Marine Protected Areas

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Marine Protected Areas

• Largely taken from NRC reportMarine protected
  areas, tools for sustaining ocean ecosystems

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Objectives of MPAs

• Conservation of biodiversity and habitat
• Protect depleted, threatened, rare or endangered
  species or populations
• Preserve or restore viability of representative
  habitats
• Fisheries Management
• Control exploitation rates
• Protect critical life stages
• Reduce secondary impacts of fishing
• Ensure against regulatory failure or error
• Conserve life history traits and diversity

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More objectives

• Scientific knowledge
• Provide a source of baseline data
• Educational opportunities
• Enhancement of recreation and tourism

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Potential costs and benefits yield

• May lower catch
• Uncertain benefits
• For severely overfished stocks large closures may
  be required with negative impacts on other
  fisheries

• Adds stability to the resource
• Increased fecundity of resident stocks
• Possible increased future yield and recruitment
• Possible lower by-catch

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Costs and benefits displacement

• Hardship on local fishermen and businesses
• Increased impact in open areas

• Reduces exploitation rates (as in conventional
  management)
• Satisfies legal requirements for fish habitat

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Costs and Benefits Enforcement

• Requires enforcement of boundaries
• Additional costs over and above existing system

• Closed areas reasonably easy to enforce compared
  to catch or effort limitations

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Costs and benefits management

• New requirements for monitoring

• Improved estimates of biological parameters from
  contrast in abundance
• Promotion of spatially explicit management options

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Costs and benefits economics

• Disproportionate impact on communities bordering
  MPA
• Potential loss of yield and profits

• High potential for tourism
• Reduced conflict with non-consumptive users
• Possible increased yields
• Insurance against stock collapse

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Where MPAs may improve on catch or effort
limitation

• When few individuals are allowed to mature
• Strong Allee effects
• Where fishing reduces the abundance of one sex
• Imperfect control
• Where a large proportion of the effective egg
  production comes from a small area

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It would be nice

• If you could increase biodiversity and fisheries
  yields
• Without reducing effort!
• That is the essence of the MPA advocates claim!
• They say to fishermen let us close 20 of your
  fishing grounds and you will be better off.

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Claim 1If you close an area you have more fish

• On the one hand this is an obvious
  no-brainer
• On the other hand
• how big is the effect,
• how big does the reserve have to be
• where does that effort go?

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Halpern and Warner
Here we review 112 independent measurements of
80 reserves to show that the higher average
values of density, biomass, average organism
size, and diversity inside reserves (relative to
controls) reach mean levels within a short (1-3
y) period of time that the values are
subsequently consistent across reserves of all
ages (up to 40 y).
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Data from Eric Eisenhardt in San Juan Islands
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Hormone replacement therapy

• Administering menopausal women hormones to
  prevent symptoms of aging
• Studies of women on HRT indicated they had lower
  incidence of osteoperosis, heart disease and
  cancer
• Women on HRT tended to be wealthier and better
  educated than women not on HRT, but early
  analysis attempted to control this by comparing
  disease rates to women of similar incomes of
  women with and without the treatment etc.

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But when they randomized treatments!
The study placed women into three separate groups
to look at the effects of premarin and provera,
two types of hormones. Premarin is a form of
estrogen and Provera is a form of progestin.One
group received both premarin and provera, in the
second group the women had had hysterectomies and
were prescribed only premarin, finally the third
group received no hormones at all. The results of
one of those groups stopped many women and
researchers in their tracks.The group that took
both premarin and provera showeda 26 increase
in breast cancera 29 increase in heart
attacksa 41 increase in strokesand doubled
rates of blood clots in legs and lungs.
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Simple scientific method

• You cannot use local unprotected areas as
  controls because
• Protected areas were almost certainly different
  and likely more productive before protection
• The effort not going into protected areas goes
  into the unprotected ones
• A proper design would have control areas where
  there were no MPAs and compare total abundance
  in large areas including MPAs to large areas
  without MPAs
• None of the calls for large scale application of
  MPAs recognizes this basic element of science

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A precautionary taleEffort goes somewhere

• Rijnsdorp et al (2001) analysis of a closed area
  for cod in the North Sea
• Effort shifted to other areas
• Where skates and long lived species benthic were
  more vulnerable

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Closing areas to fishing moves effort

• This may have adverse biodiversity consequences
• This may have adverse fisheries management
  consequences
• If effort is reduced as part of the package the
  benefits will likely be from reduced effort, not
  the closed area

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Basic MPA theory

• If MPA is large relative to a species dispersal
  MPA increases abundance in MPA, and will lock
  up a fraction of resource with resultant loss in
  potential sustainable harvest
• If MPA is small relative to species dispersal it
  has no effect (Polacheck 1991)
• At some sizes there may be spill-over of larvae
  or adults that compensates for losses due to
  locking up

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It is recognized by everyone that we need to
reduce fishing effort

• Reductions in fishing effort have high social
  costs

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These promises may be too rosy

• Because blanket MPA programs may have significant
  adverse biodiversity and fisheries management
  consequences
• Because the basic numbers of 20-30 are derived
  from theory that assumes there are no other forms
  of fisheries management.

