Keith Brander ICESGLOBEC Coordinator Cod and Climate Change Programme Biodiversity objectives for fi

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Keith BranderICES/GLOBEC CoordinatorCod and
Climate Change ProgrammeBiodiversity
objectives for fisheries management why, what
and how?
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Objective preservation or rehabilitation of
biodiversity where it is perceived as being under
threat due to fishing or aquaculture activities
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Why is biodiversity a good thing?

• It just is! Intrinsic value. Beauty.
• (how much are people prepared to pay or forgo for
  this?)
• Future potential value (the new penicillin)
• Loss of biodiversity results in
• less effective and simplified food-webs where
  the energy flow in the ecosystem has been
  severely disturbed
• less resilience slow recovery of
  over-exploited systems
• less stability in the ecosystem - the
  jellyfish scenario
• Loss of fisheries productivity (e.g. adverse
  genetic change)

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Bergen Declaration Stakeholders, along with
scientists, managers and politicians, should be
involved at different stages of the decision
process to promote openness, transparency and
responsibility
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• Loss of biodiversity results in
• less effective and simplified food-webs where
  the energy flow in the ecosystem has been
  severely disturbed
• less resilience very slow recovery
• less stability in the ecosystem
• Loss of fisheries productivity (e.g. adverse
  genetic change)

Can we justify all these propositions? Is more
biodiversity always better?
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Devils Advocate

• We need to justify the propositions on which the
  biodiversity action plan for fisheries is based
• We need to evaluate the cost of preserving
  biodiversity

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An 18th C thought experiment

• The King of France has asked you to devise a
  strategy for sustainable fisheries and
  biodiversity in the Bassin d Arcachon.
• A new report (Duhamel du Monceau, 1771) and an
  earlier one (Le Masson du Parc, 1727), show the
  species composition, with a high proportion of
  large, long lived species e.g. Raia batis.
• Euler (1760) published the basic demographic
  equation, which can be used to estimate the
  mortality rate which such species can sustain.

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Report to the king

• Vulnerability and population decline due to
  fishing can be predicted from a life history
  model
• Some species have resilient life histories and
  others are sensitive to exploitation
• You cant make an omelette without breaking eggs
  if you want a fishery some species will
  disappear
• Losing top predators will produce higher yields
  from other desirable species, like sole
• In 250 years they will have forgotten that big
  long-lived species used to be common here and
  they will be worrying about biodiversity of other
  things
• Your majesty will unfortunately be among the
  extinctions

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The common skate grows to nearly 3 m long. It
used to be common from Morocco to Northern Norway
(including the western Baltic and Bassin
dArcachon), but is now rare and locally extinct.
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If your majesty would like oysters for dinner,
then please note that in 300 years most of the
oysters will be a new species introduced from
Japan
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The rise of aquaculture

• Fishing pressure has been a threat to
  biodiversity for hundreds of years (but has got a
  lot worse recently)
• Aquaculture in 2003 produced less than half as
  much as capture fisheries production, but has
  increased by 50 since 1997, while capture
  production decreased by 5
• This switch is like the agrarian revolution
  (involving enclosure ownership elimination of
  pests, predators and competitors selective
  breeding
• Aquaculture poses different threats to
  biodiversity and brings the marine situation
  closer to terrestrial

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Co-evolution of social-ecological systems
resilience, adaptability, transformability

• resilience capacity of system to absorb
  disturbance and reorganize, while undergoing
  change, so as to retain function, structure,
  identity and feedbacks
• adaptability capacity of actors to influence
  resilience
• transformability capacity to create a new
  system when ecological, economic, social
  conditions make existing system untenable

Us folks
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Agrarian revolutions examples of
transformability

• Ownership rights enclosure - elimination of
  pests, predators and competitors selective
  breeding
• Fisheries moving in this direction. Should one
  encourage this while seeking also to preserve
  natural habitat?

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Climate and biodiversity Climate induced changes
affect distribution and biodiversity Marine
ecosystems respond more rapidly than terrestrial
systems.
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Rapid spread of tropical species along the
continental slope Should we saythe ecosystem
is changing orthe ecosystem is
moving? Should we be concerned about the
conservation of particular species in
traditional locations or is it OK if they have
moved elsewhere? What about the conservation of
ecosystem functions? Is that allowed to move
too? Is fish production affected? Should we be
managing differently?
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Fisheries-induced adaptive changes

• What should the objectives of managing
  fisheries-induced adaptive changes be?
• What management tools will help us achieve the
  objectives?
• How do adaptive changes affect growth, maturity,
  fecundity, survival and stock/recruit
  relationships?
• Which species are vulnerable, under existing
  exploitation patterns?

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What should the objectives of managing
fisheries-induced adaptive changes be?

• Conserve biodiversity (resilience, continuing
  adaptive capacity). How much biodiversity?
  Where?
• Prevent undesirable change (e.g. small, less
  productive fish)
• Selectively neutral
• Promote desirable change

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ICES WG on Application of Genetics in Fishereis
and Mariculture (2004 and 2005)

• Recommend PMRN for
• restoration of the genetic composition of the
  stock
• sustainable harvest at current exploitation
  regimes while reducing the impact as far as
  possible

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What management tools will help us achieve the
objectives?

• Reference points and the precautionary approach
• EcoQ metrics e.g. PMRN
• Adaptive management (i.e. try and move in the
  right direction, monitor progress, get better at
  it)
• Add weight to existing management measures (e.g.
  allow more old fish to survive)

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Objective preservation or rehabilitation of
biodiversity where it is perceived as being under
threat due to fishing or aquaculture activities
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Conclusions

• Current biodiversity objectives assume that more
  is better
• This is naïve (or incomplete) because it leaves
  out details which matter, such as
• Spatial, temporal and taxonomic composition
• Cost
• The Bergen Declaration encourages an iterative
  process, which includes improving the objectives
  and we have a responsibility to work towards this

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