Marine biodiversity is affected by climate change and by fishing Keith Brander ICESGLOBEC Coordinato

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Marine biodiversity is affected by climate change
and by fishing Keith BranderICES/GLOBEC
CoordinatorCod and Climate Change Programme
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The Norwegian spring spawning herring
fishery Clergyman Peder Claussøn Friis
(1545-1614)
It comes up to the shore here from the great fish
pond which is the Icelandic Sea ...and here in my
days there have been two large and wonderful
herring fisheries at different places in Norway
and this fishery did begin to diminish and fall
away in the year 1560 it may well be that in
punishment for the unthankfulness of men it has
moved from place to place, or has been taken away
for a long period.
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The cod stock at Greenland extended northward
from 1920 to late 1930s.
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Conclusions

• Marine species and ecosystems have always adapted
  to climate change.
• Fluctuations in fish stocks and other marine life
  occurred before fishing pressure was high
• with big economic and social consequences for
  dependent communities.
• Nowadays fishing pressure is an additional stress
  on the biodiversity of marine populations.

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How does climate change affect distribution and
biodiversity?
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Rapid spread of tropical species along the
continental slope. Is more biodiversity always
good? 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 function? Is that
allowed to move too? Is fish production
affected? Should we be managing differently?
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• Why do marine species respond so quickly to
  climate change?
• They are adapted to disperse during early life
  (in the plankton)
• There are few physical boundaries in the sea
• Marine ecosystems are not structured by large,
  long lived plants
• Marine populations are very big and have wide
  ranges
• .

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how to prevent or minimise the adverse effects on
biodiversity of climate change?
Not like this
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how to prevent or minimise the adverse effects on
biodiversity of climate change?

• Reduce fishing pressure This will result in
• Larger population sizes
• More older fish in the population
• Less damage to the marine ecosystem
• Coupled with responsive, regionally appropriate
  management the consequences would be
• No loss of fisheries production
• Greater adaptability of populations to climate
  change

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Thanks for listening