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Marine reserves: the best option for our oceans?
Elliott A Norse
Marine Conservation Biology Institute,
Redmond, WA, USA
Ideas and epidemics have intriguing similarities. Some die out quickly, while others
linger but never become prevalent. Still others with
the right combination of attributes at the right time
experience explosive growth, with dramatic effects.
The idea of protecting places in the sea is in a rapid
growth phase. In contrast with temporary fishery closures, marine protected areas (MPAs) are permanently
protected from at least one threat. Marine reserves are
MPAs that are protected from all preventable threats.
National parks on land date from 1872 (Yellowstone), but intentional protection of places in the sea
is more recent. Fort Jefferson National Monument in
Florida, which contains important coral reefs, was designated in 1935, yet progress was still gastropodal
when I started working on MPAs in 1978. Also, most
MPAs were designated with little scientific basis.
Pollution, especially oil pollution, was seen as the
biggest threat, probably because oil floats, thereby
making its effects more visible. Locations were chosen
mainly because somebody liked them enough to work
to secure nominal protection. Such MPAs could
accomplish little beyond raising consciousness about
what would soon be called biological diversity, but an
outbreak of new thinking occurred in the late 1990s.
By the time of the first Symposium on Marine
Conservation Biology in Victoria, British Columbia, in
1997, nearly all the buzz concerned marine reserves.
What had happened?
Before then, the prevailing science dealing with
human impacts on marine organisms – fisheries biology – had generally treated the sea as being uniform.
But new oceanographic tools, from satellite images of
ocean productivity patterns to remotely operated vehicle photographs of benthic ecosystems, showed that
the sea is heterogeneous and dynamic. Ecologists’ realization that metapopulation and source–sink dynamics
apply to species with planktonic larvae allowed us to
better understand dispersal, recruitment, post-recruitment survivorship and reproduction – processes that,
together, produce existing patterns. An obvious conclusion is that some places in the sea are particularly
important.
Then, in 1998, 1605 marine scientists and conservation biologists from 70 nations released Troubled
waters: a call for action (www.mcbi.org/AboutUs/
TroubledWaters.pdf), an unprecedented statement
that the sea is imperiled, that fishing is a major cause,
© The Ecological Society of America
and that a sizeable portion of the sea should be protected from threats. A landmark study by Pauly et al.
(1998) showed that fishing greatly reduces the average
trophic level of fish catches worldwide. Watling and
Norse (1998) showed that trawling profoundly disturbs
the seafloor on a vast scale. Jackson et al. (2001) and
Myers and Worm (2003) confirmed that fishing
threatens biodiversity and healthy fisheries on a global
scale.
Clearly, prevailing management hasn’t worked. In
1999, therefore, the National Center for Ecological
Analysis and Synthesis (NCEAS) began a study to
advance the theory of marine reserve design and to
synthesize data on the performance of existing reserves
(Lubchenco et al. 2003). The participating scientists
concluded that reserves trigger lasting, often rapid
increases in abundance, diversity, and productivity of
marine organisms, and that reserve size matters.
However, even small reserves have positive effects,
reserve networks achieve benefits greater than isolated
reserves, and full protection is necessary to achieve
these benefits. Furthermore, in the few studies that
examined effects outside reserves, size and abundance
of exploited species increased, thanks in part to larval
spillover. The NCEAS working group concluded that
existing scientific information justifies immediate
application of marine reserves as a central management tool. Superimposed on findings by the National
Research Council panel on MPAs (Houde 2001), the
NCEAS study provided a compelling case for establishing marine reserve networks.
The growing scientific consensus has evoked diverse
responses. In 2000, President Clinton issued Executive
Order 13158, calling for a national system of MPAs
and the Bush administration is now implementing it,
albeit slowly. Conservation organizations that had
intermittently supported less protective MPAs were
immediately energized, shifting their focus to fully protected marine reserves. Lobbyists for some commercial
fishing interests oppose reserves, maintaining that the
science is inconclusive. Hard-liners in the recreational
fishing community either oppose reserves or argue that
sportfishers (numbering perhaps 16 000 000 in the US)
have such small impact that sportfishing should be
allowed in reserves. In a move reminiscent of “scientific debates” on pesticides, cigarette smoking, and
global warming, a sportfishing trade association commissioned a fisheries biologist to issue a critique of
reserve theory (Shipp 2002), which was rebutted by
ecologists who study reserves (Carr et al. 2002). In
2003, the blue-ribbon Pew Oceans Commission
(including fishermen, environmentalists, and scien-
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Marine reserves: the best option for our oceans?
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tists) recommended the establishment of a national
system of marine reserves.
Protected areas have become the last redoubts for
many terrestrial species. In the sea they probably have
the additional benefit of replenishing depleted populations outside their boundaries. Reserves cannot solve
all marine conservation problems, and are likely to
work best when integrated with temporary fishery closures, traditional fishery management methods, and
buffer zones. Given the urgent need to protect and
recover marine biodiversity, the case for reserves is so
strong that it seems imprudent to wait until implacable
opponents of marine conservation are convinced by
the evidence.
