fisheries fish as food commercial fisheries trends in world fisheries solutions?

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  • Slide 1
  • Fisheries Fish as Food Commercial Fisheries Trends in World Fisheries Solutions?
  • Slide 2
  • Commercial Fisheries Traps Trawls Purse seines Gillnets Longlines etc
  • Slide 3
  • Purse seining
  • Slide 4
  • Trawling
  • Slide 5
  • Fish size-selective grid Cod Fishery - Norway
  • Slide 6
  • Gillnetting
  • Slide 7
  • Longlining
  • Slide 8
  • Technological Improvement in Fisheries
  • Slide 9
  • Tuna catches under floating objects
  • Slide 10
  • 0 1970 1990 1980 2000 10 20 30 40 Gross Registered Tonnage ( 10 6 tons ) 1960 Non corrected Corrected World Fishing Fleet Capacity
  • Slide 11
  • Production of Marine Fisheries
  • Slide 12
  • Production ( million tonnes) 50 100 180018401880192019602000 Year EEZs Claims Global Trend in Landings
  • Slide 13
  • Catches per 100 hooks (Japanese fleet) 1952 1964 1958 1980 Myers & Worm, 2003
  • Slide 14
  • Phase I - Undeveloped Phase II - Developing Phase III - Mature Phase IV - Senescent 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 1951195319551957195919611963196519671969197119731975197719791981198319851987198919911993 Percentage of resources Development Phases of World Fisheries
  • Slide 15
  • 0%10%20%30%40%50% Fully exploited Moderately exploited Overexploited Depleted Recovering Undeveloped State of Fish Stocks 1999
  • Slide 16
  • 0% 10% 20% 30% 40% 50% 60% 19701975198019851990199520002005 Fully Fished Moderately fished: U+M Overfished: O+D+R Trends in States of Fish Stocks
  • Slide 17
  • 1.00 0.94 0.92 0.87 0.86 0.83 0.81 0.73 0.71 0.44 0.43 0.39 0.14 0.00.10.20.30.40.50.60.70.80.91.0 IE PNW PSW PCW IW ANE AEC ASW PNE MBS PEC ACW ANW PSE ASE ANT 1.Antarctic 2.Atlantic, Southeast 3.Pacific, Southeast 4.Atlantic, Northwest 5.Atlantic, Western Central 6.Pacific, Eastern Central 7.Medit. & Black Sea 8.Pacific, Northeast 9.Atlantic Southwest 10.Atlantic Eastern Central 11.Atlantic Northeast 12.Indian Western 13.Pacific Central Western 14.Pacific Southwest 15.Pacific Northwest 16.Indian Eastern Ratio between Present & Historical Landings
  • Slide 18
  • Population Size (N) Time (t) = Maximum Sustainable Yield Maximum Sustainable Yield = Growth
  • Slide 19
  • Maximum Sustainable Yield Growth / Yield Fishing effort
  • Slide 20
  • Slide 21
  • Simple Abundance Model
  • Slide 22
  • Single Species Models Assessment models are biased because they do not incorporate the predation by other species. Assessment models are limited because of their emphasis on equilibrium solutions, such as MSY. Assessment models do not usually account for environmental changes, whether interannual or interdecadal. A correct assessment approach requires that a multi-species framework be used. Harvest recommendations from single-species assessment do not consider the needs of other species. Harvest recommendations from single-species assessment involve the deliberate fishing down of a population and therefore adversely change the ecosystem. The single-species approach is invalidated, because overfishing has occurred for at least a majority of the worlds fisheries. Single-species approaches do not account for the indirect effects of fishing (e.g. bottom fishing on habitat quality).
  • Slide 23
  • Slide 24
  • PSE AEC MBS ANT ANE ASW PNE PNW ACW PEC IE ANW PCW IW PSW 0%50%100 PEC PSW ANT PCW PNW IE ANW ASW MBS ANE ASE AEC PSE IW ACW 50%100 % GOOD BAD A: if fishing at MSY is good B: if fishing at MSY is bad Fishing at MSY level: is it good or bad?
  • Slide 25
  • Neoclassical Sustainability
  • Slide 26
  • Modern Sustainability
  • Slide 27
  • Fishery induced changes in world fish composition
  • Slide 28
  • Fishing Down the Food Web
  • Slide 29
  • Shark Populations NE Atlantic Baum et al. 2003
  • Slide 30
  • Fisheries have significantly contributed to human development and can still do so There are problem areas and avenues for positive change Change will never be at no cost; but.
  • Slide 31
  • Slide 32
  • Solutions?
  • Slide 33
  • Historical Succession of Coastal Ecosystems Jackson et al. 2001 1.Over-exploitation of large predators 2.Collapse Ecosystem Engineering species 3.Rise of Microbes
  • Slide 34
  • Historical fishing consequences Jackson et al. 2001
  • Slide 35
  • Historical fishing consequences Jackson et al. 2001
  • Slide 36
  • Historical fishing consequences Jackson et al. 2001
  • Slide 37

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