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Unraveling a Fish Myth. Unraveling a Fish Myth. Pervasive rhetoric: …aquaculture is less efficient than traditional fishing… “It takes 2-5 lbs of wild fish to produce 1 lb of farmed fish. If you do the math, this isn’t sustainable.”
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Unraveling a Fish Myth • Pervasive rhetoric: …aquaculture is less efficient than traditional fishing… • “It takes 2-5 lbs of wild fish to produce 1 lb of farmed fish. If you do the math, this isn’t sustainable.” • Dir. Center for Coastal and Watershed Systems, Yale University • Back to basic biology
Unraveling a Fish Myth • TE in Nature • Avg. trophic efficiency = 10% • 10lbs (L#N) 1lb (l#N+1) • Fish Prod = Prim Prod x (TE)↑exp TL
0.9 large tuna, sharks, billfish (0.7) 4.65 6.21 small tuna, salmon, squid (4.65) 31 31 chaetognaths, micronekton (31) mesopelagic vertical migrators (63) 157 313 470 crustacean zooplankton (470) DOC (32,776) 2,351 2,351 ciliates (2,351) 11,754 11,754 flagellates (11,754) bacteria (16,388) 42,380 18,163 algal picoplankton and nanoplankton (60,543)
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)
Unraveling a Fish Myth • TE in Aquaculture [Avg. 40-60%] • WHY? • Nutritional profile of pelleted feeds • Little energy expended hunting for food • Bite-sized pellets size means little waste • Also, no by-catch waste • AQ feeds now 10-25% fish meal