Not eating fish is a pretty simple way to help prevent unsustainable fish depopulation. I'm a bit incredulous that anyone would argue this point. Anyone other than individuals who want to rationalize their current destructive habits.
> Most experts say that DHA and EPA -- from fish and fish oil -- have better established health benefits than ALA. DHA and EPA are found together only in fatty fish and algae. DHA can also be found on its own in algae, while flaxseed and plant sources of omega-3s provide ALA -- a precursor to EPA and DHA, and a source of energy. [1]
Fish are healthy and good for us. One of the primary causes of overfishing is caused by our unhealthy fascination for tuna. There are many sustainable sources of fish which are available (such as trout); our society's desire for one that is so inefficient in bulking up does not mean you should give up on fish entirely as a result.
[1] http://www.webmd.com/healthy-aging/omega-3-fatty-acids-fact-...
It's easier to rationalize your existing behavior than it is to change it. But instead of changing it, maybe just make the cognitive effort to recognize the wrongness. This requires no behavioral change, just an attitude change. If you do this, after enough time behavioral change comes easier. In other words detach reasoning about the ethics of the behavior from the work involved in optimizing your life.
"All I can do is change my behavior. I can't change the behavior of hundreds of other people as much as I would want to."
Well, millions, I assume you mean.
"make the cognitive effort to recognize the wrongness."
I think you're assuming my conclusion. :)
Meat contributes far more of a negative impact on the environment than plants though. Consider the fact that it takes 8 lbs of grain to produce 1 lb of beef[1]. That's absurdly wasteful in the quantities of beef that most American's eat weekly.
[1]: http://alumni.stanford.edu/get/page/magazine/article/?articl...
Also, it's worth remembering that we get a lot more than just meat out of your average cow. We get medicines, leather, meat, fertilizer, gelatin, and pet feed. In fact, the ~40% of the cow which is left after butchering is rendered down into a streams of protein and fat for secondary uses, resulting in zero waste of the animal.
There are simply a lot of things you use day to day which come from those cows and those 8 lbs of grain...
http://opinionator.blogs.nytimes.com/2012/05/15/we-could-be-...
>It takes 100 times more water (up to 2,500 gallons) to produce a pound of grain-fed beef than it does to produce a pound of wheat. We’re also running out of land: somewhere around 45 percent of the world’s land is either directly or indirectly involved in livestock production
http://www.scientificamerican.com/article/the-greenhouse-ham...
>the meat [in our diets] cause more greenhouse gases carbon dioxide (CO2), methane, nitrous oxide, and the like to spew into the atmosphere than either transportation or industry.
http://www.nytimes.com/2008/01/27/weekinreview/27bittman.htm...
>Global demand for meat has multiplied in recent years, encouraged by growing affluence and nourished by the proliferation of huge, confined animal feeding operations. These assembly-line meat factories consume enormous amounts of energy, pollute water supplies, generate significant greenhouse gases and require ever-increasing amounts of corn, soy and other grains, a dependency that has led to the destruction of vast swaths of the world’s tropical rain forests.
>Just this week, the president of Brazil announced emergency measures to halt the burning and cutting of the country’s rain forests for crop and grazing land. In the last five months alone, the government says, 1,250 square miles were lost.