Aquaculture, the farming of fresh or saltwater plants or animals, is a rapidly expanding industry, currently accounting for more than a quarter of global fish and seafood production.

The expansion and intensification of aquaculture has filled a significant gap in food production left by global declines in wild fish stocks (see EarthTrends map). Today, aquaculture operations are highly diverse enterprises, cultivating hundreds of different fish, crustacean, and mollusc species. Aquaculture production can be land- or water-based, and range from small, community farms to large-scale export-oriented industries.

Aquaculture has produced jobs, income, and food security for millions of people. However, there are also several environmental concerns associated with fish farming practices. Aquaculture requires the use of water and land resources, often in short supply, leading to water shortages and the loss of natural habitats. Nutrient inputs used in aquaculture can lead to harmful algal blooms and associated oxygen depletion in nearby waters. The use of antibiotic drugs or chemicals can pollute water supplies for both other fish and humans. Farmed fish that escape may cause disease outbreaks in wild fish populations or compete with wild populations for resources, impacting regional biodiversity. Finally, aquaculture also contributes to the depletion of wild fish stocks when ocean fish are used as fishmeal.

The WRI publication Fishing for Answers: Making Sense of the Global Fish Crisis provides a detailed analysis of the status of fisheries worldwide, including a discussion of the benefits and environmental concerns surrounding the aquaculture industry.

The Earthtrends feature "Farming Fish: The Aquaculture Boom" gives an overview of the aquaculture industry and its environmental impact.

The Earthtrends Coastal and Marine Ecosystems research topic includes data relating to both aquaculture and capture production. These data come from the Food and Agricultural Organization's (FAO) FISHSTAT database, and are also available in the State of the World's Fisheries and Aquaculture (SOFIA) report.

Also included in the EarthTrends searchable database are variables such as employment in fishing and aquaculture and annual food supply from fish and fishery products, which indicate the importance of fish and seafood to incomes and diets.

The Earthtrends map, "Natural versus Altered Landcover within 100 km of a Coastline" can be used to infer the impact of aquaculture on the world's coastlines.

A number of other online sources of aquaculture information are available, including FAO's national aquaculture factsheets and the Aquaculture Resource Directory.