References
Carr M, Dayton P, Gaines S, et al. 2002. Comments on ASA
report entitled “No take marine [protected areas (nMPAs) as a
fishery management tool, a pragmatic perspective” by Robert
L Shipp. www.compassonline.org/rebuttal_to_ASA.pdf. Viewed Oct 14 2003.
Houde E. 2001. Marine protected areas: tools for sustaining
ocean ecosystems. Washington, DC: National Academy
Press.
Jackson JB, Kirby MX, Berger WH, et al. 2001. Historical overfishing and the recent collapse of coastal ecosystems. Science
293: 1589–91.
Lubchenco J, Palumbi SR, Gaines SD, and Andleman S. 2003.
Plugging a hole in the ocean: the emerging science of
marine reserves. Ecol Appl 13 (Suppl): S3–S7.
Myers RA and Worm B. 2003. Rapid worldwide depletion of
predatory fish communities. Nature 423: 280–83.
Pauly DV, Christensen V, Dalsgaard J, et al. 1998. Fishing down
marine food webs. Science 279: 860–63.
Shipp RL. 2002. No Take Marine Protected Areas (nMPAs) as
a fishery management tool, a pragmatic perspective. A
report to the FishAmerica Foundation. www.asafishing.org/
images/gais_shipp.pdf. Viewed Oct 8 2003.
Watling L and Norse EA. 1998. Disturbance of the seabed by
mobile fishing gear: a comparison to forest clearcutting.
Conserv Biol 12: 1180–97.
Churchill B Grimes and
Stephen Ralston
National Marine Fisheries Service, Santa
Cruz, CA,USA
In his opening statement Norse writes,
“Ideas and epidemics have intriguing similarities.” So too, we believe, do epidemics and
the sudden advocacy of (MPAs) as a panacea
for the ocean’s ills. Epidemic is exactly how
we would describe the onslaught of information supporting the use of MPAs to save the
imperiled seas from, among other things, the adverse effects
of fishing (NRC 2001; Lubchenco et al. 2003). While we
don’t quibble with the assertion that, globally, the oceans
are in dire need of increased protection, we would argue
that some of the touted benefits of MPAs are controversial
and have not been conclusively demonstrated.
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Unfortunately, the debate concerning the use of MPAs
to achieve sustainable fisheries has become polarized, and
is rife with scientific advocacy and oversimplification
(Lubchenco et al. 2003; Shipp 2003). Most egregious to
us is the naiveté of some people regarding the accomplishments of fishery science. For example, Norse states
that prior to 1997, “fisheries biology…had generally
treated the sea as being uniform”. Such a statement, at
best, ignores the rich and long-standing contributions of
fisheries science to our understanding of ocean ecosystems (Hjort, Cushing, Harden-Jones, and Sinclair) and,
at worst, subliminally casts blame on fisheries science for
bringing us to our current state of affairs. In fact, 50 years
ago two pre-eminent fisheries biologists, Ray Beverton
and Sidney Holt, modeled the impact of spatial closures
on fishery yields (Guénette et al. 1998). As to the quality
of government fishery science, several National Research
Council studies (eg NRC 2002) concluded that US
National Marine Fisheries Service (NMFS) stock assessment techniques are second to none among government
fishery management agencies worldwide.
The justification that is most often cited for establishing domestic MPAs is that traditional fisheries management in the US is a failure. However, this is ill-informed.
The present low levels of many fish stocks reflect poor
management decisions made many years ago. A closer
look at current exploitation rates reveals that current
management is doing far better. Although many fisheries
(eg cod in the northwest Atlantic and certain rockfish
stocks along the west coast of the US) are in severe
decline, many others, such as king mackerel in the Gulf
of Mexico, summer and yellowtail flounder, Atlantic
mackerel, and sea scallop along the US Atlantic coast,
are at sustainable levels. In fact, of the 283 (25%) of 905
fish stocks managed by NMFS for which the status is
known, only 15% are overfished and 39% are fished at or
near their long-term potential yield (NRC 2002).
Moreover, many US fisheries are already managed under
severe spatial management regimes; for example, virtually
the entire continental shelf of the west coast is presently
closed to groundfishing.
