Fish Farming Techniques
Fish farming techniques have been cultivated by humankind for thousands of years because it is called fishing, not catching. We have gotten pretty good at it over the years but there is something to be said for the old ways which were much kinder to the environment. This article discusses some of the techniques in practice today and also touches upon some clever fish farming techniques from our past.
- Fish farming yesterday. The ancient Hawaiians loved their fish dinners and created fish farming techniques which are still being studied today. They would find places near the shoreline where fresh water springs from the mountain mingled with the ocean creating brackish ponds. They would construct a semicircular wall and seal it with a makaha or grate. During high tide, small fish would go through the grate and into the brackish pond where algae, seaweed and shrimp thrived. Low tide would trap them and they would grow too big to escape back through the makaha. Fish were harvested at leisure and the incoming tide always ensured a steady supply of food.
- Fish farming today. The fish farming techniques in practice today border on anything from sustainable to criminal. Some countries have fewer laws and fish farms are definitely created for profit. We see dangerous practices like using sewage runoff to create algae for stock food and then the fish are heavily dosed with antibiotics before they hit your plate. Luckily people have taken notice and offense to these techniques and things are starting to change.
- Recycled systems. Recycled or recirculated systems are ideal as fish farming techniques as they are heavily monitored and offer little to no environmental impact. The livestock is bred, raised and harvested in recycled water purified in treatment plants. The major drawback in this fish farming technique is the cost of water treatment which requires electricity and water purification technology.
- Raceway farms. Raceway fish farming techniques utilize a source of water like a creek or river and divert the flow into ponds. These ponds grow algae which is used to feed the fry. The ponds are connected to ensure a fresh supply of water for all levels of growth. This fish farming technique works well but the big drawback is the wastewater flows back into the primary source. While a river can easily handle a small fish farm, the commercial sized ones can wreak havoc. Plus there is a chance of the livestock, disease or parasites escaping into the primary source of water.
- Caged systems. One of the more popular fish farming techniques in marine environments is the cage system. Huge net cages are submerged and fish are reared in the confines. The nature of the sea ensures the water never grows stagnate. This is a huge advantage plus you can easily mix compatible species to increase your market reach. The drawbacks are the fish are easy to poach from humans and natural predators like sharks. Another drawback is the waste from the cages can possibly cause disease outbreaks. The impact not only affects the caged fish but also the native fish in the environment.
- Ponds. Ponds have been an age old favorite fish farming technique. Stock a pond with fry, let the fish grow and harvest. This practice can be organically simple if the local insects feed the fish in a small pond but it can also be incredibly destructive on larger scales. Catfish farmers in Kentucky trade sheer numbers for larger, better quality fish. Catfish farmers in China often practice the opposite philosophy and go for volume.