Going fishing is one of the most popular pastimes in America. Going past this fact, commercial fishing is a big industry in the United States. However, more than likely, the fish you eat today will come from a fish farm. Fish farming is a form of aquaculture and it has stepped up to meet the demands of fish consumption. In 2006 the Americans ate an average of 16.5 pounds of fish per person.
Basically, fish farming is raising fish commercially in tanks or enclosures for human consumption. There are five typical methods of doing this. The first is the cage system where cages are placed in lakes, ponds and oceans. Referred to as offshore cultivation, this method artificially feeds and harvests the various species. The potential for fish to escape is the biggest concern for this type of operation.
Second is a unique system called the irrigation ditch or pond system. At a small level, fish are artificially fed and the waste that they produce is used to fertilize farmers’ fields. On a larger scale, mostly in ponds, the pond is self-sustaining as it grows plants and algae for fish food.
Composite fish culture allows local and imported fish species to co-exist in the same pond. Although the number varies, there are upwards of six species in one pond. In ecosystems like this it is especially important to make sure that the various species can co-exist and they do not compete for food.
Integrated recycling systems are the largest scale method of “pure” fish farming. Large plastic tanks are placed near greenhouse hydroponic beds. Water in the plastic tanks is circulated to the beds where fish waste goes to provide nutrients to the plant crops that are grown in the beds. The majority of plants grown in these beds are herbs like parsley and basil.
The fifth method of fish farming is classic fry farming, also known as “flow through systems.” Sport fish species are raised from eggs and then put in streams and released.
Some species are more conducive to being raised on fish farms than are others. The more common ones found on farms are salmon, carp, tilapia, catfish and cod.
Catfish are considered one of the most sustainable fish species of fish farming. They are popular because of their health benefits and market demand. They are easy to farm in warmer climates and are raised mostly in fresh water ponds and are fed corn, soybeans and rice.
Tilapia has increased in popularity due to their high protein content, large size and growth capabilities. They are tropical fish that require warmer water to survive. Because they reproduce rapidly, and are one of the most invasive species, they can be a challenge to raise. For this reason, males are used almost exclusively. On the plus side they do not eat other fish, but rather cereal, and are highly resilient in fighting diseases and parasites.
Salmon is one of the most popular fish species, with the most common farmed being Atlantic salmon. Coho and Chinook, two Pacific varieties, are also sought after. Prone to disease, they are routinely vaccinated to prevent outbreaks. The color of farm-raised salmon comes naturally from the food supply whereas wild-caught are dyed. They are also fairly expensive to raise since every pound of salmon produced requires 2 to 5 pounds of smaller fish for food.
Tuna, another popular variety, ranks near the top for importance in the commercial fish farming industry. Farming tuna is complex as the fish are massive and very active so simulating their natural environment is difficult. Most tuna for human consumption are caught wild and raised in a facility to increase weight gain.
Two factors affect how well a fish farm performs. Top of the list is feed quality. Depending on the type, feed can make a difference in color, growth and overall health of the fish. Ranking close behind is water filtration because it is important to remove waste products from the water.
With technological advances, indoor fish farming has become an important industry not only in the United States but also other countries. The advantages of indoor farming are: fish are protected from predators and weather changes; production is up because of temperature control, water quality and feeding practices; it is more environmentally friendly because less waste requires less water; less chance of fish escaping; and greater locality flexibility. The downside is that they use more electricity and the initial cost is high to set up the infrastructure.
So, if you are not a fisherman or the fish just plain aren’t biting, what is your best choice for consumption, wild-caught or farm raised? Depending on the kind, it can be a toss-up. Many chemicals that are banned in the United States are still used in international fish farms which mean we still eat them when we buy fish that are imported. Antibiotics and hormones are prevalent in farm-raised, whereas wild-caught has higher mercury levels and are leaner so the omega 3’s are lower in wild. The bottom line is wild-caught are probably more natural, but if you do choose farm-raised, choose American.
Due to overfishing, over 70% of the world’s fish are either fully exploited or depleted, thus, fish farming fills the gap. On a smaller scale, sometimes the little rascals just aren’t biting and you have a hunger for fish so you hit the store. Like this weekend, the guys had some luck one day out of three. Sorry, Ron and Scott, sometimes store-bought fills the bill.