While we are aware of evidence of the conservation
benefits of biodiversity enhancement, population growth,
attenuated size/age composition, and habitat recovery
inside reserve boundaries, as well as adult spillover outside reserve boundaries, there are other critical scientific
issues that are poorly understood. One simplistic generalization being touted by MPA advocates is that, at a minimum, 20% of a species’ habitat needs to be protected to
realize the benefits of an MPA (Agardy 2003). This figure
is apparently based upon theoretical results showing that
when fishing mortality is excessive, overall fishery yields
could be enhanced by substantial area closures. However,
many studies also show that traditional fishery management controls on fishing effort correspond directly to area
controls, and that it is possible to manage fisheries optimally just using effort controls (Mangel 1998; Hastings
© The Ecological Society of America
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Marine reserves: the best option for our oceans?
and Botsford 1999), which has been the general paradigm
practiced within the US. Moreover, the claim has been
frequently made that MPAs will promote sustainable fisheries and enhance fishery yields (Nowlis and Roberts
1998), but density-dependent theory tells us that percapita production is lowest at carrying capacity (ie in the
absence of fishing), and that compensation at lower population levels produces a surplus that can be sustainably
harvested. How will overall stock dynamics (eg potential
yield, spawning stock-recruitment relations, spawning
biomass targets and rebuilding trajectories) be affected by
declining compensation within reserve boundaries, and
how will the time-delayed impact of MPAs affect ecological and stock dynamics both inside and outside the
reserve? Equally important, how will fishing effort displaced by MPAs affect catch rates, yields, and habitats
outside reserve boundaries?
We are certainly not opposed to the use of MPAs to
attain the conservation benefits pointed out above to
provide insurance against errors in traditional fishery
management, and as natural research and reference areas.
However, we believe there are important unresolved
issues that need to be answered before claims that MPAs
will improve fishery management can be fully accepted.
In addition, managing fisheries with MPAs needs to be
placed in the context of existing management controls,
which requires a case-by-case consideration of all available options.
References
Agardy T, Bridgewater P, Crosby MP, et al. 2003. Dangerous targets? Unresolved issues and ideological clashes around marine
protected areas. Aquatic Conserv 13: 353–67.
Guénette S, Lauck T, and Clark C. 1998. Marine reserves: from
Beverton and Holt to the present. Rev Fish Bio Fisher 8:
251–72.
Hastings A and Botsford LW. 1999. Equivalence in yield from
marine reserves and traditional fisheries management. Science
284: 1537–38.
Lubchenco J, Palumbi SR, Gaines SD, and Andleman S. 2003.
Plugging a hole in the ocean: the emerging science of marine
reserves. Ecol Appl 13 (Suppl): S3–S7.
Mangel M. 1998. No-take areas for sustainability of harvested
species and a conservation invariant for marine reserves. Ecol
Lett 1: 87–90.
National Research Council (NRC). 2002. Science and its role in
the National Marine Fisheries Service. Washington, DC:
National Academy Press.
Nowlis JS and Roberts CM. 1998. Fisheries benefits and optimal
design of marine reserves. US Fish Bull 97: 604–16.
Ray Hilborn
School of Aquatic and Fishery Sciences,
University of Washington, Seattle, WA,
USA
Amidst the concerted rush of ecologists to
push for the establishment of networks of MPAs, we need
to brush off a little old-fashioned scientific skepticism and
look carefully at the potential benefits and costs of MPA
© The Ecological Society of America
networks. As a conservation tool, MPAs move fishing
effort out of some areas and shift it to others. It is not too
surprising that abundance increases where fewer fish are
removed, but the displaced fishing effort goes elsewhere.
We need to ask whether the biodiversity benefits inside
the protected area are more valuable than the biodiversity
costs of additional fishing pressure outside. Once we realize that MPAs are effort-shifting programs, we recognize
that the comparison of abundance inside and outside protected areas is flawed; the benefits estimated by comparing
abundance inside and outside reserves, or before and after
reserves are established (Halpern and Warner 2002) will
be exaggerated.
Most MPA literature begins with a litany of the failures
of fisheries management and MPA advocates have often
used the fisheries management benefits of MPAs as a
major selling point. MPAs can only benefit the yield of
managed species if the species is overfished and if the
movement rate of the spawning population is low enough
relative to the size of the MPAs that spawning populations can build up inside them. Shipp (2002) points out
that these two circumstances are rather unusual. Only
30% of the major fisheries in the US are classified as
overfished, and for most of those species the movement of
adults is great enough that only large MPAs would have
much effect. Since current yield of US fisheries is over
80% of its potential yield (Hilborn et al. in press), there is
little room for MPAs to increase fish yields.
For MPAs to be effective in increasing sustainable yield
for a species, the sizes of the protected areas must be carefully matched to the movement of that species. If the
MPAs are very large relative to movement, then yield is
reduced because the fish are locked up. If the MPAs are
too small, then there is insignificant buildup inside the
reserves. No pattern of MPAs will be optimal, or even
suitable, for all species; having different areas closed for
different species would provide better yield and conservation benefits than blanket MPAs. Such areas are steps forward in the management of fisheries because they recognize the need for spatial management, but they are very
blunt tools and we can do much better than one-size-fitsall networks if our objective is to maximize sustainable
yield. Rather than broadly improving fisheries yields, a
network of MPAs might improve yield in a few instances.
