CALLUM ROBERTS is the Professor of Marine Conservation Biology and Public Policy at Harvard University, who co-wrote (with Julie Hawkins) Fully Protected Marine Reserves: A Guide.


Why do you think we need Marine Protected Areas or marine reserves?

We need reserves because in the past we had reserves. There's nothing new about marine reserves; it's an old concept. The problem is that over the last 200 years or so of fishing we have gradually been working our way to the ends of the earth. We've been fishing all of the areas that hadn't been overly exploited up to then, and every time we exhausted a local stock of fish we would move on to something else. There was always something else left.

What's happening now, though, is that we've reached the end of those resources. If you look at the coast of California here there are exquisitely detailed seafloor maps that are produced by the Geological Survey. Those maps, together with satellite positioning technology and sonar technology, which has been developed out of military applications, allow fishers to pinpoint where the stocks are, they can put their nets down with much less risk of them being caught on rocks than they used to be able to do.

So now we fish out every one of those last remaining refuges that formerly were an important part of the supply side of fisheries. Those natural refuges that existed when we didn't fish everywhere were very important in sustaining fisheries because they provided the offspring that were necessary to replenish fishing grounds. So as long as there were big spawning stocks of adult fishes around that were inaccessible to fishing, then the fishery production would remain very high.

But as we've eroded away those refuges, we've also seen a general decline in fish production and what we have to do today is to put those refuges back. We have to create them artificially.

What exactly is a fully protected marine reserve?

Marine protected area broadly is an area that is protected from some form of activity. Fully protected marine reserves are a subset; they are a much more protected subset of marine protected areas as a whole. They're closed to ALL fishing, not just to a few kinds of fishing. And they're also protected from other kinds of extractive use, like mining or oil and gas exploitation.

But they also have to be protected from damaging activities, like dumping. And so within a fully protected marine reserve we are trying to remove all the harmful things that people do to the ocean environment.

What percentage of the oceans is fully protected today?

We're still right at the beginning of the protection of the oceans. We have something like half a percent or less of the seas within marine protected areas broadly, but if we look at what's protected from all fishing there's something like 1/10,000 of the surface of the seas falls into no-fishing zones. And even worse, of that perhaps as much as half of it is enforced.

How do fully protected marine reserves compare to a protected national park?

Marine reserves are both like terrestrial protected areas and different from them. Both kinds of protected areas aim to protect the animals and plants, which are within them. Unlike terrestrial protected areas, though, marine reserves can potentially support an extractive industry. And the reason that they can do this is because fish stocks reproducing inside the reserves produce an offspring, which are transported by ocean currents outside and into fishing grounds.

And so you can have conservation and you can have economic productivity. You can put the two together; fishing and conservation are fully compatible.

How are fully protected marine reserves like having money in the bank?

Reserves are like money in the bank because what they do is to protect the spawning stocks of fish. And as those spawning stocks grow in size so do the deposit in your bank account that's larger. And that deposit yields interest in the way of eggs and larvae that are produced by the fish inside the reserves and those are transported into fishing grounds so replenishing the fishery.

But what would you say to people who are afraid that by creating marine reserves you are taking away their fishing grounds?

When you create a fully protected reserve you take some of the fishing grounds away from people. And one of the ways that that taking away is offset is by spillover across the boundaries of the reserve. As the stocks build up inside the protected area so they start to feed fish into the surrounding fishing grounds. They emigrate from the reserve into the fishing areas where they can be caught.

One thing that we have seen around the world, as well-established reserves have been in place for longer and longer, is that people start to change their fishing patterns. They start to preferentially close to the reserve boundaries and they are benefiting from higher catches.

There's one example in the Mombassa Marine National Park in East Africa, the catch is 25% higher closer to the boundary of the reserve than they are further away. And the fishing sites closer to the reserve are so much desired that there's an agreement among the fishers that the most senior of them have preference of access to the reserve boundary locations.

