A new Worldwatch Institute report highlights the continued rise in aquaculture production and seafood consumption, with reference to their impact on the environment. The report shows that total global fish production, including both wild capture fish and aquaculture, reached an all-time high of 154 million tons (US tons) in 2011, and aquaculture is set to be more than 60% of production by 2020.
The report completed by the Worldwatch Institute (www.worldwatch.org) for its Vital Signs Online service shows that wild capture was 90.4 million tons in 2011, up 2% from 2010. Aquaculture, in contrast, has been expanding steadily for the last 25 years and saw a rise of 6.2% in 2011.
“Growth in fish farming can be a double-edged sword,” said Danielle Nierenberg, co-author of the report and Director of Worldwatch’s Nourishing the Planet project. “Despite its potential to affordably feed an ever-growing global population, it can also contribute to problems of habitat destruction, waste disposal, invasions of exotic species and pathogens, and depletion of wild fish stock.”
Humans ate 130.8 million tons of fish in 2011. The remaining 23.2 million tons of fish went to non-food uses such as fishmeal, fish oil, culture, bait, and pharmaceuticals, with aquaculture demands on fishmeal increase as the sector expands. Human consumption increased 14.4% percent over the last five years, while that of farmed fish surged 1000% since 1970, an average of 6.6% annually.
Asia is 66% of the total global seafood market for human consumption, and as the region’s wealth improves so does its rate of seafood consumption. This is having an impact on other regions where resource is gaining in value and competition for that resource is increasing.
Although Africa is only the fourth largest producer of fish in the world, its water resources are highly sought after by larger, more competitive fishing trawlers. Extreme overfishing occurs when foreign trawlers buy fishing licences from African countries for marine water use. In West African waters, foreign trawlers pose a threat because factory ships from the United Kingdom, other countries within the European Union, Russia, and Saudi Arabia can out-compete the technologies used by local fishers.
Compounding the wild supply problems, wild fish stocks are at a dangerously unsustainable level. As of 2009 (the most recent year with data), 57.4% of fisheries were estimated to be fully exploited, where current catches were at or close to their maximum sustainable yield. Of the remaining wild fisheries, 30% are overexploited, while a little less than 13% offer potential for expansion.
To maintain the current level of fish consumption in the world, aquaculture will need to provide an additional 23 million tons of farmed fish by 2020. To produce this additional amount, fish farming will also have to provide the necessary feed to grow the omnivorous and carnivorous fish that people want. Aquaculture is being pressured to provide both food and feed because of the oceans’ overexploited fisheries.
The report also identified that growth in the aquaculture sector was evenly spread between inland developments (6.2% increase to 44.3 million tons) and marine (6.6% to 19.3 million tonnes) but the sector remain dominated by inland aquaculture production using fresh water sources. Marine aquaculture, potentially the largest area for development, currently supplies just 30% of farmed seafood.
Asia continues to dominate global fish production, 121.3 million tons or 78.8% of the total. Europe is 2nd, its 16.4 million tonnes just 10.7%, but is slightly faster than Asia.
Continually increasing fish production, from both aquaculture and fisheries, raises many environmental concerns. If aquaculture continues to grow without constraints, it could lead to degradation of land and marine habitats, chemical pollution from fertilizers and antibiotics, the negative impacts of invasive species, and a lessened fish resistance to disease due to close proximity and intensive farming practices.