MPAs must be integrated into the fisheries management
system. It is easily demonstrated that adding an MPA to a
fishery regulated by catch quotas will generally require that
the quota be reduced. While advocates argue that MPAs
will increase fish yields (PISCO 2002), they rarely, if ever,
do the quantitative work necessary to determine how regulations will need to change when an MPA is put in place.
Despite my skepticism, I believe that the establishment
of MPAs is indeed a good idea, and when done with very
specific objectives can benefit specific fisheries. I have no
doubt that the abundance of many species will be higher
in protected areas, and would like to see more marine
areas protected in the same way that I wish more of the
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Marine reserves: the best option for our oceans?
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terrestrial habitat had been protected in parks.
I do see MPAs having an important role in fisheries
management. First, in some places it may be possible to
enforce protected areas where other forms of fisheries regulation are not practical. Second, in the US and other
intensively managed countries, the vast majority of
species are not regulated. Several hundred species are
caught in the west coast trawl fishery, yet fewer than 20
are assessed (Hilborn et al. in press.). The vast majority of
species are generally not of major commercial interest, but
conservation concern for all species is currently driving
management regulations; the west coast fishery is largely
closed at present to protect several species classified as
overfished. I see that MPA networks can be established to
protect the biodiversity of marine communities, so that
exploitation of the commercially important and healthy
species can take place outside reserves. Essentially, the
reserves would guarantee the protection of overfished or
unassessed species. This will probably mean less (not
more) yield of the healthy species compared to their
potential yield, but it would allow commercial exploitation to continue in some places while providing for protection of a broad range of species.
References
Halpern BS and Warner RR. 2002. Marine reserves have rapid and
lasting effects. Ecol Lett 5: 361–66.
Hilborn R, Punt AE, and Orensanz J. Beyond band-aids in fisheries
management: fixing world fisheries. Bull Marine Science. In
press.
PISCO (Partnership for the Interdisciplinary Study of the Coastal
Oceans). 2002. The science of marine reserves (video and
booklet). www.piscoweb.org.
Shipp RL. 2002. No Take Marine Protected Areas (nMPAs) as a
fishery management tool, a pragmatic perspective. A report to
the FishAmerica Foundation. www.asafishing.org/images/gais_
shipp.pdf. Viewed Oct 8 2003.
Juan Carlos Castilla
Centro de Estudios Avanzados en Ecología
& Biodiversidad, Santiago, Chile
Elliot Norse’s depiction of MPAs as the
saviors of our marine environment does
not ring true for the situation here in Chile. Perhaps this
is because his ideas were formulated with the US in mind
rather than an international perspective. However, even
within the context of the US, Norse’s views seem too narrow. Most troubling is the unquestioning advocacy of
MPAs as “the central management tool” with “full protection necessary”. One can come to a different conclusion if one begins with different assumptions, definitions,
and goals for conservation. The conclusions reached
regarding MPAs depend to a large extent on how we
begin with definitions of biodiversity and conservation.
The oceans face serious conservation problems, with the
state of the world’s fisheries indicating resource overexploitations and a failure of existing management tools
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(Botsford et al. 1997). It follows that a new set of policies
needs to be implemented to improve the situation.
However, the establishment of marine reserve networks is
just one of those tools. We should not fool ourselves into
believing that by simply protecting or conserving coastal
and open sea sites from “all preventable threats”, problems
will be solved. The situation is more complex, and the regulation of fishing effort is one critical aspect of it.
Furthermore, scientists and agencies cannot agree on
the exact meaning of “marine conservation”, and the role
of MPAs. The US National Research Council (2001) suggested that one of the main priorities for MPAs was to
“protect biodiversity”. It has been argued that “if society
were forced to await the satisfaction of all economic interests before protecting their resources, it is improbable that
much protection would ever occur, and the resources supporting the economic concerns would continue their collapse” (Sala et al. 2003). On the other hand, Sanchiro et
al. (2003) have argued that MPA analysis should strive to
better represent the complex ecological, sociocultural, and
economic dimensions by including variables that are sufficient to capture the range of human activity (O’Connor et
al. in press). These disagreements can go on forever. There
are many possible options and I believe the best one is to
first clarify the concept of biodiversity and then encourage
the direct participation of fishermen, users, organizations,
and governments.
The UN Convention on Biological Biodiversity defines
biodiversity as “the variability among living organisms
from all sources including, inter alia, terrestrial, marine
and other aquatic ecosystems, and the ecological complexes of which they are part; this includes diversity
within species, between species, and of ecosystems”.
Clearly, biodiversity includes not just the species that
reside in an area, but also functioning ecosystems; biodiversity can be seen as a structural feature of ecosystems.
Therefore, a comprehensive approach to marine problems should embrace an ecosystem services perspective,
rather than focus mainly on species richness. Ecosystem
services are those conditions and processes through
which natural ecosystems, and the species that comprise
them, sustain and fulfill human life; they maintain biodiversity and the production of goods (Daily 1997); and
represent the benefits human populations derive, directly
or indirectly, from ecosystem functions (Costanza et al.
