html5-img
1 / 27

Farmed Fish – Getting the Facts Straight

Farmed Fish – Getting the Facts Straight. Kevin Fitzsimmons, Ph.D. Professor of Environmental Science University of Arizona, Department of Soil, Water, and Environmental Science Tucson, Az Feb. 19, 2007. Overview.

tarika
Télécharger la présentation

Farmed Fish – Getting the Facts Straight

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Farmed Fish – Getting the Facts Straight Kevin Fitzsimmons, Ph.D.Professor of Environmental Science University of Arizona, Department of Soil, Water, and Environmental Science Tucson, Az Feb. 19, 2007

  2. Overview • Fish and other seafood are universally touted as highly nutritious and a key part of healthy eating • Some seafoods have been identified as contaminated or variable in nutritional values • Farmed seafoods have been reported to be more and less healthy than wild caught • Review of the science and consideration of benefits and risks

  3. Introduction • Seafoods, and fish specifically, are high in protein, minerals and vitamins • The fats that are present, tend to be polyunsaturated fatty acids • The omega 3 fatty acids are especially important

  4. Remember organic chem? • Found in many marine algae, canola, walnuts, soybean, and flaxseeds • Essential part of the nutritional requirement of almost all organisms • Important in neural and cardiovascular functions

  5. Facts about fatty acids in salmon • Most farmed salmon have slightly lower PUFA’s than wild salmon • However, the farmed product is still the next highest source of PUFA’s available • Moreover, farmers are rapidly adjusting feeds to increase omega 3’s

  6. Facts about fatty acids in other farmed fish • Fatty acids can also be elevated in non-salmonid fish depending on feed ingredients • Higher omega-3’s are expensive and will likely require higher price • Tilapia - Moderate in PUFA’s: 0.387 g/100g raw 0.600 g/100g cooked • Tilapia - Moderate omega 3 FA’s: 0.141 g/100g raw 0.220 g/100g cooked Source – USDA- ARS Lab

  7. PCB’s in Salmon and other fish • One study found higher PCB’s (which may be a carcinogen) in Scottish farmed salmon compared to wild fish • Several subsequent studies found PCB’s in wild and farmed fish, but level was dependent on PCB’s in source water, wild prey fish or in fish feed • Level of PCB’s in all cases were minute and well inside “safe” levels and comparable to many other common foods

  8. PCB risk vs. cardiovascular risk • Risk and Benefits • Levels in salmon vary from 0 to 30 ppb • FDA level of concern is 2000 ppb (2ppm) • EPA suggests that fish with 24 ppb or greater should not be consumed more than once per month • Above 24 ppb increased potential for cancer may be 1 in 100,000 • Comparison: Increased potential for cardio-vascular problems with high LDL’s is 1 in 2

  9. PCB risk vs. cardiovascular risk • Every technical report of PCB’s in salmon has pointed out that heart benefits of salmon greatly outweigh cancer risks. • Fish feed companies now screen feed ingredients for PCB’s. And today’s supplies of farmed fish are now lower in PCB’s than most wild fish. • In Western US, most farmed salmon comes from southern Chile, which has little industry, very clean water and undetectable levels of PCB’s in salmon

  10. Mercury in fish • Methylmercury is a by product of coal burning. • It bio-accumulates in top predator fish in freshwater and marine systems. • In freshwater – Pike, muskies are problems • In marine waters – sharks, swordfish and tilefish are of concern for pregnant and nursing women and babies • Sources: EPA and FDA http://www.cfsan.fda.gov/~frf/sea-mehg.html

  11. Mercury in fish • EPA frequently publishes advisories to limit consumption of wild freshwater fish • Current advisories for several lakes in Arizona, probably due to natural background levels in lakes • EPA advises to eat up to 2 meals of low mercury fish per week. • Farmed fishes have non-detectable levels, because they are grown in clean water and do not bio-accumulate from eating wild fish

  12. The actual EPA Advisory Brochure Examples: Shark (wild) = 0.99 ppm Tilapia (farmed) = N.D. to 0.01 ppm

  13. Artificial color added • Salmon and trout feeds sometimes include ingredients that impart reddish or pink color to the flesh. • Astanxanthin, canthaxanthin and beta-carotene are commonly used. • These may be plant or algae extracts, or chemically derived. • May also use whole algae as ingredient (Spirulina or Dunaliella) • Yes, the same extracts and algae sold in health food stores, (which was not included in the scare stories)

  14. Environmental concerns - Salmon Some cage farms have contributed to benthic pollution in the past. This is especially bad for the fish, so farmers rapidly moved cages to locations with more current and water flow. Most new cages are in deep water.

  15. New Cage Designs

  16. Cages for warm water marine fishes

  17. Environmental concerns with conventional shrimp culture • Loss of mangroves and other coastal vegetation.

  18. Integrated shrimp farming

  19. Shrimp and Seaweeds • Gracilaria and shrimp production in Hawaii

  20. Shrimp and halophytes

  21. Bivalve rearing – environmentally benign

  22. Concerns with eating bivalves • Bioaccumulate toxins from algae bloomsNeurotoxic Shellfish PoisoningDiuretic Shellfish PoisoningVibrio cholera • Do not eat wild bivalves in months without “r”s • Farm raised bivalves are monitored and much safer

  23. Aquaculture and fish farming • Aquaculture is making huge advances in production • Dozens of species of plants and animals are grown profitably • Aquaculture products continue to provide more seafood • Almost all aquaculture is more sustainable than commercial fishing

  24. Aquaculture and commercial fishing • 2005 UN-FAO reported 50% of all fish consumed globally were farmed • Most species are newly domesticated • No by-catch or ship pollution • Much safer for workers, fishing is US’s most dangerous occupation • Fishing is last major “hunting and gathering” lifestyle

  25. Improved processing of farmed products

  26. Competition with “wild” seafood: • US fishing industry complains about farm raised imports • Current tariffs on Norwegian salmon, Chinese crayfish, Vietnamese catfish, and shrimp from Brazil, China, Vietnam, Thailand and India • Wild fish have difficulty competing on price, quality and consistency

  27. Future of farmed seafoods • Commercial fisheries will phase out in favor of sport fishing • Farmed products will account for vast majority of seafood. • Environmental sustainability is increasing rapidly and will be achieved well before land farming. • Price and quality will continue to improve rapidly

More Related