BYOL: environment

Showing posts with label environment. Show all posts

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.

Sunday, June 1, 2014

Fish, our Oceans, and our Health Part I

Last summer I had a ~~argument~~ conversation with a family member who is the typical gun-totten, freedom-lovin’ ‘Merican that has come to personify the American Right. We don’t always see eye-to-eye, as we are essentially polar opposites, but he is family and has always been there for me when I needed him (typically arriving 20 minutes late, but still… eventually he’s there). Basically the conversation was about our diets impact on the environment - he categorically and instantly argued that fishermen are catching record levels of fish, as an indication that the world’s oceans are perfectly healthy.

While I will probably never convince him otherwise, the evidence is pretty stark in the opposite direction. So today I’d like to talk about the choices you have: plant-based versus meat-based diets, and how they influence the marine environment. These choices we make have a dramatic effect, and it’s helpful to understand the impacts some of our choices have on the global environment. Because this is such a long post, I've decided to break it into three parts. This is Part I which will focus on our current fishing practices. Part II will focus on Farmed Fish, and finally Part III will talk about some of the health concerns involved in eating fish.

The oceans are currently stressed from the amount of fishing and unfortunately, farmed fish are no better of a choice, and come with their own host of problems (discussed in Part II). Today our global fish population is experiencing something of a crisis - and the idea that our oceans are inexhaustible can no longer go unnoticed.

Beginning in the mid-20^th century, international efforts to increase the availability and affordability of protein-rich foods led to concerted government efforts to increase fishing capacity. Favorable policies and government subsides spawned a rapid rise of big industrial fishing operations.

If you look at this graph from a 2003 paper in Nature, they show, in stark terms, the decline of large predators in the ocean. These are the most popular fish to hunt and eat and as the chart demonstrates, there has been nearly a 90% decline in their overall populations. The graph can be read as an indicator of the concentration of fish remaining in the ocean. As Ivan Macfadyen recently wrote in his piece for the Herald, “The Ocean is broken.”

Another figure to help demonstrate this point is the total number of fish we bring in. According to international law, when fish are brought to port, fishermen are required to report their catches; and various organizations have kept track of these numbers since the 1960s. Since the ’90s, the total number of fish caught globally has leveled out. In 1989, 90 million metric tons of fish were taken from the ocean, representing a high-water mark. We have maxed out the ocean’s ability to produce since then.

According to the Food and Agriculture Organization of the United Nations (FAO), of the 600 marine fish stocks they monitor, 52% have been fully exploited and all of the 17 primary fishing stocks worldwide are either overexploited or on the verge of collapse. In 2003, a report announced that industrial fishing had reduced the number of large ocean fish to just 10% of their pre-industrial population. Examples of this collapse are the Grand Banks near Newfoundland and the Georges Banks of New England, both once considered the most productive fishing grounds on the planet, and both now nearly devoid of life.

While still hotly debated, many scientists are now supporting the theory that if current practices continue, all of the world’s fisheries could collapse by 2048.

Another indication of stress in the ocean is the average trophic level of fish caught throughout the globe. Harking back to high school biology class, a trophic level is the position in the food chain for a particular species. If a fish eats algae, it’s at the first tropic level. If it’s a carnivore that eats smaller fish, then it’s one level up and so it continues up to the largest predators in the oceans. Because the higher trophic-level fish, such as swordfish or tuna, bring in such large profits (some tuna sell for over $1 million dollars!) these are the preferred fish for fishermen. However, as their populations have declined, they’ve become more difficult to catch. The result is that fishermen have moved down the trophic-level. These fish have less value per pound but are currently more available than the higher trophic-level fish.

The impact of this is that we are now literally scraping the bottom of the ocean floors for whatever is left. Having to move down on the trophic-level is a dramatic indication that we have fished beyond sustainable levels.

Besides reducing the populations of the fish fisherman actually want to catch, we have also had a negative impact on less desirable species. Due to a process known as by-catch- fish unintentionally caught- many species have become endangered simply because we want to eat other fish. Sharks and more surprisingly seagulls have been large victims of this wasteful practice. Feel free to google image this. The images are too depressing for me to put up.

Finally, bottom trawling is, perhaps, the worst of all fishing practices. Basically, fisherman drag nets across the bottom of the ocean floor and gather everything in their wake. At the surface, they discard as much as 70% of what they pull up – all of it dead. It is a common practice used when shrimping.