1997). This does not mean that society should await the
resolution of all economic concerns before protecting its
resources. We must act immediately, using rational, comprehensive, and innovative approaches that include
humans as part of ecosystems. In fact, the first preamble
clause of the Convention on Biodiversity refers to “the
intrinsic value of Biological Diversity”, but also to “the
ecological, genetic, social, economic, scientific, educational, cultural, recreational, and aesthetic values”.
Ecosystem services can be classified into: provisioning (eg
food, genetic resources), regulating (eg water, detoxification control), cultural (eg identity, educational values)
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Marine reserves: the best option for our oceans?
and supporting (eg primary production, provision of habitats) (MEA in press).
Thus we need to integrate into the concept of “marine
reserve networking” a richer set of objectives than simply
sequestering species in no-take areas. I suggest that marine
management and marine conservation be melted into one
enterprise. For example, artisanal fisheries are important
components of coastal ecosystems throughout South
America; marine conservation must include these fishing
communities and the economic and production services
they rely on, as well as species richness. In Chile, a mix of
local, community-based management units and marine protected areas (Castilla 2000) promises the greatest hope for
the marine environment. In general, we cannot expect any
approach or solution to work in all countries. We need
adaptive and multi-approach plans with strategies adapted
to countries, states, regions, governance, and idiosyncrasies.
References
Botsford LW, Castilla JC, and Petersen CH. 1997. The management of fisheries and marine ecosystems. Science 277: 509–15.
Castilla JC. 2000. Roles of experimental ecology in coastal management and conservation. J Exp Mar Biol Ecol 250: 3–21.
Costanza R, D’Arge R, de Groot R, et al. 1997. The value of the
world’s ecosystems services and natural capital. Nature 387:
253–60.
Daily GC. 1997. Introduction: what are ecosystems services? In:
Daily GC (Ed). Nature’s services: societal, dependence on natural ecosystems. Washington DC: Island Press.
MEA (Millennium Ecosystem Assessment). People and ecosystems: a framework for assessment and action. Washington, DC:
Island Press. In press.
O’Connors CM, Marvier M, and Kareiva P. Biological vs social,
economic and political priority-setting in conservation. Ecol
Lett. In press.
Salas E, Aburto-Oropeza O, Paredes G, et al. 2003. Response to
“Modeling marine protected areas”. Science 301: 48–49.
Shanchirico JN, Stoflee R, Broad K, and Taluane-McManus L.
2003. Modeling marine protected areas. Science 301: 47–48.
Stephen R Palumbi
Biological Sciences, Stanford University,
Hopkins Marine Station, Pacific Grove,
CA, USA
Suppose there was no overfishing – that all
fished species were perfectly managed to yield a sustained
take – would there still be a need for any fully protected
marine reserves? On the surface, this seems, perhaps, a
foolish question, because reserves protect against the
local damage caused by overfishing. But even in an imaginary world where fished species were not disappearing,
there would still be powerful reasons to create reserves.
Impacts from exploitation can be felt even in the
absence of overfishing. Fisheries species can be considered healthy even though they persist at only one-third of
their former abundance, and many important fishing
species are far rarer, at about 10% of historic levels.
Reducing species to these levels can still yield sustainable
fisheries, but such reductions in abundance can have dra© The Ecological Society of America
matic impacts on marine ecosystems. Reserves can help
to buffer these impacts.
Three aspects of fishing can generate impacts, even if
fished species are sustainable. First, sustainable mechanized fishing can disturb bottom habitats, removing biological architecture species such as oyster reefs (Brooks
1891), dredging seabed structures that provide juvenile
protection, or disturbing spawning grounds. Because even
low intensity dredging can dramatically alter the seafloor
for years (Peterson and Estes 2001), reserves play a key
role by creating areas free of this impact.
Second, removal of a large part of a population – even
when no physical habitat is disturbed – can result in
extreme disruption of an ecosystem. This disruption is
called ecological overfishing (Palumbi 2003) and an
example is found in lobster harvesting. Low numbers of
lobsters result in sea urchin booms and loss of kelp beds in
New Zealand and California (Babcock et al. 1999; Laferty
unpublished). Ecological overfishing of cod in New
England led to the rise of dogfish communities. Removal
of oysters in the Chesapeake Bay has helped muddy the
US's largest estuary (Brooks 1891). Lessons like these
show that even heavily managed fisheries can deplete
species so dramatically that their normal ecological role is
lost. As a result, these ecosystems may be nothing like
their natural state.
Third, fishing is now a diverse enterprise in which
many species are exploited; there are few parts of the US
where fishing concentrates on just one species. When we
fish entire ecosystems, removing two-thirds to ninetenths of the biomass of many different species, we can
end up with a situation in which no species is technically
overfished, but the whole ecosystem is depleted and nonfunctional.
