Overfishing: One Fish, Two Fish, Soon Too Few Fish

by Jean Alves

It’s a rare phenomenon – the amicable meeting of the minds between the public-health and culinary worlds.  Of all foods, fish may be the greatest exception to the general rule that people don’t want to eat what’s good for them.   Just in the past decade, omega-3’s became the big buzz word among health professionals, sushi became supremely chic, and salmon started to spruce up menus.  Seafood turned “superfood”, and fish got sexy.

Today, Americans eat an average of 16 pounds of seafood a year, 25% more than they did 20 years ago, and the fishing industry has enjoyed a 70% increase as a result – that’s 2 billion pounds of additional fish a year.  Yes, fish is tasty and healthy.  Life is good.  Thank goodness our oceans are an inexhaustible resource!


Sadly, of course, the world’s oceans provide only a finite amount of fish, and we, as a global community of seafood eaters, are rapidly overfishing to the point of total extinction.  Scientists predict the total collapse of all fished species in less than 50 years.   For every 10 tuna, sharks, and other large predatory fish that were in our oceans 50 to 100 years ago, only one remains.

Modern-day fishing technologies have enabled us to find, catch, and kill anything that swims or scuttles.  Radar, echo sounders, Navy-developed electronic navigation systems, and satellite-based GPS allow for more effective and efficient catches than ever before, typically by longline or purse seine fishing or trawling.

Take tuna, for example, the world’s most popular fish thank, in large part, to the booming sushi industry.  Today’s tuna is almost never caught with traditional “pole and line” equipment.  Oftentimes, longlines are used in tuna fishing.  Longlines are just that – really long lines (they can be as long as 75 miles long, a distance equal to that from sea level to space) with smaller branch lines riddled with hooks reminiscent of wirey cactus tendrils.  An estimated 27 million longline hooks are deployed every day, an unsustainable practice which has reduced bluefin tuna stocks to as low as 5% of their natural levels.

And longlines don’t just kill their target species – 145 other sea species are caught and killed inadvertently in the hunt for highly demanded tuna.  One study found that roughly 4.5 million sea animals are killed as bycatch in longline fishing every year, including about 3.3 million sharks, 1 million marlins, 60,000 sea turtles, 75,000 albatross, and 20,000 dolphins and whales.

Shrimp trawling offers another prime example of the unconscionable, let alone unsustainable, nature of modern fishing.  Trawling is even more damaging than longlines; the most common type of modern shrimp trawler sweeps an area roughly 25 to 30 meters wide as it sweeps fish (and everything else) into the far end of a funnel-shaped net.  It has been described as the marine equivalent of clear-cutting rain forest.  Whether trawling for shrimp or another target species, these enormous nets sweep up fish, sharks, rays, crabs, squid, scallops – typically about 100 different fish and other species in one big scoop.

Virtually all that are picked up die.  The average trawling operation throws 80 to 90% of the sea animals it captures as bycatch overboard.  The least efficient operations actually throw more than 98% of dead bycatch back into the ocean.  Astonishingly, while shrimp account for only 2% of global seafood by weight, shrimp trawling accounts for 33% of global bycatch.

Thus, our oceans simply cannot supply enough to satisfy our voracious appetites nor compete with our merciless fishing methods.  Clearly, an alternative is desperately needed.


While aquaculture may seem like a logical and viable answer to the problem of over fishing, it too is a system fraught with problems.  No different than land-based CAFOs, open ocean aquaculture (OOA) or “offshore aquaculture” involves cramming thousands of potentially high-value fish, such as cobia and cod, into large cages in U.S. federal waters between three and 200 miles from shore, often polluting the surrounding marine ecosystem with fish waste, excess fish feed, and chemicals at the expense of the marine environment, human health, wild fish populations, and local fishermen and coastal communities.

From an ecological standpoint, the dredging, drilling, and other sediment and bottom-habitat disturbances involved in creating and maintaining giant offshore fish farms can cause serious damage to the water and wildlife around them.  Seagrass and coral die off and other ocean animals become displaced.  In addition, farm-raised fish may pose a threat to endangered or otherwise vulnerable species.  Because such species have already become genetically different and weaker than their natural population state, escapement or intentional addition of farmed fish could completely change the integrity of the wild population’s gene pool.  Ocean fish farming facilities are often subject to uncontrollable conditions including extreme weather conditions, disease, and human precision. Facility damage by any number of unplanned events (violent storms, hungry predators, human error) could cause a major escape or significant chemical pollution.

And what about the “intentional addition” of farmed fish?  Indeed, ocean fish farming operations are often developed for programs to re-stock natural populations in decline.  However, cultured animals can look or behave differently than wild ones because of their captive conditions and may even be genetically different because they were raised to grow faster and larger.  They may not have the ability to feed, reproduce, and survive in the wild, and intentionally adding cultured animals to wild populations can, over time, change the genetic composition and behavior of natural stocks completely altering natural roles and relationships within the ecosystem.

