TRANSCRIPT - Callum Roberts
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.
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?
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?
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
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
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.
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
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.
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.
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.
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.
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?
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
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.
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
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
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.
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
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.
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.
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.
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.
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.
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.