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Fisheries Case Studies

Fisheries Case Studies. Japanese Pilchard (Anchovy) Norwegian Spring-Spawning Herring Canadian Pacific Herring Canadian Atlantic Cod North Sea Cod North Sea Herring. Clupeid & Gadoid Fisheries. r – Selected Species ~1/3 Global Fisheries Instability  Management Challenges.

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Fisheries Case Studies

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  1. Fisheries Case Studies • Japanese Pilchard (Anchovy) • Norwegian Spring-Spawning Herring • Canadian Pacific Herring • Canadian Atlantic Cod • North Sea Cod • North Sea Herring

  2. Clupeid & Gadoid Fisheries r – Selected Species ~1/3 Global Fisheries Instability  Management Challenges

  3. invertebrate carnivores (1.4) natural mortality and fishing pelagic fish (9.3) 6.8 2.3 crustacean zooplankton (9.1) ciliates (2.6) 42.75 42.75 flagellates (12.9) 64.5 phytoplankton (150)

  4. Anchovies

  5. Sardines

  6. Herring

  7. Commercial catch of Japanese pilchards

  8. Geographical distribution of the four subpopulations of Japanese pilchards and annual catch by region from 1972 to 1976. Numbers in circles are catch in thousands of tonnes.

  9. Kuroshio Current

  10. Survival of young Japanese pilchards from eggs to post-larvae at an age of ten weeks.

  11. Commercial catch of Japanese pilchards

  12. Norwegian spring-spawning Herring

  13. Migration routes of the Norwegian spring-spawning herring.

  14. Commercial catch, recruitment of 3-year old fish, and spawning biomass of Norwegian spring spawning herring.

  15. Percentage contribution of year classes of Norwegian spring spawn herring to the adult stock from 1954 through 1962. The very good year class of 1950 began first appearing in significant numbers in 1954 and dominated the adult stock throughout this period.

  16. Migration routes of the Norwegian spring-spawning herring during the period 1963-1966.

  17. Growth curves of Norewgian spring-spawning herring during various periods of time.

  18. The location of the nine major populations of British Columbia herring.

  19. Drum seining (small) vessels

  20. Time series of British Columbia herring catch

  21. Cod, Haddock, Pollock

  22. natural mortality and fishing large demersal fish (0.4) 16.3 8 2 16.3 invertebrate carnivores (61) pelagic fish (32.6) demersal fish (10) 102 29 306 crustacean zooplankton (408) macrobenthos (49) 20 epifauna (4) 408 225 ciliates (240) 1,800 bacteria (322) meiobenthos (19) 97 flagellates (1,200) 1,200 6,000 phytoplankton (9,000)

  23. Commercial cod landings in the northwestern Atlantic Ocean

  24. Commercial catches of cod in the North Sea

  25. (A) Catch of North Sea Herring and (B) spawning stock biomass of the autumn spawning herring. The dashed line in panel B is the target spawning stock of 1.3 Mt recommended by the ICES.

  26. Species to Avoid • Chilean Sea Bass • Orange Roughy • Atlantic Halibut • Bluefin Tuna • Shark • Atlantic Swordfish

  27. Chilean Sea Bass • Dissostichus eleginoides • Patagonian toothfish • Z = 150 – 12,500 feet • W ≈ 20 lb; age ≤ 50 yr • Sexual maturity ≈ 6-10 yr • Population doubling time ≈ 5=14 yr • Very long w.r.t. many Com’l fisheries • K-species

  28. Orange Roughy • Hoplostelhus altanticus • Mesopelagic habitat (3-9°C, 200-2000 m) • Atlantic and Pacific Oceans • Age ≤ 150 yr • Large spawning aggregations • 20,000 eggs/clutch; ferthatch =10-20d • Sexual maturity at 25-30 yr • K-species

  29. Atlantic Halibut • Hippoglosus hippoglossus • Z = 50 -2,200 m • Among largest boney fish in the world • Age ≤ 50 yr; L ≤ 5m; W ≤ 700 lb • Sexual Maturity: 7 – 12 yr ( m – f) • “Endangered-list” since 1996 • K-species

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