Climate Cycles and Fisheries

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Climate Cycles and Fisheries

• November 29, 2007

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Climate

• What is climate?

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Natural Climate Variabilty

• Earths climate varies naturally on many
  different time scales
• Daily
• Annually
• Over several years
• Longer time scales

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El Nino - Southern Oscillation (ENSO)

• Climate cycle driven by the Equatorial Pacific
• Two Phases
• Normal - La Nina Conditions
• Warm - El Nino Conditions
• How often do El Nino conditions occur?
• What drives El Nino?

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Effects of El Nino

• Rain
• Temperatures
• Primary Productivity
• Fish Catch
• Flooding

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Long Time Scale Variation

• Ice Ages and Interglacial Periods
• Major changes in temperature and sea level
• What causes these natural cycles?

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Studying Past Climate

• Stable Oxygen Isotopes
• Ice Cores
• Fossilized remains

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Fisheries

• Finfish
• constitute 84
• Shellfish

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Fisheries

• What do we harvest fish for?
• Food
• Fish meal (for livestock etc.)
• Fish oil (margarine, cosmetics, etc.)
• Recreation
• Aquarium trade
• Marine natural products

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• Used to catch schooling fish like herrings,
  anchovies, sardines
• Surround and trap schools

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• Used to catch demersal fish, such as cods,
  pollock, haddock, etc.
• Dragged along the bottom

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Fisheries
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Overfishing
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Bycatch
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Managing Resources
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Mariculture