World Fisheries

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World Fisheries
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Change in Catch for Major Marine Fishing Regions,
Peak Year to 1992 (in millions of tons)
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• The growth in the marine catch has been due to
  finding new fishing grounds and catching new
  species. Fishing fleets progressively work their
  way from the most desirable and easiest to catch
  to less desirable or more elusive species.
  Further growth is limited since almost all
  fisheries have been exploited and few untapped
  species exist.

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• Worldwide fish and other products of the sea
  account for 16 of animal protein consumption -
  more than either beef of pork.
• In developing countries fish are often caught and
  exported to generate cash income to repay debts
  to IMF and World Bank. This forces locals to
  compete with international buyers for an
  important food source.

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• Between 1970 and 1990 the world fishing fleet
  doubled in size. It is now twice the capacity
  needed. Increased fleet size allows nations to
  capture more of the common resource, as countries
  race each other to get the most fish possible.
  As fisheries decline, bigger, faster boats help
  some fishers maintain their catch levels.
• As fishers lose money, politicians may subsidize
  them, causing more over-fishing. Worldwide,
  governments annual subsidize fishing fleets by
  54 billion to catch 70 billion worth of fish.

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• There is little reason to believe that the
  global catch can ... expand, except for increases
  that might occur through more effective
  management of stocks.
• FAO Marine Fisheries and the Law of the Sea
  (1993)
• Economists estimate Iceland could increase its
  GNP by 4 by managing its fisheries more
  efficiently.
• Indeed, what is so fascinating - and also tragic
  - about the fishing industry is that it actively
  participates in its own annihilation. James
  McGoodwin Crisis in the Worlds Fisheries

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• To put fishing on a sustainable path stocks must
  be allowed to recover in areas suffering from
  over-fishing.
• ITQs - Individual Transferable Quotas
• Fishers are assigned ITQs which they may use or
  sell or lease. The sum of the ITQs should be the
  sustainable annual harvest.
• Why is transferability important?
• Why not just issue 5-year permits?
• Does it matter if a few companies buy all the
  ITQs in a fishery?

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• Fencing the Oceans
• EEZs - Exclusive Economic Zones - zones up to 200
  miles from the coast that a nation controls.
  Assigns ownership to the fishery.
• Some countries sell fishing rights in their EEZs.
• The European Union pays 200 million per year in
  access fees, half to African nations.
• England earns 45 million from its Falkland
  Islands fishing area leases.

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• By-catch - the catch of non-target species - is
  growing. As fishers target high profit species
  they throw back other species often dead or
  dying. By-catch may be as high as 20 million
  tons per year (20 of total harvest). Some
  by-catch are valuable species - e.g., shrimp
  netters throw out red snapper, ruining that
  fishery. Small-scale or indigenous fishing has
  almost no by-catch waste.
• In the North Sea, 2 to 4 kgs is discarded for
  every kg. kept!

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• Coastal areas are key to marine fisheries.
  Nutrients from land support a higher density of
  life than do the open oceans. More than 90 of
  the marine catch comes from the 10 of oceans
  closest to land.
• Worldwide, development has destroyed almost 50
  of coastal wetlands where many fish live or
  spawn.
• Damming rivers reduces nutrients going to the
  sea. After the Aswan Dam was completed the
  concentration of phytoplankton in the Nile Delta
  fell by 90 and the sardine catch dropped from
  18,000 tons to about 600 tons.

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• Pollution from land has reduced Chinas marine
  catch by an estimated 210,000 tons and reduced
  catches in Chesapeake Bay by as much as 90 in
  some species.
• Use traditional fisheries management systems.
  Coastal peoples successfully managed their
  fisheries for thousands of years. Local
  knowledge may be key to protecting fisheries.

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• Fisheries are a COMMON ACCESS or OPEN ACCESS
  RESOURCES.
• OPEN ACCESS because no one is excluded from using
  the resource.
• COMMON ACCESS reflects the concept of the grazing
  common.
• No ownership rights assigned to the resource so
  no one has the authority to manage to resource.
• Open access and lack of management almost always
  lead to overuse.

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• Incentives for overuse of a commons
• Suppose you do the right thing and only use your
  fair share of the commons. In a community of 10
  people, each person can safely graze 100 animals.
• Suppose one person cheats and grazes 200. Your
  animals get 10 less grass, so are 10 smaller
  than they should have been.
• To combat this loss you have an incentive to
  graze more than 100 animals. So do all your
  neighbors. The commons can support only 1,000
  but 1,500 graze there.

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• Everyone has an incentive to overuse the commons
  in order to get their share of the resource.
  Anyone who behaves properly (grazes 100) sheep
  obtains less than their share of the grazing
  benefits.
• To get your share you over graze the commons and
  so destroy it.
• In the long-run it would have been better for
  everyone to have played fair. All 10 people
  could have grazed 100 animals indefinitely.
• With overuse the commons may only support a few
  dozen animals until it recovers
• WILL PEOPLE LET IT RECOVER?

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Sustainable Harvest

• Consider the dynamics of a fish population
• Starting population P0
• Births B (new fish)
• Deaths (natural) D
• Harvest H
• This implies that P1 P0 B - D - H
• If we want to maintain a level population then
• P1 P0 so B - D - H 0 or
• Births must equal Deaths Harvest
• Assumes P0 is the optimal population

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Sustainable Harvest

• Can you really harvest B - D fish?
• Only if you have perfect information about Births
  Deaths.
• If you dont have perfect information and Births
  and/or Deaths you could over harvest. B D can
  vary because
• If fish get sick
• If older more fertile fish are harvested
• If environmental conditions change

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Sustainable Yield or Harvest

• This is living of the growth or interest that
  accrues every period.
• This level of harvest can go on forever if
  environmental conditions do not change very much.
• This is what we mean by SUSTAINABILITY, being
  able to continue forever.
• Acting with future generations in mind.