Biology 1229

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Biology 1229

• Fisheries
• or
• Should fish be on the menu?

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Fish on the menu

• At least 2.5 Billion people depend on fish for
  more than 20 of the protein in their diet
• 97 of fishers are in developing countries

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Why might fish be on the list?

• Mercury

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Why might fish be on the list?

• Farming practices unsustainable
• Shrimp farming in Mexico destroys mangrove
  forests
• Salmon farming
• Escapes
• Parasites
• Eutrophication

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Why might fish be on the list?

• Fishery unsustainable or environmentally damaging

Bottom trawling
Bycatch from a shrimp net!
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Unsustainable fisheries
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How does a harvested population work?

• Note sustainable is economic, not based on the
  population!!!
• It is possible to derive a MSY from population
  data using growth rate and harvest rate

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Orange RoughyHoplostethus atlanticus

• Slow, ugly, demersal fish (Slimehead)
• Mature at 20-30
• Live up to 156 years (depending on who you listen
  to)
• Harvested by bottom trawling around sea mounts
• Fishing, or mining?

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How much of the ocean is harvested?
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Fishing down the food web
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How many fisheries are sustainable?
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What about recreational fishing?
Including menhaden and pollock
Commercial Fishery
Recreational fishery as a age of commercial
But the vast majority of several high-value,
threatened species (e.g. Red Snapper) are caught
recreationally
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We are catching too many fish!!
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Not just fish suffer

• Effects on seabirds other top predators
• Effects on erosion and flood control (e.g. New
  Orleans)
• Economic effects of fishery collapse
  (Newfoundland)

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Top 20 countries for unsustainable fishing

• China
• Peru
• Japan
• Chile
• USA
• 18. Canada

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What future?

• Some authors predict the collapse of ALL
  fisheries by 2048
• Sustainable management is possible requires
• Reliable data
• Reliable fisherman
• A pretty decent navy
• End of oil may result in reduced fishery pressure

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Ownership of fisheries prevents collapse
With ITQ
Without ITQ
Number of Individual transferable quota (ITQ)
fisheries
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See also
http//www.mbayaq.org/cr/seafoodwatch.asp