and how long do you think it will take for stocks to rebuild?

Cod — and we have to mention the haddock here in the northeast region because historically it’s been such a dominant species — have really gone through a tremendous period of boom and bust, in terms of the stock sizes and also the landings the fishermen have taken. Back at the turn century and for the first two or three decades of this century, landings of haddock really rose tremendously, as people like Clarence Birdseye came up with new ways of processing these things and filleted fish went, not only in New England but throughout the whole country.

And landings rose very quickly as new modern fishing technologies, like the auto-trawler, were introduced into our fisheries. And we saw landings going up to well over 100 million pounds of haddock per year. And that was sustainable for several decades, from the 30’s to the 1960’s. But the addition of this tremendous amount of fishing effort by the foreign fleets, plus the addition of new and improved technologies that was more able to catch the fish really sent the harvest rates of haddock and cod and other species to levels that were totally unsustainable.

The average harvest rates of those stocks in the early 1990’s were on the order of 60% per year. That means for every ten fish of adult size in the ocean six were taken out by fishing. If we assume that two of those die of natural causes that only leaves two left over to reproduce, out of that original ten, and that’s far two few. For ground fish species like cod and haddock and others, an optimal rate of harvest would be two or three out of ten per year. And that would give us a nice broad age composition of spawners; that would give us a lot of reduction in year-to-year variation because we’re leaving species in the ocean that will generally survive there.

Managers that were originally very slow to react to the high-quality scientific information that showed the declining trends in abundance — the declining trends in production of juveniles which are going to support your population two, three, four years down the road, and also this increase in the exploitation rate, the harvest rate, the fraction of the animals taken out per year — they were very slow on the switch. And because of that reason we did long-term damage to these stocks. The recovery rates of these things are slow. Generally speaking they don’t start reproducing ‘til they’re two, three, or four years old. Under natural conditions, without high harvest rate, they have life spans of fifteen or twenty years.

Cod and haddock and other species in our region are relatively long-lived, but without the effects of fishing we can see the animals living up to 15 to 20 years old, reproducing every year after the first year they start to spawn, which is age two or age three. This gives us a big buffer in these populations that are naturally subjected to a wide degree of climate variability because of the place we live in. These are good buffers for sustainable fisheries by leaving a broad age composition, and that occurs when you have low harvest rates. With harvest rates of 60% per year you cannot have a sustainable fishery on things like cod.

Please elaborate on why different age groups are important to recruitment.

For an animal like cod, where there’s a lot of year-to-year variations in the marine weather, if you will, you need to have a broad grouping — a broad distribution of age groups in the spawning population — and that’s important for two reasons. Number one, what we found in a lot of laboratory studies, in a lot of ecological studies out in the ocean, is that the older and more experienced females are better at spawning in terms of the survivorship of their young than the first-time spawners. And by fishing at a high harvest rate we concentrate all of the spawning in the first or second time spawners and the success rate is low; it’s like having a whole population of teen-age mothers, as opposed to having a good, broad distribution of everyone spawning. And these are hard-won lessons in terms of looking at fish populations and managing them.

Where do you think we stand with scientific data and research on the subject? Do you consider it still to be in its infancy and still got a long ways to go?

When you think about it and step back a little bit, we have a task that is literally of Biblical proportions — we’re trying to count how many fish are in the sea. These are large areas — in the northeast region we’re trying to look at codfish and other species over a quarter of a million square kilometers and trying to index their trends and abundance and the factors that affects their survivorship and the effects of fishery regulations. Those are difficult spatial problems. Those are difficult problems because the critters that we’re interested in hide from us — they’re under the water; they’re hard to find; they’re hard to catch. And that’s why we’ve put in sampling regimes that are trying to maximize not only our ability to go out and hunt these things down with research vessels, but also gathering every scrap of information we can from commercial fisheries, from scientifically trained observers that ride fishing boats, et cetera.

We have put together sophisticated population models that put these data sources together and try to make a unified picture of what’s happening. This is happening all over the world, where people are trying to get a handle on what’s going on in the marine environment. It’s difficult. It’s expensive; if you’re dealing with deep water and far from shore, it’s very expensive to mount the types of efforts that you need. But when you look at the value of fisheries, both in the United States and worldwide, they’re so valuable, not only in terms of economic dependency but also jobs. The amount that we’re actually spending on research is infinitesimal relative to the value, on an annual basis, to this resource.

Do you have anything to say to fishery managers worldwide on how to contend with fishermen?

These issues are not unique to fisheries management. In almost any natural resource problems we see worldwide, be it forestry or range management, these are the kinds of local level issues that we get involved in when basically we’re trying to regulate a population that’s fishing on resources that are the public’s resources. These are very understandable confrontations that we get into when we’re trying to basically make a case on the basis of the best science available that there’s a problem, and effect solutions that really change the behavior of people that are very comfortable and living in those environments and making their livings from the sea. It’s very understandable that people would be upset and question the validity of the basis for doing these things.