We've seen fishers changing their behavior and fishing closer to reserves in many parts of the world -- in Chile, New Zealand, in the Philippines, in the Caribbean, even in Georges Bank off the east coast of the United States when areas were closed to scallop fishing, the scallop vessels started to fish very close to the reserve boundaries within only a few years of them being protected. What we're seeing is that fishers are sampling their environment and finding the places that are good for catching fish. And those places are, not surprisingly, close to reserves because the fish stocks are bigger in those areas.

Can you speak to the fact that there is absolute scientific evidence that there is a spillover effect?

There are a lot of people who say that the science is not sufficient yet to embark on a program of establishing marine reserves. But we know that marine reserves work under a very wide range of conditions. They've worked under a range of different environments, from temperate to tropical; even the Polar Regions have been tested now.

They've also worked across a range of fisheries. They've produced benefits to small-scale fisheries; they've produced benefits to large-scale industrial fisheries. The success of reserves is not contingent upon a geographical region or to kinds of fish that you are trying to protect or the habitats that you're trying to protect.

Because we have this body of experience now, which is very, very large and it's detailed, we know that we can set up reserves that will work by just following a few straightforward principles. It's possible to design them for any circumstances and to expect to see benefits within only a few years.

What we can be very clear about is that if we don't set up reserves we will see continuing declines in fish stocks. The tools that we use to manage fisheries today don't work. We need to provide alternatives that are robust, which treat the ocean environment as an ecosystem, rather than trying to pick out individual species and pretend that they can be managed separately. We need tools that build insurance into the management process so that there are still fish stocks remaining if we make mistakes. And if we have fish stocks after we make mistakes we can expect to see recovery of fishery productivity much more frequently.

So reserves are a necessary part of fishery management today. To respond to the criticisms that there isn't enough science, there is. There's a great deal more than we found out about reserves recently. More than a hundred studies show that they work well in many different parts of the world.

If we take the lessons from those studies we can design effective reserves anywhere that they are needed.

How do the densities of fish inside reserves compare to the densities of fish outside reserves?

One of the pioneering marine reserves in the world was the Leigh Marine Reserve off the north island of New Zealand. Although this reserve is only 5 square kilometers in size, it's been incredibly important to our understanding how they work. Within a few years of being established and protected from fishing there were dramatic changes that began to occur inside it. Fish stocks began to build up, the uh- densities of spiny lobster began to build up, and fishers started to recognize that this- this was a place that they could catch more and they started to fish the line around the reserve.

This success has continued over the years and now 24 years after the reserve was established densities of exploited snapper species are nearly 40 times greater inside the reserve than outside. Densities of spiny lobsters have been increasing by 5% per year and those benefits have been spilling over to fisheries surrounding the area.

The Leigh Reserve has been very important to us because it told us, number one that we're having a major impact on ocean life through our fishing activities. That was a surprise. It's been very important because it showed us that we can reverse that decline if we protect an area from fishing; it's possible to get things back.

And the third thing that it's done is to show that we can rally public support around reserves. When they first suggested the Leigh Reserve in New Zealand it was dismissed by the fishing industry, by the government, biologists, decision-makers didn't think it would work and many people just didn't think there was a need for it.

Those attitudes have changed now. New Zealand has embarked upon a program of creating a national system of marine reserves because it knows that they are necessary for the productivity of the fisheries and for conservation.

Can you speak about the biological importance of having larger and older fish and what that means in terms of dispersal and in the interest of fishermen?

It's important to have older, larger fish in a population. One thing that's clear from the ocean environment today is we are seeing long-term oscillations in conditions. Fish cannot reproduce as effectively throughout all phases of those ocean conditions. So what we find is that there are a period of good years where they produce offspring that survive well and there are long stretches of bad years when they produce very few that survive.

In order for a population to persist over the long-term, you need to have long-lived fish that can get through those periods of lean years and are still left to reproduce when the good years return. What fishing does is it compresses the age structure of the population. For example, if we didn't fish cod individuals would live for 20 or 30 years and would reproduce repeatedly over long life spans. This is enough to get them through these periods of changing conditions.

