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

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

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

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

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

PCB’s in Salmon and other fish F One study found higher PCB’s (which may be a carcinogen) in Scottish farmed salmon compared to wild fish F 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 F Level of PCB’s in all cases were minute and well inside “safe” levels and comparable to many other common foods

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

PCB risk vs. cardiovascular risk F Every technical report of PCB’s in salmon has pointed out that heart benefits of salmon greatly outweigh cancer risks. F 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. F 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

Mercury in fish F Methylmercury is a by product of coal burning. F It bio-accumulates in top predator fish in freshwater and marine systems. F In freshwater – Pike, muskies are problems F In marine waters – sharks, swordfish and tilefish are of concern for pregnant and nursing women and babies F Sources: EPA and FDA

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

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

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

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

New Cage Designs

Cages for warm water marine fishes

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

Integrated shrimp farming

Shrimp and Seaweeds F Gracilaria and shrimp production in Hawaii

Shrimp and halophytes

Bivalve rearing – environmentally benign

Concerns with eating bivalves F Bioaccumulate toxins from algae blooms Neurotoxic Shellfish Poisoning Diuretic Shellfish Poisoning Vibrio cholera F Do not eat wild bivalves in months without “r”s F Farm raised bivalves are monitored and much safer

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

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

Improved processing of farmed products

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

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