Unnaturally cramped conditions that cause higher stress than in the wild make farmed fish prone to diseases and parasites, which are then treated with antibiotics, pesticides, and other chemicals. As with land-animal factory farming, the rampant spread of diseases among the animals calls for the use of antimicrobial agents, which leads to the creation of drug-resistant bacteria that may directly transfer to human consumers.  Both the diseases and chemicals can be transmitted beyond the fish farm to wild fish through the open-net pens.  Some of these chemicals are seriously damaging and even lethal to other species; the pesticide used to in the treatment of sea-lice infestation, a common and cruel problem among crowded fish farms, can actually kill shrimp and lobsters.

These chemicals, which apparently affect not just farmed fish but exposed wild fish as well, are also known to be potentially dangerous to humans.  The Food and Drug Administration (FDA) classifies drugs as “high regulatory priority” or “low regulatory priority”.  Two drugs used in the aquaculture industry, copper sulfate and potassium permanganate, have had their status deferred pending further study.  Despite the fact that copper sulfate can cause liver and kidney damage, and potassium permanganate can cause nausea, vomiting, abdominal pain, and kidney problems in humans, there are currently no set standards for their use, and aquaculture operators use them freely.


Though the current fish situation may seem bleak, consumers have some sustainable seafood choices.  First of all, you can find and download pocket-sized fish guides from a host of reputable online sources.  Check out the guides at Food & Water Watch, Monterey Bay Aquarium’s Seafood Watch, or Greenpeace.  Some of the safest choices include Alaska wild salmon and pollock, farmed mussels, oysters, and clams, and Pacific halibut.

Rob Cushman, 2nd year Agriculture, Food and Environment student is committed to supporting small-scale fisherman while still making responsible seafood choices.  Small-scale fisheries are both more environmentally and economically responsible than large-scale fishing operations.

Both large- and small-scale industries catch about the same amount of fish – 30 tons annually – for human consumption, yet while the former requires about 37 million tons of fuel oil per year, the latter uses less than one sixth of that amount.  The small-scale industry also employs 24 times as many fishers, and accounts for very little discarded bycatch, whereas large-scale fisheries throw back between eight and 20 tons of dead marine wildlife every year.

In addition to supporting local, small-scale fishers, Cushman emphasizes the importance of eating more bottom-feeder fish.  “I am and avid consumer of fresh, pickled, and canned sardines – we need to eat forage fish directly instead of feeding them to industrial chicken/pork and our pets – oysters, mussels, clams, and seaweed,” explains Cushman, adding “Mollusks and Seaweed are the ultimate win – win – win.  They are nutrition powerhouse, make organic land farming look energy intensive, and provide excellent ecological services.”

Although some of the most sustainable seafood choices may seem a bit alien and intimidating at first, Cushman insists that after doing a little homework, you’ll find lots of easy and delicious recipes.  “I used to love sushi; now I think it’s dirty word.  I now  like my seafood choices better than before.  It has forced me to be more creative and adventurous with seafood further down the food chain.”

You may also choose to join a Community Supported Fishery (CSF).  A new wave on the sustainable fishing front, CSFs are helping reconnect consumers to the ocean and small-scale local fishermen.  Local to Boston, the Cape Ann CSF provides its members with generous helpings of a variety of seafood.  “The people who delivered [the catch] were great” says Emily Kuross, PhD candidate, Food Policy and Applied Nutrition.  “And, in this new season, they’re offering already-filleted fish.”  While filleted fish are more expensive than the fish purchased whole, Kuross admits that the extra charge is probably worth it, since gutting your first fish can be intimidating and, well, stinky.

Though making the commitment to switch to a sustainable seafood diet can be challenging, Kuross finds that it’s ultimately more meaningful and enriching.  “Overall, I don’t find making moral/ecologically responsible fish choices difficult, per se, I just sometimes find it limiting.  But that’s  just a fact of life when you’re trying to make better choices.  They’ll be more limited, but I don’t think that’s a bad thing, and it certainly doesn’t make me feel deprived in any way…if we’re careful about our choices we can, in a
sense, have our fish and eat them too.”

Apart from encouraging environmental stewardship and supporting the viability of the local coastal economy, CFSs also cultivate ties and establish bonds between shore-side communities and those living inshore in urban, suburban, and rural areas.  To support marine conservation and the survival of the local seafood industry, consider participating in the next season of Cape Ann’s Fresh Catch CFS beginning in May.  Visit http://namanet.org/csf/cape-ann-fresh-catch for more information.

The Friedman Sprout is a monthly student run newspaper that aims to serve the student population at the Friedman School of Nutrition Science and Policy, prospective students, and alumni. Our mission is to report on newsworthy information that affects the Friedman community including nutrition research, food policy, internship and volunteer opportunities, as well as school events. Our editorial slant is that of sustainability in food and nutrition.

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