When exploitation reaches every corner of the sea,
these fisheries impacts become universal. Managers in
previous centuries did not face this problem because there
were always places in the sea where the technology of
fishing could not reach (Bohnsack 1996). However,
dredges can now navigate rocky seabeds that would previously have shredded nets, and the hunger of a populous
world leaves few corners of the ocean untouched.
It is crucial to leave some parts of the sea unperturbed
by these activities, so that in some places natural marine
communities can thrive, grow, and persist. A strategy to
establish reserves in every major marine habitat solves
the problem of pervasive impacts of exploitation, at least
in local protected areas. Reserve science has shown that
many components of marine communities respond
strongly to reserve protection, so this management device
can help promote crucial conservation goals that are otherwise unattainable.
Naturally, these fully protected areas do not serve all
conservation or management goals, and it is imperative
that they be joined by other types of marine management
schemes that allow access to the sea and its resources by
diverse user groups (Agardy et al. 2003). As part of a
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Marine reserves: the best option for our oceans?
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wider system of recreational, subsistence, and commercial
use of coastal areas, reserves have been integrated in
broader zoning schemes in Australia and the US, and
play a key role in biodiversity and conservation, even in
places where fisheries management is successful.
Just as the US has invested in a series of magnificent
National Parks and Wildlife Refuges on land to preserve
the nation’s natural grandeur and wildlife, a system of
marine wilderness areas in the oceans would preserve a
legacy of ecosystem vigor. In a make-believe world without overfishing, reserves would still be a national priority.
In the real world, where the entire ocean is open to the
scramble of fisheries overexploitation, they are even more
important.
References
Agardy T, Bridgewater P, Crosby M, et al. 2003. Dangerous targets?
Unresolved issues and ideological clashes around marine protected areas. Aquat Conserv 13: 353–67.
Babcock R, Kelly S, Shears N, et al. 1999. Changes in community
structure in temperate marine reserves. Mar Ecol Progress Series
189: 125–34.
Bohnsack J. 1996. Marine reserves, zoning and the future of fisheries management. Fisheries 21: 14–16.
Brooks W. 1891. The oyster. Baltimore: Johns Hopkins University
Press.
Halpern B. 2003. The impact of marine reserves: do reserves work
and does reserve size matter? Ecol Appl 13: S117–37.
Palumbi SR. 2003 Marine reserves: A tool for ecosystem management and conservation. Pew oceans Commission, Washington,
DC.
Peterson CH, and Estes JA. 2001. Conservation and management
of marine communities. In: Bertness MD, Gaines SD, and Hay
ME (Eds). Marine community ecology. Sunderland, MA:
Sinauer Associates.
Roberts CM.1997. Ecological advice for the global fisheries crisis.
Trends Evol Ecol 12: 35–38.
Dave Fraser
Captain, FV Muir Milach
Adak, AK, USA
Elliot Norse would have managers unleash
a virtual epidemic of MPAs, but not just
any strain. His prescription calls for a particularly virulent genus: “marine reserves”, also known as “no take
zones” (NTZs). As Tundi Agardy (2003) wrote, “The
enthusiastic prescription of simplistic solutions to
marine conservation problems risks polarization of interests and ultimately threatens bona fide progress in
marine conservation. The blanket assignment and advocacy of empirically unsubstantiated rules of thumb in
marine protection creates potentially dangerous targets
for conservation science.”
No one benefits from sound fisheries management
more than those dependent upon commercial, subsistence, and sport fishing. Good management requires
finding the right tool for the job. What is missing from
the current MPA/NTZ campaign is the critical need to
carefully define the problem before reaching for a tool.
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If overfishing is the problem, then as Andrew
Rosenberg (2003) said in this journal, “The only way to
end overfishing is to fish less.” In Alaska, as the
Chairman of the Pew Commission acknowledged, we’ve
seen the wisdom in that all along (Panetta 2002), which
is perhaps why we have no overfished groundfish stocks.
Time and gear closures of huge tracts of ocean have
long been facts of life in the North Pacific. In the Bering
Sea, year-round bottom trawl closures encompass about
30 000 square nautical miles, an area larger than Indiana.
Trawl closures in the Gulf of Alaska encompass 60 000
square nautical miles. Large expanses of the North
Pacific are closed seasonally for bycatch reduction or to
protect marine mammal habitat and feeding areas.
Together, these closures comprise some 25% of the continental shelf. More importantly, catch and bycatch are
limited and closely monitored through an observer program – without a network of permanent NTZs. In
Alaska, in short, fisheries management already proceeds
from the assumption that the entire ocean should be a
marine protected area.
Despite our experience in Alaska, Norse concludes,
“the case for reserves is so strong that it seems imprudent
to wait until implacable opponents of marine conservation are convinced by the evidence”. As an implacable
supporter of marine conservation – though a skeptic on
the value of NTZs as tools for fisheries management – I
prefer policy based on evidence.
