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Too Few Fish in the Sea
For me, giving up fish was the toughest part about becoming vegetarian. Asking me to eschew sushi might as well have been, “Would you like to have your brains tenderized with a steel mallet?” In fact, for several years, I floundered in that amphibious realm called pescetarianism, or pesco-vegetarianism, where you allow yourself to include seafood in your diet, which scientific circles might call TRYING-TO-HAVE-YOUR-CAKE-AND-EAT-IT-TOO-ISM, COP-OUTISM, or ARE-YOU-SERIOUSISM. But its no secret that our ocean populations are facing an enormous crisis, taxed as they are by overfishing and habitat destruction. According to a study reported by Reuters, the world’s fish and seafood populations will “collapse” by 2048 if current trends persist, resulting in catch reductions of 90 percent and leaving less seafood for fish-lovers everywhere.

This applies to all species, from mussels and clams to tuna and swordfish, said Boris Worm, lead author of the study, which was published in the current edition of the journal Science.

Ocean mammals, including seals, killer whales and dolphins, are also affected.

“Whether we looked at tide pools or studies over the entire world’s ocean, we saw the same picture emerging,” Worm said in a statement. “In losing species we lose the productivity and stability of entire ecosystems. I was shocked and disturbed by how consistent these trends are—beyond anything we suspected.”

[via Rustle the Leaf]

Beyond seafood, human health risks emerge as “depleted coastal ecosystems become vulnerable to invasive species, disease outbreaks, and noxious algal blooms,” according to the nonprofit organization SeaWeb in a press release about the study.

Many of the economic activities along our coasts rely on diverse systems and the healthy waters they supply. “The ocean is a great recycler,” explains [study co-author Steve] Palumbi [of Stanford University], “It takes sewage and recycles it into nutrients, it scrubs toxins out of the water, and it produces food and turns carbon dioxide into food and oxygen.” But in order to provide these services, the ocean needs all its working parts, the millions of plant and animal species that inhabit the sea.

Brain Food or Brain Poison?
Less transparent, however, is the contention about whether the benefits of fish (due to their omega-3-fatty-acid content) outweigh the risk of ingesting contaminants such as mercury, PCBs (polychlorinated biphenyls), and dioxins, which can be found in high concentrations in fish such as farmed salmon. (Generally, the higher up a fish is in the food chain, the higher its concentration of toxins.)

In the pro-fish corner is The American Heart Association, which recommends eating fish twice a week. The U.S. Food and Drug Administration, on the other hand, cautions young children and women who are nursing, pregnant, or planning to become pregnant to avoid some types of fish and limit themselves to seafood low in mercury. According to the U.S. Environmental Protection Agency, mercury can “adversely affect a baby’s growing brain and nervous system,” including impacts on cognitive thinking, memory, attention, language, and fine motor and visual spatial skills.

Outbreaks of methylmercury poisonings have made it clear that adults, children, and developing fetuses are at risk from ingestion exposure to methylmercury. During these poisoning outbreaks some mothers with no symptoms of nervous system damage gave birth to infants with severe disabilities, it became clear that the developing nervous system of the fetus may be more vulnerable to methylmercury than is the adult nervous system. …

In addition to the subtle impairments noted above, symptoms of methylmercury poisoning may include; impairment of the peripheral vision; disturbances in sensations (“pins and needles” feelings, usually in the hands, feet, and around the mouth); lack of coordination of movements; impairment of speech, hearing, walking; and muscle weakness.

The Case for Omega-3
The intake of the omega-3 fatty acids found in fish, however, has been linked to a lower incidence of heart disease, lowered cholesterol and other blood-fat levels, and a slight reduction of blood pressure. Fatty fish may even slow very early Alzheimer’s or protect against prostate cancer. There are even nutritionists who say that we are suffering from a deficiency of omega-3 in modern diets, because they’re being flooded out by competing omega-6 fatty acids, mainly from industrial oils such as soy, corn, and sunflower. Our ancestors were used to diets with balanced amounts of omega-3 and omega-6, but poor eating habits today have led to an imbalance where there is too much omega-6 and not enough omega-3.

According to The Guardian:

In the US, for example, soya oil accounted for only 0.02 percent of all calories available in 1909, but by 2000 it accounted for 20 percent. Americans have gone from eating a fraction of an ounce of soya oil a year to downing 25lbs (11.3kg) per person per year in that period. In the UK, omega-6 fats from oils such as soya, corn, and sunflower accounted for 1 percent of energy supply in the early 1960s, but by 2000 they were nearly 5 percent. These omega-6 fatty acids come mainly from industrial frying for takeaways, ready meals and snack foods such as crisps, chips, biscuits, ice-creams and from margarine. Alcohol, meanwhile, depletes omega-3s from the brain.

The same article also suggests that too much omega-6 (and, conversely, too little omega-3) is responsible for rising violence and aggression. There are also claims that fish oils could help emotionally disturbed children. (Some scientists insist we need more research into the possible side effects of using omega-3 to treat mood disorders, however.) Another reason for moms-to-be to load up on omega-3: brainer babies.

If you like eating fish, you might like to download and print The Green Guide’s Smart Shopper’s Fish Picks to keep in your wallet. Divided into three categories, Yes fish have low mercury and are not farmed destructively, Sometimes fish are recovering populations or contain moderate concentrations of mercury, and No fish are absolute no-nos because they are overfished, farmed destructively, or have high levels of mercury.

Fish-Free Fish Oil
If you take into account the toxic impurities found in fish, taking fish-oil supplements could be a safer way of getting your omega-3, but only if the oil has been purified properly. (Environmental Defense did our homework for us by evaluating 75 different brands of supplements available.) In Europe, heart-attack patients are routinely sent home with prescriptions for purified fish oil. (In fact, it could be considered malpractice in Italy to omit the drug.)

For Vegetarians
There are 3 kinds of omega-3: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). ALA is a plant-based omega-3 that can be found in foods such as flaxseed and walnuts. In order to reap the benefits of omega-3, your body must convert ALA to EPA and DHA, and so, higher amounts of ALA-rich foods must be consumed to get the same boost as taking fish oil directly. (The conversion process is dependent on having enough vitamins B3, B6, and C, magnesium, and zinc; trans-fat could impede the conversion.)

Still, flaxseed is a good alternative for vegetarians and vegans, particularly because they are also a source of protein. Besides the exceptional qualities of omega-3, flaxseed also provides a good source of fiber that can lower cholesterol levels in people with atherosclerosis and diabetic heart disease, reduce the risk of developing colon cancer, help relieve constipation, and stabilize blood sugar levels if you have diabetes. Lignins, which are a phytonutrient, found in flaxseed may also protect against breast cancer because they seem to flush excess estrogen out of the body.

The best way to consume flaxseed is to buy the seeds whole and then grind them with a coffee or spice grinder into a fine meal for immediate use. (Flaxseed oil needs to be refrigerated and doesn’t have the same protein, fiber, vitamins and minerals, and lignins you’d find in the seeds. Don’t use it in cooking because the heat can convert the good fats into bad ones.)