The Effects of Farmed Fishing
Does the Economic Good outweigh the Geographic Harm?
Occasionally, there are stories of fish farming. Some are feel-good stories, others are feel-bad stories. Which is true? Is farming fish good or bad for people?
Fish Farming: The Basics
The economics of “farming” for fish differs slightly from beef, sheep, or corn farming. We associate farming with land-based activities. A system where humans own the land and provide the nutrients, environment, and ownership yields plant- or meat-based food.
Fish farming is very similar. Fish are raised in “pens” in the ocean. The water is freely changed by the ocean or rivers in the system. Like farming, operating this system was once very simple but has grown complex over time as the demands for output increase. the image above is from Iceland, where the pens are in the ocean and use tides and currents to change the water. The image at the bottom of the page is from Asia, where the pens are much closer and less water per pen is exchanged. These are often used for different types of fish than those raised in Europe of the United Staes.
There is also “raceway” farming. This is where the fish are raised in a trough or “raceway.” These farms will divert water from a canal, stream, or river into an artificial stream where fish are raised.
For our purposes, fish farming will be defined as raising fish in a man-made environment for food production. It is a very different system for acquiring fish for food than we in the West think of: raising them instead of catching wild fish. In a natural system, people would fish (the verb) in streams, lakes, and the ocean for fish (the food). For millennia, there has been small-scale farming by cultures using natural resources and keeping or stocking wild fish for use later as food. But this new “fish farming” is on an unnatural scale. Fish farming methods now use some contained areas – often open nets at sea – to keep fish from escaping. These farmed fish are so densely packed that they must use extra food and antibiotics to keep the large number of fish alive. In this sense, they are like factory-farmed pigs or chickens, which don’t live free on farms but are caged and used for food.
The use of fish farming has grown exponentially for years. Starting from 1950 or 1960, farmed fishing provided less than 3% of the world’s fish supply. In 2019, the amount of fish from farmed fishing exceeded that of wild-caught for the first time.
In the United States, we mainly import farmed fish, although we farm some catfish, salmon, trout, perch, and tilapia internally. We get 66% of our salmon, 90% of shrimp, and nearly 100% of tilapia and catfish from fish farms.
Benefits of Fish Farming
There are some very beneficial side effects from farmed fish.
It enables much more fish and protein to be available at a lower cost to people. Fish is the primary protein for tens of millions of people. Most cultures incorporate fish into their food systems where appropriate. Unlike pork or beef, almost no religions ban adherents from eating fish – although shellfish are different. Supporting many people at a low cost makes fish farming very attractive.
It decreases the pressure on natural fisheries. Most of us have heard of fish collapse in some systems. Off the coast of Canada and New England, the cod fish population dropped to almost zero from overfishing in the early 1990s despite catch limits on the population. In the early 1900s, the herring industry in Iceland collapsed because of overfishing. Neither region has recovered. Salmon fishing and hydroelectric facilities decimated the wild salmon populations in Washington and the Pacific Northwest. Farmed fish can be a solution to this issue by reducing the demand for wild fish from threatened ecosystems.
It reduces the cost and increases the availability of fish sold. Before large fishing fleets, most fish caught were for personal use or sold cheaply. Catching the fish was a low-cost but highly time-dependent activity. As fishing fleets cleared out easily accessible areas, subsistence fishing became much more difficult. Fishing fleets made fish more widely available but at the cost of overfishing and collapsing the food chain. As the cost increases, people switch to other foods, most of which are not as healthy as fish.
Fish farms do not significantly impact land use. The demand for land is constant. Urban areas often crowd out farmland. Much of the available land left over is inappropriate for farming due to the geography or lack of minerals. These issues can be corrected with fertilizer and herbicides, but these additives will run and cause pollution problems downstream. Fish farms, if done correctly, do not cause as much environmental damage.
Raceway fish farming
Drawbacks of Fish Farming
Like everything, fish farming also has drawbacks, some of which are severe. Like factory farming, fish farming is “unnatural” in the ecological system and can lead to unexpected results.
Fish farming puts greater demands on the water and increases pollution. Imagine thousands of fish, swimming in the sea with no problem. Now, put those thousands of fish in a floating enclosure in the water. The space will quickly fill with fish elimination and any dead fish. The water around the fish will degrade quickly.
Farmed fish depend on supplements to prevent disease and encourage growth. These are foreign introductions into the ecosystems. If these supplements are introduced into pens floating in the ocean, they will seep out into the more extraordinary ocean ecosystems with results we do not expect. These farmed and supplemented fish are now less “natural,” which can impact their nutrient value.
To feed farmed fish, large amounts of krill are necessary to keep a natural system in place. Fish have to eat something; the primary food source is the natural krill. To generate enough fish to make farming successful, krill or some replacement food source is necessary. This may lead to a reduction of krill in critical ocean areas, leaving some fisheries depopulated. Many farms use soy meal as food to avoid this issue.
If farmed fish get loose, they can interbreed with wild fish and reduce the viability of wild fish. For example, there are significant and mainly sustainable salmon farms in Iceland. In two cases, the farmed fish in ocean pens escaped through holes in the nets. These salmon escaped, and many mated with wild salmon. These hybrid fish grow faster than natural salmon but without artificial feeding dependent on men, they cannot consume enough food for viability. Hybrid fish have less natural immunity since farmed fish rely on antibiotics and human intervention. Introducing farmed fish can overwhelm a gene pool and cause a mass die-off. This can occur when the farmed fish introduce new diseases into the wild population. On a longer-term horizon, farmed fish / wild fish hybrids will shrink the gene pool for the species and may reduce their ability to thrive.
Farm-raised fish are often less nutritionally beneficial than wild-caught. They are still quite healthy and a great source of protein. However, farmed fish will have more fat because they don’t have to compete for food and are, therefore, more sedentary. Farmed fish don’t eat the variety of foods that wild fish do. So, their nutritional values may be different. On the other hand, farmed fish are less likely to have pollutants like mercury or lead that can be abundant in wild fish
Where does Fish Farming occur
The largest growers and consumers of farmed fish are in China and Southeast Asia. Here, fish farming has been an industry for hundreds of years. It has grown in importance and spread around Asia as the human population, and the demand for food has grown. In the last 75 years, fish farming has spread throughout the world. Farming fish is the largest segment of agricultural growth in the world.
Innovations
The idea of farmed fishing is excellent. Fish are a great source of protein and nutrients. Innovation is leading to ever-better systems to deal with the problems associated with the farms. Iceland and others are forcing water circulation to keep the fish healthier. But one of the coolest new ideas is indoor aquaponics.
From the website aquaponics.com, here is an explanation:
Today, aquaponics is not used extensively. But it is being adopted on a small scale, with great growth potential. Hydroponics, where crops are grown without soil, and fish farming combined can be done on a large scale. Hydroponics is already being widely, and adding the fish farming side of this will make it even more sustainable.
The Future
Fish farming will only grow. It is already more productive than animal farming, and as better methods come up (like aquaponics) this productivity will only increase. Let’s look at some basic costs. This data is pulled from asc-aqua.org.
1 pound Costs:
Salmon 1.3 pounds of canola seeds and 1.1 pounds of soybeans
Pork 2.5 pounds of soybeans and 5.5 pounds of cereals
Beef 2.5 pounds of soybeans and 10 pounds of cereals
Chicken 4 pounds of total feed
Fish is nutrient-rich and less harmful environmentally, so it will only grow in importance.
Now, if we only knew how to eliminate that fishy smell after cooking.