Today, in exploited stocks there are perhaps one or two reproductively active age classes. All of the rest are immature. And if you look at the number of mature fish as proportionate to populations there are almost no mature cod there to reproduce. This means when you get successive years of bad conditions it can easily cause a collapse of cod stock.

If we use marine reserves we can start to rebuild that age structure of a fish population. We can give it back the resilience it needs to rebound after periods of poor oceanic conditions, so that there are still fish out there to reproduce when times get better.

Can you put the issue of marine reserves in the context of a longer time period?

The oceans today are very different than the oceans of 4 or 500 years ago. The early accounts from ocean adventurers, the explorers who sailed around the world discovering new lands, are so fantastical to us today that we don't believe them. There are tales of rafts of turtles so big off of the Brazilian coast that they look like islands.

In eastern Australia early eyewitness accounts suggest that there were migrating herds of dugongs, sea cows, which were 3 to 4 miles long and half a mile wide. Looking at the tiny population there is there today, of a few thousand individuals, it's hard to imagine the millions of sea cows that used to exist on the eastern Australian coast.

Almost anywhere in the oceans that you look today the ecosystem has been dramatically transformed. There has been a massive loss of large vertebrate populations. Things like whales, porpoises, turtles, sea cows are gone. The role that they've played in that ecosystem has gone with them. It's hard to imagine now the giant schools of cod hunting off the east coast of Canada and the USA that were discovered when explorers first found the new colony. And yet they were part of the ecosystem, which was extremely productive, and in which people could seemingly take endless fish from.

What we see today is very different from that, and it's been different from those primordial conditions for a long time. The imprint of humanity is large but it was large a hundred years ago. Today's generation fail to appreciate that we've transformed the marine ecosystem before they even looked at them for the first time. What we see today lacks the historical perspective.

If we were able to match up the ecosystems of 200 years ago with those of today, our appreciation of the decline of ocean life would be very much more sharp. We would perhaps be thinking about doing something about it more urgently. Taking the long-term view gives you an understanding of how things have been diminished over the years. What marine reserves can do is to potentially start rebuilding that former productivity.

We could have those populations of large vertebrates, like schools of swordfish, giant tunas turtles back. But we have to commit to protecting a large faction of the seas from fishing. Doing that wouldn't hurt the fishing industry because reserves would provide the fishery at the same time as they are serving the stocks.

Fishermen are scared of marine reserves because they think that when you have one, then they will eventually be everywhere and there won't be any more places left to fish. What would you say to them?

What the science about marine reserves says is that we need to create reserves in networks if they are going to sustain populations over the long term. We can mix conservation and fishery objectives in creating a network of reserves which consist of small units that are spread around a large areas of coast.

And one thing that we need to do is ensure that the reserves don't hurt the livelihood of the local fishers too much. Each time you create a reserve you displace the fishers from their traditional fishing grounds. If you create a reserve that's too big then you'll create winners and losers. The winners will be the people close to the edges who are getting the spillover from the reserve. The losers will be the people in the middle who have to travel much further to reach their fishing grounds.

Why exactly is the system of small reserves so important?

In order to work, a marine reserve has to support some sustaining populations of the animals and plants inside it. We know that marine species disperse over large distances. If we were to create a reserve that was large enough to encompass those dispersal distances so the populations could replenish locally, they would be too large to be acceptable to society.

But there's an alternative solution that we can do to allow our stocks to persist in reserves, and that is to network them so that they exchange animals and plants between them. And so a population can persist because it's receiving inputs from other reserves. At the same it's receiving inputs from other reserves it's exporting to surrounding fishing grounds. So you can create a population that's persistent on a large scale that survives for long periods by creating a network of small reserves rather than needing to have a single large area.

How much of our total oceans need to be protected?

Much of what we know about marine reserves comes from very small, protected areas -- one or a few square kilometers in size. But we know if we're going to make a difference to fisheries we need to scale up from that. Our best understanding at the moment is that we need to protect something like 20, 30, even 40% of the oceans from fishing to gain the maximum benefits from them.

