One hundred grams of farmed prawns can have a carbon footprint equivalent to burning 90 liters of gasoline, and 10 times greater than beef from deforested Amazon rainforests.
Many prawn farms in Asia and Latin America were established by destroying coastal mangrove forests. This harms birds and other wildlife, but also releases huge amounts of carbon captured in the soil of mangrove forests. Around 401 metric tons of of carbon goes into the atmosphere per hectare of mangrove forests cleared for farming (with around 1659 kilograms of prawns harvested during the average lifespan of a farm).
Researchers examined large and relatively inefficient prawn farms in southeast Asia, finding that the carbon footprint of prawn farming is higher than previously thought.