Wednesday, July 1, 2015

Fish, Our Oceans, and Our Health - Pat II Farmed Fish

This is the second part to last years post Fish, our Oceans and Our Health.

If you live in the US and consume fish, chances are at least a percentage of the fish you eat are from fish farms. Roughly half of all fish consumed in the U.S. is now from the aquaculture industry, which is the fastest growing animal agriculture segment - in part due to misinformation about the sustainability and health of the product. Unfortunately farmed fish are not the paragon of sustainability the industry wants us to believe.

While many farmed fish live on GMO corn or soy, certain fish cannot do that. Fish like tuna and salmon need to eat as much as 5 pounds of fish for each pound of body weight. The result is that feeder fish are being fished to the brink of near extinction to feed the world’s farmed fish. 

This, of course, has a negative impact on the populations of everyone’s favorite aquatic creatures- whales, dolphins, seals, and sea lions as well as others - as their food supplies are quickly disappearing. As Dr. Richard Oppenlander writes, “It is a bizarre, ecologically unhealthy circle, where the demand to eat fish has taxed the oceans so there has been a proliferation of controlled fish-farm production, which places further stress on the oceans because of the need for fish-meal and oil in the production process.”

Not surprisingly, the fish that are fed corn or soy are far less nutritious than their wild caught friends. Loaded with toxins and lacking in the Omega 3s fish are famed for, farmed fish make a great Christmas present for someone you hate. Since wild caught fish get their omega 3 fatty acids by consuming plants (the same way we should!) or from eating smaller fish that eat plants, farmed fish, which are typically fed corn, soy, or other foodstuffs (as well as healthy doses of antibiotics just for good measure) contain little or no omega 3s. Instead these unnaturally raised fish accumulate large amounts of unhealthy fats and very little of the omega 3s for which they are so valued in many circles.

Furthermore a new report shows that the mercury levels in many fish actually cancel out the benefits of consuming their Omega 3s in the first place, and since food is a packaged deal, it’s impossible to just order the Omega’s while holding the mercury or PCBs on the side! One study that looked at 364 children in California found all of them exceeded safe benchmark levels for arsenic, mercury as well as the banned pesticide DDT among others. The paper argued that the children's exposure to these toxins was largely due to their diet, and actually suggested that the best way to avoid them was by eating lower on the food chain, and specifically pointed to a plant-based diet as ideal.

Another problem with farmed fish is increased disease among the fish. Disease spreads among fish just like it does in any other population. Since farmed fish - like their hoofed and beaked feed-lot counter parts- live in their own excrement, diseases spread quickly.  Not only our diseases rampant among the fish in the tanks, but if any of them escape, they can also spread unusual diseases among wild fish populations, only furthering the destruction of the rivers and oceans (do yourself a favor and don’t google sea lice!). As one professor of fisheries at the University of British Columbia has noted, fish farms “are like floating pig farms.”

Farmed fish also have a huge impact on our oceans environment. Vast amounts of feces, fertilizers, and antibiotics can all cause the death of plants and sea life, as it causes massive algae populations that leave inadequate oxygen for other forms of life. Known as “dead zones” one need not look further than the Gulf of Mexico where there is a dead zone – where nearly all the fish and plants have died – that is roughly the size of half of Maryland.

It is also worth noting that currently nearly 70% of all farmed fish come from China where they have weak standards regulating toxins, antibiotic use, and almost no concern for the environment.

For those that claim fish farms are the answer for how to get healthy, sustainable protein, they should really reconsider that stance. The weight of the evidence is against it. 

Sorry for the incredible delay in posting part II. My original draft and research was lost and it took a while to find the motivation to re-do it.

Further Reading:
“Overfishing: Plenty of Fish in the Sea? Not Always.” National Geographic.
Ivan Macfadyen, “The Ocean is Broken.”
Pauly, D., et all. “Towards sustainability in world fishers,” Nature 2002.
General Situation of World Fish Stocks, United Nations Food Agriculture Organization (FAO)
Harrington, J.R., et all., “Wasted Fishery Resources: Discarded By-Catch in the USA.” Fish and Fisheries 6.
Janicke Nordgreen, et all., “Thermonociception in fish: Effect of two different doses of morphine on thermal threshold and post-test behavior in goldfish.”Elsevier
Rosamond L. Naylor, et all., “Effect of Aquaculture on World Fish Supplies,” Nature Vol. 405, June, 2000.
Oppenlander, Richard. Food Choice and Sustainability: Why Buying Local, Eating Less Meat, and Taking Baby Steps Won’t Work. New York, Langdon Street Press, 2013.

As always the information presented in this blog is for educational purposes only. It should not be considered as specific medical, nutritional, lifestyle, or other health-related advice.