Aquaculture or fish farming is the raising of fish and shellfish on special farms. Aquaculture can take place in the open ocean, in bays, in ponds, in greenhouses, and even in buildings.
In addition to preserving mummies and building pyramids, the ancient Egyptians were raising fish over 4,000 years ago. The Chinese also have a long history of fish farming. They raised a fish called a common carp because it was good to eat.
The Japanese raise a special type of fish similar to goldfish that can sell for thousands of dollars. These special fish are called KOI.
Many people raise koi as a hobby and they want certain colors and patterns. The colors may be white, black, red, orange, and grey. Sometimes the fish have shiny SCALES. Sometimes they have no scales at all.
In the United States, people started to farm fish so they could stock lakes and streams with fish for people to catch.
Some researchers are experimenting with raising fish in giant cages many miles offshore. The cages are equipped with cameras and computers so that scientists on dry land can see what is happening. FLOUNDER and COD are being raised in cages.
In Japan, oysters are farmed to produce cultured PEARLS. A tiny bead is placed in the oyster. The bead bothers the oyster so it produces a smooth shiny substance called NACRE over the bead. The layers of nacre that grow over the bead form the pearl.
Aquaculture is important because it provides high-quality, healthy food for your dinner, produces fish like TROUT and CATFISH to stock lakes and ponds for recreational fishing, and some shellfish, like clams, oysters, and mussels actually clean the water.
Clams, oysters, and mussels are important both because they taste good and because they help to keep the water clean. These animals are called filter feeders because they strain food out of the water.
If you ever visit the ocean, you might find an oyster shell that has other shells attached to it. Because oysters often grow together, they form habitats and hiding places for other animals. A HABITAT is a place to live.
Trout and catfish are both freshwater fish, but they live in very different habitats. Trout like to live in cold, clear, running water that has lots of oxygen (Remember, fish use their GILLS to take oxygen out of the water so they can breathe). Trout eat during the day. They eat insects, fish, and shellfish.
Catfish live on the bottom and like warm water. Because they often live in murky water, catfish have special “whiskers” called BARBELS that can help them feel around in the dark. That’s how they got their name. They have whiskers just like a cat. Catfish like to feed at night. They eat insects, small fish, and plants.
Fish farmers have to recreate those habitats so that their fish will grow. Trout are raised in spring-fed raceways where the water moves quickly through the system. Catfish are raised in ponds. Different types of aquaculture fish are fed different foods just like dogs and cats require different foods.