The Growing Reality of Aquaculture

By Chris Mooney | January 22, 2010 10:49 am

aquacultureThis is the second in a series of guest posts by Joel Barkan, a previous contributor to “The Intersection” and a graduate student at the Scripps Institution of Oceanography. The renowned Scripps marine biologist Jeremy Jackson is teaching his famed “Marine Science, Economics, and Policy” course for what may be the last time this year (along with Jennifer Jacquet), and Joel will be reporting each week on the contents of the course.

Here in Southern California, we’re enduring an extended period of heavy rains and high winds, or as Floridians would call it, “July.”  People from harsher climates may laugh at our predicament, but the truth is that San Diego and its residents are ill-equipped to deal with rain.  Streets flood almost immediately because drainage is almost non-existent.  Traffic slows to the kind of crawl I experienced during white-out blizzards while growing up in Maine.

Most San Diegans know not to swim in the ocean during and after a storm.  The rain washes an assortment of chemicals, fertilizers, oil, and garbage straight down the hills and into the sea.  How would you feel knowing the fish you ate for dinner came from a farm that similarly inundated the surrounding waters with bacteria?  The discharge of waste is just one of many controversial issues concerning aquaculture, our most recent class topic here at Scripps.

Globally, aquaculture is the fastest-growing food production system, increasing by 8.8% per year since 1985, according to a 2007 report by the FAO.  Aquaculture already accounts for around one-third of global fish production and may soon rival wild-caught fisheries as our primary source for fish.  A shift to reliance on farmed fish could also lessen the burden on over-exploited wild stocks.  It’s difficult to talk about aquaculture without mentioning the growing human population:  simply put, we’re going to need more protein to feed an estimated 9.2 billion people by 2050.  Proponents of aquaculture call it a possible solution to our potential food crisis.

Unfortunately, aquaculture is not the silver bullet that will magically save us from overfishing and global food shortages.  Unless the farms are a closed system, effluent from fish pens will pollute the surrounding waters.  Escapees can transmit diseases to wild stocks—they become parasite-bearing fish on the lamb, terrorizing the innocent locals.  Plus, we need to catch millions of tons of wild fish, like the Peruvian anchoveta, to grind into fish meal to feed the farmed fish.  It’s like hunting seagulls off the coast of Africa and using the gull meat to feed chickens on a farm in Arkansas.  Despite these problems, we’re going to have to find ways to lessen the environmental impact of aquaculture as the industry continues to grow.

It was pointed out in class that a variety of U.S. government agencies regulate aquaculture, depending on where you are and why you’re doing it.  A good start to better management of aquaculture in our country would be to streamline the regulatory power to a single agency.  Then we can shift our focus to the rest of the world:  to China, to India, to Chile, and every other country hoping to feed its people with farmed fish.


Comments (11)

  1. There is already a great way to get around the waste water from the fish pens – its called aquaponics. Aquaponics is the integration of aquaculture and hydroponics where the fish effluent is converted through naturally occuring microbes into excellent, complete plant food. The plants in turn filter the water and cleanse it before returning to the fish tanks. Many people around the world are growing plants and fish together using this wonderful technique. Please contact me if you want to know more.

  2. David Wood

    The aquaculture industry does have it’s problems, but I defy you to find an agricultural industry that is more responsive to the concerns of the public than aquaculturists. Aquaponics, recirculating aquaculture systems, waste remediation, fish-meal replacement, and natural disease resistance are all avenues that researchers are focusing on to grow aquatic animals with little to no impact on the environment. Some public support would go a long way to expand sustainable aquaculture practices.

  3. gillt

    Speaking of aquaponics, I once worked on a project with cape cod cranberry farmers that overwintered freshwater game fish in pens in their cranberry bogs as an extra source of revenue.

    And lets not forget our favorite bivalves. Oyster grow-outs and clam beds have a positive effect on surrounding water by filtering it.

  4. GM

    How about doing something about reducing the population instead of just accepting that it will become 9-10 billion by 2050 and looking for more unsustainable “solutions”?

  5. That extra 3 billion people will also be rich enough to want to eat meat. That means that food conversion efficiency of our meat production systems is critical. Aquatic organisms don’t have to stand up or keep warm and, as a consequence, have inherently much better FCR’s (food conversion ratios — kg of dry feed/kg of produced animal). The FCR for salmon is about 1.0, chickens about 2.5 and pigs 3.5. Cattle are even worse but can utilize cellulose that the others can’t.

    The world has no choice, if we want to eat meat and don’t want to convert our little remaining wild areas into high intensity farms, other than increasing aquaculture. Especially open ocean aquaculture – that is where the water is. However, it appears impossible in the US and I recommend to anyone interested in investing aquaculture to look outside the US.


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About Chris Mooney

Chris is a science and political journalist and commentator and the author of three books, including the New York Times bestselling The Republican War on Science--dubbed "a landmark in contemporary political reporting" by and a "well-researched, closely argued and amply referenced indictment of the right wing's assault on science and scientists" by Scientific American--Storm World, and Unscientific America: How Scientific Illiteracy Threatens Our Future, co-authored by Sheril Kirshenbaum. They also write "The Intersection" blog together for Discover blogs. For a longer bio and contact information, see here.


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