Saraiva, Arechavala-Lopez, and Sneddon (2022) on Fish Farming

Joao L. Saraiva, Pablo Arechavala-Lopez, and Lynne U. Sneddon, “Farming Fish.” Chapter 10, pages 115-127, in Routledge Handbook of Animal Welfare, Andrew Knight, Clive Phillips, and Paula Sparks, editors, Routledge, 2022.

• First, a little background, drawing from the National Oceanic and Atmospheric Administration: aquaculture provides more than half of the seafood humans consume globally. Further, “The United States produced $1.5 billion worth of aquaculture seafood in 2018. The top U.S. marine aquaculture species were oysters ($219 million), clams ($122 million), and Atlantic salmon ($66 million).” About 75% of US seafood is imported, and about half of that is from aquaculture. In the US, aquaculture production by value is (only) about 20% of the overall seafood output. 

• "an estimated 51 to 167 billion farmed fishes were slaughtered for food globally in 2017 [p. 115]"; note that the number of land farm animals killed each year is on the order of 73 million. So farmed fish are multitudinous, and fish are sentient; nonetheless, little attention is focused on the welfare of farmed fish.  

• The technologies of fish farming vary considerably, and each method comes with its own welfare challenges. A traditional “land-based” form of fish farming involves the use of flooded rice paddies -- this method tends to not be particularly intensive. Other land-based options include the use of natural or artificial ponds, and higher technology versions such as flow-through tanks and raceways, sometimes with water recirculation.

• Water-based systems involve floating pens and cages but also confinement areas that must have water pumped in. 

• A few species of finfish (Atlantic salmon, rainbow trout, etc.) dominate aquaculture, along with shellfish.

• As with land animal farming, broodstocks are a key element of aquaculture. Some facilities use hatcheries and nurseries (land-based, closely controlled), and then the fish are moved to on-growing environments.

• Once again in parallel with land-based intensive animal farming, there are common welfare challenges for farmed fish. These challenges often are connected to high density and spatial restrictions. 

• Standard fish behaviors concerning reproduction, cognition, and emotions (fish have them!)  are generally compromised in aquaculture.  

• Other welfare challenges are connected to infections and parasites; stress and pain; water quality (which comprises many dimensions, including temperature, salinity, oxygen, pH, CO2, nitrogen); light (exposure to which is often highly artificial in aquaculture); and human handling and slaughter.