Quantifying greenhouse gas emissions from global aquaculture

Global aquaculture makes an important contribution to food security directly (by increasing food availability and accessibility) and indirectly (as a driver of economic development). To enable sustainable expansion of aquaculture, we need to understand aquaculture’s contribution to global greenhouse gas (GHG) emissions and how it can be mitigated. This study quantifies the global GHG emissions from aquaculture (excluding the farming of aquatic plants), focusing on using modern, commercial feed formulations for the main species groups and geographic regions. Here we show that global aquaculture accounted for approximately 0.49% of anthropogenic GHG emissions in 2017, which is similar in magnitude to the emissions from sheep production. The modest emissions reflect the low emissions intensity of aquaculture, compared to terrestrial livestock (cattle, sheep and goats), which is largely due to the absence of enteric CH 4 in aquaculture, combined with the high fertility and low feed conversion ratios of finfish and shellfish.