Your lobster bisque is almost as bad: The motors used to check lobster pots burn up a lot of gas. “Lobster has a terrible carbon footprint,” says Ray Hilborn, one of the researchers responsible for the study. On the other side of the scale were mollusk aquaculture — oysters, mussels, scallops, and clams — which are wonderfully efficient, and small wild fish, which don’t take much energy to gather up.
The methods used in the study were sound, and results line up with the findings of other studies, says Richard Waite, a food expert at the World Resources Institute, who was not involved in the research. However, this study didn’t consider the amount of land that different animals require, Waite notes.
About half the greenhouse gas emissions from agriculture come from farmers clearing forests. If you include the land needed to feed the animals, it significantly increases the emissions released in livestock production — making fish look better by comparison. And if you consider the type of land being cleared for farms, it downgrades the sustainability of shrimp farms in Southeast Asia. (It is possible to do shrimp farming right, as Amelia Urry found when she visited this cool shrimpery in Hawaii.)