What’s Missing in Animal Welfare Efforts?

“Water Breathing Is a Blind Spot in Animal Welfare Science” (Issues, Winter 2026), by Jennifer Jacquet and Daniel Pauly, deserves to be read widely. The critically important points the authors make should change the way scientists approach the care and use of animals who breathe water and should spur protection of their habitats. Their observation that animal welfare science has historically centered on terrestrial, air-breathing species highlights a structural bias that animal law scholars have long urged the field to confront.

The lack of sufficient scientific inquiry into the needs and capacities of water-breathing animals creates harms beyond the impoverishment of the scientific field and has additional consequences that are also unseen. The omission of consideration of aquatic animals in many contexts illustrates how welfare standards can unintentionally exclude entire categories of animals when their biological needs differ from those of the species that inspired the framework. The legal system’s treatment of animals often reflects deep anthropocentric assumptions about which species’ experiences are cognizable under the law.

Because aquatic animals are often literally unseen, it falls to scientific, legal, and other professionals to raise them and their interests to the level of visibility. Thoughtful, intentional, and explicit consideration of the role these animals play on the planet, their needs and interests, and their capabilities is necessary in order to consider how and whether we should be interacting with or using them or impacting their homes and habitats.

The evolution of scientific thinking and study supports the development of other fields that rely upon this data, such as the legal field. When water-breathing animals are not deemed sentient, not thought capable of feeling pain or able to suffer from cognitive, psychological, or emotional harms, they can easily, and often legally, be treated without care in respect to these considerations. Once we have the scientific evidence, new legal questions arise about our responsibilities during our interactions with these animals.

Legal liability can vest if people knowingly cause harm or suffering in certain contexts. Knowing that aquatic animals can be harmed and can suffer creates new questions about legal liability. In the context of sport fishing, “catch and release” programs were created in response to critiques about killing animals for entertainment. The evidence Jacquet and Pauly share provides a basis for calling all of those programs into question based on harms that were not taken into account at their creation.

The proposal to expand welfare principles to include freedom from asphyxiation therefore represents more than a technical adjustment; it signals a broader shift toward acknowledging the distinct biological realities of trillions of aquatic animals. For animal lawyers and policymakers, incorporating such insights would help align legal standards with the best available science on sentience and suffering. Ultimately, addressing the welfare of water-breathing animals is not only a scientific imperative but also a legal and ethical one. Doing so reflects the evolving commitment within animal law to ensure that protections extend to all sentient beings, including those whose suffering occurs beneath the surface of the water.

Kathy Hessler

In Foray Into the Worlds of Animals and Humans: With A Theory of Meaning, the German biologist Jakob von Uexküll melded scientific rigor with, crucially, imagination to forge a more accurate understanding of a tick’s worldview. In the booklet, published in 1934 and translated in 2010, Uexküll takes up the tick as an exemplary foreign being whose perceptual world is radically different from that of humans—at once more limited (ticks have poor eyesight) and more expansive (ticks have enhanced olfaction for butyric acid)—to make the broader theoretical case that each species and each individual of each species lives within their own unique perceptual bubble. These perceptual bubbles, these umwelten in Uexküll’s terminology, serve as invisible filters: permitting in only a subset of information and blocking the rest.

Uexküll’s key insight—especially as it relates to Jennifer Jacquet and Daniel Pauly’s highly original article—is that umwelten shape experience so comprehensively that it can be easy to mistake personal experience for the entirety of reality. Reveling in the world I can see, that which is directly in front of me, it is difficult to experience the world behind me for what it is: an enormous blind spot. Unless and until imagination steps in, that is.

Jacquet and Pauly point out one such blind spot in animal welfare science and standards. And in fine Uexküllian tradition, they leverage scientific knowledge to make an imaginative leap: What might life be like for a water-breather?

Humans, like other endotherms, are air breathers whose metabolic function is mainly limited by an availability of food and water. For air-breathers hunger and thirst are, therefore, the primary shapers of subjective experience, driving motivation and setting emotional valence. For air-breathers oxygen availability is a nonissue, pointless to track and outside our perceptual bubbles. It is quite literally off our radar.

Not so for the multitudes of water-breathers. For fishes, crustaceans, and other aquatic organisms, oxygen availability is a main (if not the main) limiter to metabolic function and quite likely, therefore, to be an important determinant of their subjective experience. A small but growing body of literature covered by Jacquet and Pauly supports this inference: Deprivation from oxygen-rich water appears to be a source of severe pain and suffering for water-breathers.

What should animal welfare scientists and advocates do with this insight? The logic of the case is strong enough that further oxygen deprivation experiments are unlikely to benefit our knowledge base and are highly likely to come at great cost to the study participants themselves. Instead, the precautionary principle counsels the need to take action to update standards to minimize suffering from reduced oxygen availability across laboratories, farms, and fisheries operations. And, if we wish to forge a more accurate understanding of the water-breathers’ worldview, we may turn back to the imagination and wonder, what would delight a water-breather, how might oxygenation gradients shape their perceptual worlds, and what else might we be missing?

