Nobody has any idea whether wild-caught fishing is good or bad

Update 1 Nov 2024: I’ve elaborated on this article in much more detail in a section of my upcoming book on wild-caught shrimp welfare.

Wild-caught fish interact with wild animals in ways that probably increase and/or decrease the amount of suffering happening. As such, catching wild fish could be bad, or it could be good, or it could vary depending on the context (though certainly not in ways that a supermarket shopper would be able to detect). There is extreme uncertainty here, due to the complexity of these interactions (which occur within-species and cross-species interactions). Beyond that empirical uncertainty, nobody really knows what the lives of most wild animals are like (in terms of subjective experience) or how to compare moral value across different species/phyla or different life-stages (Welfare Footprint, Rethink Priorities, and philosophers like Heather Browning are working on those philosophical/moral questions, but it’s still early days). I don’t really know how to think about this, and I don’t think anybody else does either.

Some people have thought about this, but it’s all very early-stage and underdeveloped. I still think it’s tentatively bad to eat wild-caught fish (as do some of the people who have thought about this - for full justification, read the key sources below in full), but this is an area we need to conduct more research on. Note that much of the fish sold in shops in the Global North comes from aquaculture, not wild-caught fishing, which is more obviously bad - the uncertainty only really applies to wild-caught animals.

Key sources:

• “The net impact [of fishing on suffering] is extremely unclear. Moreover, the sign of net impact may depend on what kind of fish is eaten—for example, catching big piscivorous fish may reduce zooplankton populations, while catching small zooplanktivorous fish may increase zooplankton populations.” How Wild-Caught Fishing Affects Wild-Animal Suffering (Tomasik)
• Fishing could decrease, or increase, the population sizes of other animals in the food web (e.g. those fishes’ prey, or zooplankton that compete with those fishes for food…). This could decrease, or increase, net animal suffering. We don’t really know. Trophic Cascades Caused by Fishing (Tomasik)
• Another article draws similarly uncertain conclusions. Should Fishing Opponents Be Happy about Overfishing?
• Another enormous uncertainty is how much moral value we place on zooplankton (and birds) compared to fish. Which Marine Trophic Level Contains the Most Total Suffering?
• Articles along similar lines from Michael St Jules: Sustainable fishing policy increases fishing, and demand reductions might, too; The responsiveness of aquatic animal supply
• I wrote a paper on the topic: Animal minds, social change, and the future of fisheries science

It’s interesting to me that the key sources are mostly blog articles, which I think is typical of very early-stage thought. There might be more peer-reviewed studies on this topic, but I haven’t seen them.