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More theory

• MPAs can, at best, produce fisheries yields
  equivalent to that achievable by other forms of
  fisheries management (Hastings and Botsford)
• But almost all models suggest much lower CPUE as
  a result
• MPAs will produce fisheries benefits primarily
  when stocks are recruitment overfished

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Empirical evidence

• Within MPAs that are enforced, average size and
  abundance increases, often dramatically
• Worldwide most MPAs have failed to meet their
  objectives Kelleher, et al. 1995
• Little if any empirical evidence regarding the
  amount of spill-over Roberts recent example in
  Science from St. Lucia showed increases outside
  the MPA in the first year, something not possible
  from MPA theory!

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Data from Roberts St. Lucia example
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What is wrong with this study?

• Effort was excluded from protected areas and went
  to unprotected areas
• Yet the unprotected areas still increased in the
  first year
• Average age at maturity for key species is 3-4
• This could not possibly have been spill-over
• Theory suggests abundance should have declined
  outside the reserve! If environment was constant.

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Georges Bank scallop
Abundance dramatically inside the closed
areas But also substantially outside And very
dramatically in Canada
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Pros for MPAs

• In areas where no other forms of fisheries
  management are effective, MPAs may be something
  that can be enforced
• For some species such as abalone and sea urchins,
  management by quotas leads to elimination of high
  density spawning aggregations which we want to
  maintain. MPAs are a crude form of spatial
  management
• For multi-species fisheries, traditional species
  by species quota management cant work for all
  species and MPAs may provide a method to protect
  the by-catch species and let the fishery chase
  the economically more important species

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The cons of MPAs

• For mobile species there wont be any
  conservation benefit, but costs will be imposed
  on harvesters
• For sedentary species you may lock up a
  significant fraction of the resource with little
  effective spill over
• If existing regulations have protected breeding
  stock, MPAs will provide no additional benefit

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More cons

• Fishing communities are also spatially structured
  so MPAs may impose severe costs on local
  fishermen
• The appropriate size for one species will be
  too big (lock up with little spill over) or too
  small for other species
• MPAs are not going to be an effective ecosystem
  tool for managing fisheries

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Why the push for MPAs

• The belief that traditional fisheries management
  tools have failed
• This is true in some places in the world that do
  not have effective fisheries management systems
• Within the US we at present obtain 86 of the
  potential sustainable yield (NMFS Our Living
  Oceans) and have an intense regulatory framework
• Potential improvement in fish yields is small

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MPAs as spatial management

• Management of many species can be improved by
  spatial management instead of quota management
  (abalone, urchins etc)
• MPAs are a form of spatial management but a blunt
  one that applies the same spatial scale to all
  species one size fits all
• It would be better to have spatial management
  systems that are appropriate to the biology of
  the species
• Enforcement is the problem in many high value
  species MPAs dont solve this

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Why 20-30 of the area

• Based primarily on optimum fisheries spawning
  stock (National Academy MPA report table 6-3)
• Assumes no spawning stock outside the reserves,
  which is untrue for almost all US fisheries

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From The Science of Marine Reserves
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MPAs are one tool of fisheries management

• Not a solution unto themselves
• Not a panacea
• Need to be evaluated along with other tools
• The benefits to fisheries yields are theoretical
  we need a lot of empirical evidence before we
  should embark on large-scale programs and expect
  fisheries benefits

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MPAs plans need to be evaluated in the context of

• the objectives regarding biodiversity and the
  fishery
• the alternative fisheries management actions,
  present and potential
• the social and institutional ability to maintain
  and enforce the closures,
• the ability to monitor and evaluate the success
  of the closures.

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Where we stand now

• MPA movement is implemented outside of the
  existing fisheries management institutions -
  California NZ
• Growing acceptance that MPAs are more about
  biodiversity reserves than fisheries management
• General acceptance that in places where other
  forms of fisheries management are not possible
  MPAs are a useful tool
• Large divide still exists one group views them
  as essential to ecosystem based fisheries
  management, another group sees MPAs as not an
  essential part of successful fisheries management.

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The California Process

• Moving through the state by area
• The Stakeholders
• The Science Advisory Team
• The Blue Ribbon Task Force
• The Fish and Game Commission

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The objectives

• To protect the natural diversity and abundance of
  marine life, and the structure, function, and
  integrity of marine ecosystems.
• To help sustain, conserve, and protect marine
  life populations, including those of economic
  value, and rebuild those that are depleted.
• To improve recreational, educational, and study
  opportunities provided by marine ecosystems that
  are subject to minimal human disturbance, and to
  manage these uses in a manner consistent with
  protecting biodiversity.
• To protect marine natural heritage, including
  protection of representative and unique marine
  life habitats in California waters for their
  intrinsic value.
• To ensure that California's MPAs have clearly
  defined objectives, effective management
  measures, and adequate enforcement, and are based
  on sound scientific guidelines.
• To ensure that the state's MPAs are designed and
  managed, to the extent possible, as a network.

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Stakeholder proposals
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Each dot represents an alternative MPA layout
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JadeA good management
Abundance with reserves
Abundance without reserves
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JadeA Black rockfishfailed management
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If catches depend on total biomass
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Points of interest

• Do the goals of the MLPA provide any guidance?
• How to deal with existing fisheries management?