Industrial-Scale Aquaculture Intensifies Greenhouse Gas Emissions

Researchers in China, South Korea and the UK have demonstrated that the rapid increase in aquaculture activities is associated with elevated greenhouse gas emissions.

AsianScientist (Mar. 26, 2019) – An international team of scientists has determined that the adoption of industrial-scale aquaculture is linked to rapid increases in greenhouse gas emissions. Their work is published in the journal Nature Climate Change.

Between 1961 and 2016, the average annual increase in global food fish consumption outpaced population growth and exceeded that of meat from all terrestrial animals combined. Global capture fisheries have leveled off since the 1980s, and aquaculture has been responsible for the continuing growth in the supply of fish for human consumption.

However, the rapid development of aquaculture is often accompanied by a shift in land use patterns. For instance, more than half of Chinese freshwater aquaculture ponds are reported to be converted from paddy fields. Changes in land use patterns may change the intensity of greenhouse gas emissions, but the potential impact of this process is unclear.

In the present study, a research team led by Professor Ding Weixin from the Institute of Soil Sciences at the Chinese Academy of Sciences, in collaboration with colleagues in the UK and South Korea, conducted a field study in the Taihu Lake basin to explore the greenhouse gas costs of converting paddy fields to extensively managed crab culturing ponds.

The researchers found that such conversion contributed towards global warming primarily due to increased methane emissions. They also established the emission factors of methane and nitrous oxide for different types of aquaculture systems, developing a global inventory for greenhouse gas emissions from major producers. They estimated that the global top 21 producers accounted for 1.82 percent and 0.34 percent of global anthropogenic methane and nitrous oxide emissions, respectively.

However, the researchers pointed out that methane emission from intensively managed aquaculture systems was negligible because of continuous aeration. Therefore, if half of current aquaculture production from extensive plus semi-intensive systems is replaced by intensive systems, methane and nitrous oxide emissions from freshwater aquaculture could be reduced by 40.1 percent.

Their findings further indicate that more efficient aerators in earthen ponds and optimized feeding strategies are urgently required to mitigate greenhouse gas emissions and reduce pollution from the unprecedented growth of aquaculture, as well as improve the economic efficiency of industrial-scale aquaculture.

The article can be found at: Yuan et al. (2019) Rapid Growth in Greenhouse Gas Emissions From the Adoption of Industrial-scale Aquaculture.


Source: Chinese Academy of Sciences; Photo: Pixabay.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist