Database results:
examBoard: Pearson Edexcel
examType: IGCSE
lessonTitle: Fish Farming Methods
Fish farming, also known as aquaculture, is the breeding, raising and harvesting of fish and other aquatic organisms in controlled environments. As wild fish stocks decline due to overfishing and environmental changes, fish farming has become increasingly important for meeting global protein demands.
Key Definitions:
Fish farming provides about 50% of all fish consumed globally. The industry has grown rapidly, with production increasing from less than 1 million tonnes in the 1950s to over 82 million tonnes today. As wild fish stocks continue to decline, aquaculture is becoming essential for food security.
Fish are an excellent source of high-quality protein, omega-3 fatty acids, vitamins D and B2, calcium and minerals like iron, zinc, iodine and magnesium. Farmed fish can help address malnutrition in many parts of the world where protein deficiency is common.
There are several methods of fish farming, each suited to different environments, species and scales of production.
Pond-based aquaculture is one of the oldest and most common methods of fish farming. These systems range from small backyard ponds to large commercial operations covering many hectares.
Low stocking density with minimal inputs. Fish feed mainly on naturally occurring food in the pond. Yields are lower but so are costs and environmental impacts.
Medium stocking density with some supplementary feeding and fertilisation to increase natural food production. Balance between inputs and outputs.
High stocking density with complete reliance on artificial feeds. Requires aeration systems and regular water quality monitoring. Higher yields but also higher costs and environmental impacts.
Cage aquaculture involves raising fish in floating enclosures in existing water bodies like lakes, reservoirs, rivers, or coastal areas.
Used in lakes and reservoirs for species like tilapia and carp. Cages are typically smaller and simpler than marine versions. They benefit from the surrounding ecosystem while containing the fish for easy management and harvest.
Located in coastal waters for species like salmon, sea bass and sea bream. These robust structures must withstand waves, currents and storms. Modern designs include submersible cages that can be lowered during bad weather.
Norway is the world's largest producer of farmed Atlantic salmon, using large-scale marine cage systems in fjords. The industry produces over 1.3 million tonnes annually and employs about 8,000 people directly. Norwegian companies have pioneered technologies like underwater cameras for monitoring fish behaviour, automated feeding systems and disease detection. However, challenges include sea lice infestations, which can spread to wild salmon populations and waste accumulation beneath cages. The industry is now developing offshore cages that can be placed in deeper waters with stronger currents to reduce environmental impacts.
RAS are land-based systems where water is continuously filtered and reused, creating a controlled environment for fish production.
In RAS, water flows through a series of treatment processes:
RAS offers several advantages including water conservation (using 95-99% less water than conventional methods), year-round production regardless of climate and minimal environmental impact. However, these systems require high initial investment, technical expertise and reliable electricity supply.
IMTA combines different species that benefit from each other, creating a mini-ecosystem that reduces waste and increases efficiency.
In IMTA systems, waste from one species becomes food for another. For example, a typical marine IMTA might include:
IMTA provides multiple benefits:
Rice-fish farming is an ancient practice in China dating back over 2,000 years. In this system, fish (typically carp species) are raised in flooded rice paddies. The fish benefit the rice by eating insects and weeds, while their movements aerate the soil and their waste fertilises the crop. The rice provides shade and habitat for the fish. This integrated system increases total food production from the same land area, reduces pesticide use and provides both carbohydrates (rice) and protein (fish) for local communities. In 2018, China had over 1.5 million hectares of rice-fish systems producing approximately 1.2 million tonnes of fish alongside rice crops. UNESCO has recognised traditional Chinese rice-fish farming as a "Globally Important Agricultural Heritage System."
As global demand for seafood continues to rise, fish farming will play an increasingly important role in food security. Several emerging trends are shaping the future of aquaculture:
The challenge for modern fish farming is to increase production while minimising environmental impacts and ensuring economic viability. With continued innovation and responsible practices, aquaculture can help meet the nutritional needs of a growing global population in a sustainable way.
Log in to track your progress and mark lessons as complete!
Login NowDon't have an account? Sign up here.