Note: This post originally appeared in the monthly farm animal welfare newsletter written by Lewis Bollard, our program officer for farm animal welfare. Sign up here to receive an email each month with Lewis’ research and insights into a farm animal advocacy research topic. We decided to cross-post this one because we thought it was especially interesting and wanted to make people aware of Lewis’ newsletter, but note that the newsletter is not thoroughly vetted by other staff and does not necessarily represent consensus views of the Open Philanthropy Project as a whole.
When we think of farm animals, we likely don’t think of carp. But this family of freshwater fish — which includes the three most populous farmed fish species in the world: crucian carp, silver carp, and catla — is likely the most numerous farmed vertebrate animal in the world, with an estimated 25-95 billion farmed every year. (About 62 billion chickens are farmed every year, but each is farmed for just 5-8 weeks, whereas carp are farmed for 12-14 months, meaning far more carp are alive at any given time.)
Fish are the forgotten farm animal. Of the more than 100 undercover investigations that U.S. animal advocates have done to expose abuse of farm animals, just one focused on fish. For a long time scientists questioned if fish could feel pain, though our internal investigation suggests there’s about as much evidence for some fish being able to feel pain as there is for birds.