What we have to do is to put those into perspective, because when we go to the fishermen, we go to the public and we get their input, what we aren’t seeing, in many cases, is all the fishermen who have left the business because of poor catches, et cetera. And we don’t get a perspective on how big some of these industries could be if they’re regulated in a proper way and they’re generating the benefits that they’re capable of generating. These are understandable reactions by people that feel like they’re being scape-goated in terms of being responsible for fishery declines.

What we need to do is to act as a broader society, to try to understand the fishermen’s role in this larger issue to use their expertise in helping us design monitoring programs, and in some cases supporting them, as we’re trying to rebuild stocks and trying to get them to reduce their efforts so we can build these stocks up to sustainable levels. We need to take this on in a broader social discourse rather than just having it science versus fishermen, or science versus politicians. And I think we have taken a too narrow a view when we set this up as a series of one-in-one confrontations.

What’s your sense, speaking of just the cod and the haddock stocks, when we might expect to see them back, and secondly, if they do come back, how do you think that the fishermen are going to be able to fish again where it’s sustainable so that the whole thing doesn’t happen again?

The obvious problem is repeating the cycle of boom and bust, and that’s what we have to avoid. Economic pain is not only the fishers’, but you and I as consumers, paying high prices for low abundance fish. We don’t want to repeat that cycle again.

The computer simulations and the basic life history data that we have for so many of these species indicate that recovery times can range anywhere from five to fifteen years for the typical ground fish species, like cod and haddock and flounders, et cetera. These are all predicated on having harvest rates down to10 or 20% per year. If we can achieve those rates we can get these stocks back to where they should be in their biomass; we can broaden their age structure to what it needs to be; and we can start to generate, on an annual basis, more and more even production of baby fish, recruitment to the fisheries. But it’s all predicated on getting those exploitation rates down.

Now in the northeast, we have really gone through a kind of a catharsis in fishery management. It wasn’t until the end of 1994 that the fishery management actually started to bite in a serious way. And this was basically due to large-scale closures of very large areas in places like Georges Bank — about 6000 nautical miles were closed. And the amount of effort that each individual offshore fishing boat could generate was slashed by 50% in terms of their number of days at sea. This has worked partially, for some of the offshore species and we’re seeing some hints of recovery.

On the other hand, it’s kind of frustrating because so many of the other species have not shown any recovery; in fact exploitation rates remain high. And we have to learn from this comparison, even in our own region, what works and what doesn’t. It’s very obvious that broad regulations work in some cases and they don’t work in others, and it has to do with who’s fishing, what methods they’re using, where they’re fishing, et cetera. And we need to fine-tune this whole process so that not only certain important species are brought back, but that the entire ecosystem is brought back to a productive and sustainable level.

What would a sustainable fishery look like in our region if the stocks were to have recovered?

The sustainable fisheries are going to look a lot more different than what they’ve looked like in the last 30 years. With the lack of regulations on a lot of the industries we’ve seen basically a free-for-all, where any kinds of gear can be used, a lot of competition between gears for by-catch, and not be worried about what they’re throwing over, et cetera, which happen to be the target of some other fishery. With sustainable fisheries we’re going to have to be more cognizant of cleaning up our by-catch, to make sure that we don’t kill off the young that’s supporting another industry. So I think what we’ll see is a lot more of the spatial segregation of the fisheries where certain groups are allocated different grounds to fish, for example.

We’ll see a lot more gear development — perhaps we don’t need the biggest and widest nets and the heaviest dredges, et cetera, particularly if stocks are abundant. Because a lot of these gears were developed to catch the last fish, and when they’re abundant you don’t have to be as efficient to make a day’s pay. And so I think we’ll see down-sizing of the gear, it’ll be a lot less dirty in terms of by-catches, and we’ll see a lot more separation of the various fleets on the grounds.

You can read it in the back of National Fishermen. I mean, there are advertisements for high-quality GPS, that say the fish can’t hide anymore (our environmental friends have told us this). Even if you look at a scallop dredge — they’re wide, they’re heavy, and they’re built to be extremely quick, so that they can cover a lot of ground searching for low density. When they’re at high densities — and we just found this out by letting fishermen into closed areas out there — they can make a trip in three days with five men. They were taking up to 17 men on a sea scalloper in order to make a trip and be fishing for 14 days. When they are abundant, they’re easy to catch.

We are never going to see a return to huge employment on the harvesting sector, unless we are willing to basically tie one arm behind their back technology wise. Because technology is a substitute for labor. This is not the only industry in the United States that that happens in. We are never going to get back to the labor that we used in the low technology days. The job growth in the fishing industry is going to be on the shore side–not the harvesting side.