So what is the evidence? Norse dismisses a study by
Shipp (2002) because it was funded by sport fishers. If
funding is an appropriate criterion for assessing validity
of scientific research, Norse’s conclusions as a Pewfunded author, citing a Pew commission report that cites
Pew-funded scholars, including himself, are also suspect.
In any case, let’s review their evidence. The Pew
Commission’s report on marine reserves (Palumbi 2003)
cites a variety of studies indicating that:
• proof of augmented reproductive capacity via larval
transport is rare, except with extremely over-exploited
species
• there are few US studies of NTZs (except for “boutique-size” closures)
• most studies are mathematical models
• effort control can achieve the same purposes
• reserve networks are poorly studied
• studies of reserves show beneficial results in specific
circumstances, where there are heavily exploited
species, that the benefits are stronger within reserve
borders, and that the effect is clearer for sedentary
species.
The evidence that NTZs offer substantial incremental
benefit to well-managed fisheries outside the NTZ is less
than compelling. In advocating NTZs, supporters should
clearly differentiate between NTZs as a fisheries management tool and NTZs as parks. Where NTZs can be
© The Ecological Society of America
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demonstrated to increase yields at a lower cost to fishers than other management tools, fishers will accept
the price of lost fishing grounds. However, were the
public to decide that it wanted to create a new
national park in the grasslands of Iowa, we wouldn’t
simply evict the farmers. Society as a whole would
shoulder the cost.
Scientifically-based closures, carefully designed to
accomplish specific goals, are part of a broader set of
management tools that together provide sustainable
fish populations and sustainable fisheries with the
economically important jobs they provide. But habitat
protection measures are not simple; there are endless
gradations between totally open and completely
closed. From the perspective of the fishing community, any measure should meet four critical tests.
MPAs must be scientifically justified, have clearly
articulated goals, incorporate provisions for continued
monitoring to ensure that those goals are being
achieved, and their creation must take into account
existing closures.
The Northwest Indian Fisheries Commission (Franks
2003) and Pacific Coast Federation of Fishermen’s
Associations (PCFFA 2002) have thoughtful online policy statements on MPAs, NTZs, and sustainable fisheries, which articulate the concerns of the broader fishing community. Due to space restrictions, I have posted
links to their sites and further discussion of the fishing
community’s perspective on MPAs and NTZs at
www.olympus.net/personal/dfraser/mpalinks.htm.
“For every complex problem”, wrote HL Mencken,
“there is an answer that is clear, simple, and wrong”.
Properly considered, researched, and implemented, various types of MPAs adapted to specific circumstances may
prove useful. Applied broadly without meaningful participation by stakeholders in the fishing community and
other interest groups, they will engender conflict and
resistance. Let’s get it right before we unleash an epidemic of NTZs.
References
Agardy T, Bridgewater P, Crosby MP, et al. 2003. Dangerous targets? Unresolved issues and ideological clashes around marine
protected areas. Aquatic Conserv 13: 353–67.
Franks B. 2003. Northwest Indian Fisheries Commission tribal policy statement on marine protected areas, marine reserves,
marine sanctuaries, and fishery conservation zones. www
.nwifc.org/newsinfo/MPAs%20.pdf. Viewed Oct 8 2003.
Palumbi SR. 2003. Marine reserves: a tool for ecosystem management and conservation. Chapters III and IV. Arlington, VA:
Pew Oceans Commission.
Panetta LE. 2002. Panetta’s new passion reviving ocean fishing.
NPR Morning Edition. Dec 12.
PCFFA (Pacific Coast Federation of Fishermen’s Associations).
2002. Principles of the Pacific Coast Federation of Fishermen’s
Associations regarding marine protected areas. www.pcffa
.org/mpa3.htm. Viewed Oct 8 2003.
Rosenberg AA. 2003. Overexploitation of fisheries. Front Ecol
Environ 1: 102–07.
© The Ecological Society of America
Marine reserves: the best option for our oceans?
Peter Kareiva
Lead Scientist, The Nature Conservancy,
Seattle, Washington, USA
Marine conservation lags behind terrestrial
conservation in funding, science, and
implementation. The sluggishness with which we have
come to focus on marine conservation is inexcusable.
However, there is some advantage to not being first. In
particular, we can learn from the successes and failures
associated with longstanding systems of parks and wildlife
preserves on land. As we race to establish MPAs, we
should pause to consider the following ten lessons that are
gleaned from our experience with terrestrial conservation.
• Terrestrial parks have often been located in the wrong
places – typically those that are of little economic value
(Scott et al. 2001). For example, in the US we have
many national parks in areas of snow and rock, with little productivity or biodiversity. If we take a similar
approach to marine conservation, and place MPAs
where political forces offer the least resistance, we will
end up with an ill-designed reserve network.
