Fish farming is a hot topic in some circles. Environmentalists are often critical of the impact fish farms can have on the environment, while advocates point out that they're a crucial source of high-quality protein. Wherever you stand on that debate, one of the big advantages of fish farming is that it's a fine entrepreneurial opportunity.
Fish farming exists to address a fundamental problem: The demand for fish as a food source grows as the human population grows, and the number of fish available in the wild isn't keeping pace. Even in carefully managed wild fisheries, the combination of climate change, pollution and pressure from fishermen can produce unpredictable variations in the supply of fish. In a worst-case scenario, that can cause a fish population to crash, as Atlantic cod did in the 1970s and 1980s. In the long term, expecting conventional fisheries to continue to meet the world's needs with wild fish is as unrealistic as expecting a network of hunters to keep supermarket meat cases filled. Fish farming, or aquaculture as it's formally known, will need to make up the difference.
One of the basic principles of economics is that if demand is increasing and the supply is not, costs will go up. Over time, that trend could make fish unaffordable for all but the affluent. Bucking that trend is one of the biggest advantages of fish farming. By providing a steady, reliable, high-volume supply of fish, it helps the price remain manageable for most shoppers.
Having a reliable supply of fish is another advantage of aquaculture. The wild fishery fluctuates naturally, with catches rising or falling by the day, month or season. Fish farms turn out predictable harvests of fish at consistent sizes, making it easy for chefs, supermarkets, fishmongers and individual customers to plan their purchases. For restaurants and processors, this consistency means they can easily provide portions in standard sizes, too.
Another advantage of fish farming is that it brings the supply of fish to where the consumers are. From open pens in inland lakes to tanks and ponds on dry land, fish farms can be set up almost anywhere there's a market. This cuts the financial and environmental cost of shipping and provides consumers with fresher fish. That's a win-win.
Health authorities worldwide encourage more fish consumption, including the USDA's Dietary Guidelines for Americans, because it's a high-quality protein source that's low in saturated fat. Salmon has the added advantage of being especially high in omega-3 fatty acids, which promote heart health. Switching just a few meals per week from red meat to fish is not only healthier as a dietary choice, it's environmentally friendly as well: Fish farming is generally "greener" than meat production.
Another advantage of aquaculture is its potential to reduce the strain on wild fisheries and native fish stocks. The more fish farming meets our needs, the less incentive there is to purchase wild-caught fish. That in turn reduces the temptation to overfish and improves the likelihood that wild stocks can maintain a healthy population. Immature fish bred in captivity can even be used to re-establish species in places where they've been wiped out by overfishing.
However, one frequent criticism of fish farms is that they're not always efficient providers of dietary protein. Some operations rely on wild-caught "trash" fish or bait fish for much of their feed, meaning it's quite possible for the fish to consume more protein than they produce.
Unfortunately, fish farming also poses a risk to wild fish populations. Open-pen fish farms concentrate the creatures at unnaturally high levels, increasing waste and the risk of disease, just as many land-based hog and chicken farms do. This poses a threat to wild fish, which can be infected. Inland fresh-water systems can be just as harmful if they're located in a lake or river with its own wild species. Land-based systems that return used water to the local watershed also pose some risk. Escaped fish from these pens can become invasive, as fast-growing carp and tilapia do inland or farmed Atlantic salmon do on the West Coast.
One additional advantage of fish farming is that it represents an opportunity from which entrepreneurs almost anywhere can benefit. Farms can be situated anywhere from open coastlines to a farmer's "back 40" to a shuttered factory in a Rust Belt city. Startup costs can be surprisingly low for a small operation, largely a matter of choosing the right species to cultivate and providing a suitable environment. Salmon, trout, catfish, tilapia, shrimp and crawfish are all common options. Some operators maximize their productivity through composite fish culture, which is raising a combination of compatible, noncompetitive species in the same bodies of water. This gives you more variety in your product line and more fish to sell at little additional cost.
If you're looking for a decisive argument in favor of aquaculture, simple economics can provide one. The U.S. imports over 90 percent of its seafood, creating a yearly trade deficit that the USDA's Agricultural Research Service estimated at $14 billion as of January 2018. When you combine that economic impact with a fish farm's ability to fit in almost anywhere, the potential is clear: Fish farming can produce economic growth in places where jobs are sorely needed.
Managing a fish farm sustainably can help reduce its disadvantages and increase its advantages. For conventional open-pen operators, for example, that can mean reducing the populations of fish in each pen to cut down on waste and reduce the need for medications. On land, fish farmers can opt for recirculating aquaculture systems that filter and reuse the same water constantly, isolating the farmed fish from local waterways and minimizing the risk that they'll escape and become invasive. An especially appealing option is aquaponics, a method of growing vegetable crops such as herbs, lettuce and tomatoes hydroponically with the same water that supports the fish. Waste from the fish fertilizes the plants, which in turn helps filter the water and keeps the fish healthy.