Many people believe that invertebrates like lobsters are not sentient and thus don’t feel pain. But research has shown just the opposite. Studies have looked at both nociception (“the ability to detect a harmful stimulus and to react to it reflexively”) and pain (“an aversive feeling or emotional experience”). Findings demonstrate that decapod crustaceans are sentient and should not be subjected to pain whenever possible. 

Professor Robert Elwood at Queen’s University Belfast has studied how to distinguish between nociception and pain. Nociception offers immediate protection from physical harm, whereas pain causes long-term protection. Signs of pain in decapods include “avoidance learning, physiological responses, protective motor reactions, motivational trade-offs, opioid receptors, and evidence of reduced pain experience when treated with anaesthetics or analgesics.” Elwood’s work suggests that decapods do feel pain.

Invertebrates have been much less studied than vertebrates, particularly in terms of their proper care. Lack of research is partly to blame for the incorrect belief that invertebrates don’t feel pain and don’t suffer. Decapod crustaceans, for instance, are not considered “animals” under any of the United Kingdom’s Animal Welfare Acts. Therefore, “retailers, processors and consumers are under no obligation to consider their welfare during storage, handling or slaughter.” Researchers have found that a lobster boiled alive can take up to three minutes to die and thus their pain and suffering must be better understood.

Other researchers have found that crabs appararently feel pain immediately after de-clawing and 24 hours later. Both vertebrates and invertibrates appear to “lick, rub or groom” a harmed body part. The European Food Safety Authority, in fact, classified all decapod crustaceans as Category One animals after reviewing the research because they “clearly … experience pain and distress.”

Analysts are starting to ask if the precautionary principle concerning pain should be extended to decapods. Of course, no one knows the mental state of another animal, but society may have enough evidence about lobsters’ sentience to receive legal protection. And should this protection be extended to all 15,000 decapod crustacean species (even if they haven’t been studied)? The precautionary principle advocates for the “benefit of the doubt.” 

In this study, the author investigated how lobsters were housed in tanks inside U.K. food stores in London and Brighton, England. Housing conditions of 325 lobsters were analyzed in four areas: restraints, tank density, lighting and shelter. Lobsters and their tanks were photographed for later analysis according to a husbandry welfare rubric.

All of the lobsters’ claws were restrained with rubber bands, presumably to prevent injury to other lobsters and human handlers. But lobsters inherently use their claws to aid movement, feed, and defend themselves. Additionally, all of the tanks housed lobsters together without private shelters. The more lobsters in a tank, the higher the chance for psychological stress. Artificial lighting also can cause stress because lobsters generally prefer darkness.

Overall, the data overwhelmingly indicates that outlets are not meeting the basic needs of lobsters and are essentially abusing them. The author recommends research on the welfare of lobsters and other decapod crustaceans, not only when housed in tanks, but also during trapping, handling and transportation to market. This should help with crafting new laws.

The author suggests future research, including investigating water quality (ammonia and oxygen levels), how noises in supermarkets affect lobsters, and how long on average lobsters live in the tanks. Other areas of study include trapping, shipping, and slaughter practices and how these influence lobster welfare. In fact, few countries give decapod crustaceans protection in their animal welfare laws. New Zealand, Norway, Switzerland, and some Australian states do provide some protections. Nations should revisit their welfare laws given new evidence about the sentience of invertebrates. For animal advocates, the paper highlights important areas of improvement in a context where significant change could be made.