Unfortunately, the giant marlin that Santiago wrestled in Hemingway's "The Old Man and Sea" is becoming increasingly rare, and some day may only be found in the imagination of fiction. These issues about our environment and ecology need to be part of the public discourse. We need to face these hard truths if a true solution is to be found.

Additional Reading:

http://www.mindbodygreen.com/0-11561/9-things-everyone-should-know-about-farmed-fish.html.

“Overfishing: Plenty of Fish in the Sea? Not Always.” National Geographic.

Ivan Macfadyen, “The Ocean is Broken.” http://www.theherald.com.au/story/1848433/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.

Thursday, March 29, 2012

An Inconvenient Truth; Local or Vegan?

Recently I’ve seen a lot on local foods. I even attended a presentation on the importance of supporting green markets, co-ops and local farmers back in January. As the bumper sticker saying goes: “No Farms, No Food.” And on a basic level I completely agree. But to what point is local meat acceptable? Clearly, murdering an animal within 100 miles of where you live is no more morally acceptable than murdering an animal across the country, but from an environmental standpoint, where do we stand? What is right; local or vegan?

Over the past few years, the popularity of eating “local” has burgeoned. It has doubled in retail sales, and recently even the environmental disaster known as Wal-Mart announced they are increasing the amount of local food they will carry in each store, currently comprising roughly 9% of all their food sales. This recent surge in popularity is most likely related to the tremendous success of authors like Michael Pollan and Jonathan Safran Foer, both of who urge consciousness when it comes to purchasing food, not to mention the enormous popularity of documentaries such as FOOD inc. With most of our food traveling around 1,500 miles to reach our plates and with gas prices skyrocketing it seems logical that food grown closer to home would have lower transportation costs and would therefore be both more cost effective, but more importantly environmentally friendly.

However, there is one catch. Most “local” eaters also support eating locally raised and slaughtered meat and they typically fail to mention the impact rising animals for food has on the environment. But fortunately, others have begun to make the connection. Ironman triathelte Brendan Brazier’s newest book Thrive Foods and this recent article published in the Journal of Environmental Science and Technology seem crystal clear. Even the United Nations reported that eating less meat is the most affective way to curb global warming.

While the authors of these works admit most food travels around 1,000 miles and 4,000 miles across the entire supply chain, transportation costs comprise only 11% of the total carbon footprint of that food. Instead nearly 83% of the carbon footprint of food comes from growing and producing it (the other 6% is divided among various steps unrelated to either transportation or production). Essentially, each food has it’s own greenhouse gas intensity level. Red meat has the most intense level, requiring nearly 150% more energy than even chicken. This is in part because cows release a high amount of methane gas. However, they also require more emission-producing care, raising their overall carbon footprint. Thus, beef and dairy are often listed as the two worst foods for the environment, local or otherwise.

The article continues along these lines, and ultimately concludes that shifting your diet away from meat and dairy and towards a more vegan diet even for just one day a week will dramatically lower your carbon footprint- even more than eating 100% local foods.

Livestock consumes more than seven times as much grain as the entire human population eats. According to the U.S. Department of Agriculture, the food that U.S. livestock consumes would be enough to feed around 2.7 times the entire U.S. population if they simply followed a plant-based diet. If you are one of those people who hide behind the fact that you only eat meat from your local farmer (as if to justify participation in terror) Brazier shows, even eating local meat is simply inefficient. Brazier also answers the question about grass-fed beef. “If beef eaters in the United States were to switch to exclusively grass-fed beef,” argues Brazier, “one small steak about once every three weeks is all that would be available. There simply wouldn’t be enough to meet demand. And if more grazing land were to be created, of course deforestation would be the result.”[1]

These numbers speak volumes to me but at the same time, I do not want to suggest people should not buy local foods when they can. Rather, people should put an emphasis on always (or mostly) eating plant-based foods and supplementing their diets with local foods whenever possible. Especially as we move towards warmer months, farmers markets will be offering an increasingly large selection of farm fresh fruits and vegetables. Of course, cutting out that 11% will make a difference in your own carbon footprint and you’ll also be supporting local farmers and local economies, two good ideas from any perspective!

Unfortunately for meat eaters (particularly meat eaters who use the label “liberal” and supposedly care about these issues) this science is getting increasingly difficult to deny or ignore. The Inconvenient Truth that Al Gore doesn’t want us to know about, is no matter how many prius’ you park in the garage or energy efficient light bulbs you plug in, it doesn’t add to a hill of beans when compared to your food choices. There is a Convenient Truth, however. That is, eating vegan is delicious, healthy and easy.

Best wishes and health,

[1] Brazier, Thrive Foods 40.