Becca Franks

Humans use fishes and other aquatic animals in a variety of ways, which makes our relationship with them rather complicated. Are they simply a “foodstuff” to be caught in vast numbers or farmed in captivity? Even the language we use to describe these animals tends to focus on demeaning them to the status of a stock or crop of plants. The term “harvest” is often applied to wild fish catch or when slaughtering them in aquaculture. Fishes are also used as a sport or recreational activity where the animals are caught using injurious hooks and can be released exhausted in the practice of catch and release. Fishes are now the second most used animal in science in Europe and other countries, and we subject them to invasive surgery, yet pain management is not common practice. Finally, we catch large numbers of fishes in the wild or breed them in captivity to become an exhibit in a public aquarium for human enjoyment, and fishes are the most numerous pets behind cats and dogs.

So when members of the public see a fish, do they think about a meal, an important experimental animal, or a beloved pet? Jennifer Jacquet and Daniel Pauly’s thought-provoking article raises many important questions about how fishes and other aquatic animals are treated. Since these animals live below water, we rarely see the vast numbers caught by commercial fishing or the treatment these animals experience in aquaculture. Out of sight can be out of mind. However, with the advent of underwater filming and public campaigns fueled by nongovernmental organizations and animal welfare charities, the harsh reality of the poor conditions that fishes can be subject to in wild capture and aquaculture is slowly coming to light.

As a scientist who has pioneered the study of pain in fishes and using scientific findings to inform the improved treatment of these neglected animals, I have come to believe that the public and government bodies need to realize that more funding is required to understand how welfare-compromising practices in aquaculture and fisheries truly affect the fish.

The unfortunate fact, however, is that without conducting experimental trials on these sentient beings that does include exposing them to poor welfare, then true progress cannot be made. From my experience of over 20 years, in order to revolutionize existing methods, one must have robust scientific data to drive changes in regulations and legislation as well as industry practice. The goal of these studies should be to identify a problem, then solve it with refined techniques that enhance welfare in fishes. For example, researchers have found that zebrafish subjected to common laboratory procedures exhibited adverse changes in behavior, but these were absent or could be reduced by providing them with pain-relieving drugs. This has led the Federation of European Laboratory Animal Associations to recommend that pain-relieving drugs must be used to improve the welfare of zebrafish subject to invasive procedures. This is just one species, and we now need to focus our attention on safeguarding the welfare of all aquatic animals used across all animal industries.

Lynne U. Sneddon

Jennifer Jacquet and Daniel Pauly make a compelling case that we have ignored the special harms suffered by water-breathers. I applaud their call for more relevant animal welfare science. While they mention that rising ocean temperatures and nutrient runoff into oceans will decrease oxygen levels, they focus mainly on captive water-breathers who suffer directly due to our actions, e.g., fishing and farming. Here I want to draw attention to the plight of wild water-breathing animals. Whereas the authors suggest that we have a duty to refrain from causing unnecessary suffering to water-breathers, I want to suggest that we also have a positive duty to help some in the wild.

Climate change and nutrient runoff are causing devastating oxygen declines in the world’s oceans, lakes, and estuaries. Areas with critically low oxygen levels can suffer die-offs of millions of benthic species from hypoxia, where insufficient oxygen reaches the tissues of the body. Moreover, the resulting algae blooms and habitat compression that occur in these hypoxic zones indirectly cause more harms, both to individuals and the ecosystems themselves. Should we help relieve this suffering?

For decades conservationists have debated whether we have ethical obligations to reduce the suffering of animals in the wild. Should we rescue prey from predators? Vaccinate animals from disease? Help animals fleeing from wildfire? Many of these discussions pit concerns about animal welfare against those for healthy ecosystems. Some observers argue that we do not have duties to help animals in the wild unless we caused the suffering. Others point to the practical intractability of the problem, arguing that interventions would often backfire ecologically, resulting in more rather than less animal suffering.

However, in some cases we can clearly help without getting into deep philosophical waters. Suppose a coastal estuary is seasonally blocked from the ocean due to sand buildup. Oxygen may predictably deplete to levels that can cause hypoxia. Yet a mobile aerator could be deployed to bridge this episode and save thousands of animals lives and reduce suffering. Artificial aeration is a proven cheap and effective method to reduce mortality spikes. Although it is employed in thousands of lakes and other locales, it is a vastly underutilized resource—presumably in part due to the blind spot the authors identify. And unlike rescuing prey, this welfare intervention into the wild should be relatively uncontroversial. Typically hypoxia is caused by human activity and maintaining oxygen aligns with keeping ecosystems healthy.

Of course, these and similar interventions (e.g., microbubble generators and stratification pumps) are not scalable to the ocean at large. For hypoxia in large bodies of water, the suffering of water-breathers simply adds moral urgency to the ethically already-pressing requirement to mitigate climate change and nutrient runoff. And where artificial oxygenators work, even still they are usually “band-aids” that temporarily treat symptoms and not causes. But sometimes, I submit, band-aids are worthwhile. Their placement may prevent the suffocation of individual animals as we try to make the bigger changes to keep their ecosystems livable.

Fish die-offs strike us as horrible partly because they are one of the rare times water-breathers spontaneously become visible to we air-breathers. But we ought not let the water’s surface hide our moral responsibility to alleviate the almost unimaginable amount of suffering caused in these living creatures by hypoxia.

Craig Callender