• Many supposedly protected terrestrial areas are in fact
no more than “paper parks”, in which a lack of enforcement results in poaching, illegal logging, and even mining. Enforcement will probably be an even greater challenge in the marine realm.
• Global climate change is real and represents a serious
challenge to the design of any reserve network. Parks
that are fixed in space therefore risk becoming obsolete.
Clearly, consideration of resilience in the face of climate change should be a part of any plan for MPAs
(West and Salm 2003).
• Invasive species are the greatest threat to terrestrial
reserves, but have not figured prominently in discussions of marine conservation. However, invasive
species often dramatically alter marine ecosystems
(Simberloff 2000). Marine reserves will require as much
protection against non-indigenous species as against
harvest or other human disturbances.
• All too often, terrestrial conservation has focused on
collecting long lists of species, with little attention paid
to the maintenance of critical ecological processes. In
terrestrial systems these processes include natural disturbances such as fires and floods. In marine systems
they could include freshwater inputs and recolonization
following large disturbances such as hurricanes.
Whereas a relatively small area may capture many
species within its borders, it usually takes a much larger
area to protect ecological processes.
• On a related note, a myopic focus on the accumulation
of long lists of species within the smallest possible area
(biodiversity hotspots) can fail to protect the diversity
of ecosystems and ecosystem services (Christensen
2003; Kareiva and Marvier 2003). A focus on species
protection will typically lead to a very different allocawww.frontiersinecology.org
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Marine reserves: the best option for our oceans?
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tion of conservation effort than would a focus on the
conservation of ecosystem diversity. Both species protection and ecosystem protection should be considered
in plans for marine conservation.
• Corridors and connections between terrestrial reserves
are widely embraced in theory, but poorly documented
with data (Simberloff et al. 1992). The same mismatch
between theoretical appeal and empirical support is
evident in marine discussions of “connectivity”. Before
rushing to invest in marine corridors, we should await
some convincing evidence of their effectiveness.
• The ecological status of the matrix in which terrestrial
reserves are embedded can be as important as the
integrity of the parks themselves (Daily 1999). It may
be impossible to achieve our conservation goals if we
focus too narrowly on marine reserves to the neglect of
the surrounding human-dominated landscapes and
seascapes.
• Wide-ranging species such as caribou, salmon, and
migratory birds have posed special challenges to conservation planners in terrestrial settings (Groves 2003).
These same challenges will apply to the many wideranging marine species, and will require a much more
complicated strategy than just networks of biodiversity
reserves.
• No nature reserve system can be sustainable without
also making sure that local human populations are provided for (UNCED 1992). This principle will certainly
hold for coastal fisheries, which many local communities rely on for livelihood and food.
Much is made of the unique challenges posed by marine
conservation. While marine systems have extraordinary
biological nuances, many of the lessons learned from terrestrial conservation will surely apply equally well in a
marine setting. The critical difference between marine
and terrestrial conservation has less to do with biology
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than with the policy context and political justifications
used when arguing that marine areas should be set aside as
reserves. Specifically, advocates of MPAs commonly argue
that the spillover of fish from within these areas can supplement harvest in surrounding zones, and hence provide
a win–win conservation tool (protected biodiversity and
greater harvest). Meanwhile, on land, no one asks that
terrestrial protected areas produce a surplus of wildlife that
spills over and supports surrounding hunting communities. Perhaps we should think about MPAs in the same
way we think about terrestrial parks – simply as secure
havens for biodiversity. The real challenge for marine
conservation may well lie in the management of nonreserve areas, which we risk neglecting in our fondness for
MPAs.
References
Christensen J. 2003. Few habitats, many species, and a debate on
preservation. New York Times. July 1: Sect D: 1.
Daily GC. 1999. Developing a scientific basis for managing Earth's
life support systems. Conserv Ecol 3: 14. www.consecol.org/
vol3/iss2/art14.
Groves CR. 2003. Drafting a conservation blueprint. Washington,
DC: Island Press.
Kareiva P and Marvier M. 2003. Conserving biodiversity coldspots.
Amer Scientist 91: 344–51.
Scott JM, Davis FW, McGhie G, and Groves C. 2001. Nature
reserves: do they capture the full range of America’s biological
diversity? Ecol Appl 11: 999–1007.
Simberloff D. 2000. No reserve is an island: marine reserves and
nonindigenous species. Bull Marine Sci 66: 567–80.
Simberloff D, Farr JA, Cox J, and Mehlman DW. 1992. Movement
corridors: conservation bargains or poor investments? Conserv
Biol 6: 493–504.
UNCED (United Nations Conference on Environment and
Development). 1992. The Rio declaration on environment
and development. New York: United Nations.
West J and Salm R. 2003. Resistance and resilience to coral bleaching: implications for coral conservation and management.
Conserv Biol 17: 956–67.
© The Ecological Society of America