This 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.