This concerns the fishing industry people a great deal because they think that this is going to take away from their livelihoods. The fact is that this can be expected to put the fishing industry in a much more sustainable footing. Large reserves are necessary to protect any of the species that they depend on, animals that move across considerable distances. But we can offer them protection by creating reserves in relatively small units, a few to a few tens of kilometers across. Such areas can spread the benefits to the fishery around at the same time offering what we need in the way of ecosystem protection.

People who go out fishing often worry that we are going to fill the oceans with marine reserves and so impact on their livelihoods. If reserves don't produce the predicted benefits to the fishing industry, then we won't create more. I think that the economic rationale for establishing reserves is a powerful one. If it turns out that we didn't see the expected yields, then we would end up having a much smaller fractions of the oceans protected for conservation purposes.

So I think the fishing industry can be reassured that we're not going to establish networks of marine reserves all at once. We're going to build them incrementally. And as long as there's still a benefit to be had by adding more reserves to a network, then we'll do so. But when the benefits are outweighed by the costs, then network establishment will be complete.

In what ways are marine reserves beneficial to protecting the invertebrates, like corals and other things that take centuries to grow, and what is the importance of protecting them?

Over the last two centuries the range of fishing has been expanding. And we've been fishing farther and farther a field, exploiting new populations. And so we're able to sustain the productivity of fisheries by moving on from one thing to the next. Today we're developing technology, which are allowing us to fish much deeper than we ever could in the past.

Today's fishing gears can reach depths of 2 kilometers. The continental shelf areas, the shallow seas, have been damaged by trawling in the historical past. Much of the damage in the North Sea was done in the late 19th century. But today we're opening up a new frontier of the oceans to fishing -- deep seas. What we're finding is that some of these communities are incredibly diverse, incredibly fragile and urgently need protection. We're seeing communities for the first time, which have been destroyed in only a few years of fishing.

I've seen images of the tops of seamounts, which would make my blood run cold -- before and after the impact of fishing. Before they're luxuriant forests of invertebrates filled with fish; afterwards they've been stripped to bare rock by the effects of trawling gears.

Nowhere is the analogy of trawling being like clear-cutting a forest more appropriate than in the deep sea. These are areas where these invertebrate communities, the forests of the seafloor, have been developing for thousands of years. Trawling them today is like clear-cutting the ancient forests of the Pacific Northwest. We are taking the heart out of these ecosystems faster than we can describe what they consist of.

Marine reserves can be as useful in deep-sea areas and offshore areas as they can in the near-shore areas that we think about protecting most often today. It's often not appreciated how important it is to protect the deep sea from fishing. Few people understand how deep fishing penetrates, but also they don't understand how fragile deep-sea ecosystems are. We have a tool here that can offer protection to the deep-sea areas; we need to apply it.

Speak to us about migratory species and marine reserves.

Marine reserves will work best at protecting things that stay put. Fish that don't move around very much will be sheltered from the effects of fishing inside the boundaries of the reserve. This has led to many people dismissing the use of reserves as a tool for protecting migratory species -- animals that move long distances, hundreds or perhaps thousands of kilometers throughout the year.

But reserves can work for them, too. In fact fishery agencies already use protected areas to help look after stocks of migratory species. They protect them in places where they're most vulnerable -- the nursery areas, or the spawning aggregation sites. Usually these are temporary closures but we could expand them to be fully protected from fishing, offering even greater level of protection.

The fishing industry has traditionally exploited migratory species by concentrating effort on places where they are most vulnerable to capture -- places where they are aggregated in space and time. And if we target marine reserves to these migration bottlenecks, theses places where they are much more vulnerable to capture, then we can help offer them the protection that they need.

But reserves are not the only answer for species like that. They are necessary but not sufficient for their protection. We need to also offer other more conventional management tools, restraining fishing effort outside the marine reserves.