Aquaculture is the practice of:

Fishing in the wild
Rearing fish in controlled environments
Processing fish
Exporting fish

The correct answer is: b) Rearing fish in controlled environments.

Aquaculture is the practice of raising aquatic organisms such as fish, crustaceans, mollusks, algae, and other aquatic plants in controlled environments. It is a subset of the wider aquacultural industry, which also includes marine farming, mariculture, and fish farming.

Aquaculture is a major source of food for humans, and it is also used to produce fishmeal and fish oil for animal feed. The global aquaculture industry is worth an estimated \$200 billion, and it is expected to grow by 5% per year.

There are many different types of aquaculture, including freshwater aquaculture, marine aquaculture, and brackish water aquaculture. Freshwater aquaculture is the most common type of aquaculture, and it is used to raise fish such as carp, tilapia, and catfish. Marine aquaculture is used to raise fish such as salmon, tuna, and shrimp. Brackish water aquaculture is used to raise fish such as tilapia and milkfish.

Aquaculture has many benefits, including:

  • It can help to reduce the pressure on wild fish stocks.
  • It can provide a source of food for people in developing countries.
  • It can create jobs in rural areas.
  • It can help to protect the environment.

However, aquaculture also has some challenges, including:

  • The use of antibiotics and other chemicals can pollute the environment.
  • The escape of farmed fish can damage wild fish populations.
  • The use of feed can contribute to climate change.

Despite these challenges, aquaculture is a sustainable way to produce food, and it is expected to play an increasingly important role in the global food system.

Here is a brief explanation of each option:

  • a) Fishing in the wild: This is the practice of catching fish in their natural habitat. It is a different activity from aquaculture, which involves raising fish in controlled environments.
  • b) Rearing fish in controlled environments: This is the practice of raising fish in tanks, ponds, or other enclosures. It is the main activity involved in aquaculture.
  • c) Processing fish: This is the practice of preparing fish for human consumption. It involves activities such as cleaning, filleting, and packaging fish.
  • d) Exporting fish: This is the practice of selling fish to other countries. It is a different activity from aquaculture, which involves raising fish in controlled environments.