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Animal Welfare - Recent Reports and Comments

Animal Welfare vol 24 issue 1 Volume 31 
Issue 1
February 2022




Review of the evidence of sentience in cephalopod molluscs and decapod crustaceans

All cephalopod molluscs and decapod crustaceans should be regarded as sentient and protected under UK animal welfare law. This is the headline conclusion of this thoughtful report, that is going to have a profound impact on the way these animals are treated within the UK — and likely inform policy elsewhere. In response, the UK government has indicated that they accept this position and will look to/have extended [HG1] [SW2] forthcoming animal welfare legislation to include lobsters, octopus and crabs and all other decapod crustaceans and cephalopod molluscs. [SW3] 

Commissioned by the UK’s Department of Environment, Food and Rural Affairs, this report by Dr Jonathan Birch and colleagues is essential reading for anyone interested in animal sentience and welfare issues concerning cephalopods and crustaceans. To reach their conclusion, the authors developed a reasoned methodology for assessing evidence of sentience in animals. (They define sentience in the report as the capacity to feel, to experience pain, distress, hunger and thirst and also pleasure, warmth, joy, comfort and excitement).

Their methodology uses eight criteria to evaluate scientific evidence of sentience. These are:

• Possession of nociceptors;

• Possession of integrative brain regions;

• Connections between nociceptors and integrative brain regions;

• Responses affected by potential local anaesthetics or analgesics;

• Motivational trade-offs that show a balancing of threat against opportunity for reward;

• Flexible self-protective behaviours in response to injury and threat;

• Associative learning that goes beyond habituation and sensitisation; and

• Behaviour that shows the animal values local anaesthetics or analgesics when injured.  

These criteria are not just relevant to the cephalopod molluscs (which include octopods, cuttlefish and squid) and decapod crustaceans (which include crabs, lobsters, crayfish, shrimps and prawns) being considered in the report but can be applied more broadly, to any animal, eg to whether social insects such as bees and wasps, which have also been attracting increasing interest, are sentient.

Based on the available evidence, its reliability and quality, Birch et al arrive at one of six confidence levels for each criterion. Where there is a large amount of high quality, reliable evidence, that leaves no room for reasonable doubt, they conclude that they have a ‘very high confidence’ that a criterion is fulfilled/failed. ‘High confidence’ is used when they were convinced that the evidence supports an animal fulfilling/failing the criterion, even though some room for reasonable doubt remains. ‘Very low’ or ‘no confidence’ is used when the evidence is either seriously inadequate or non-existent. Other levels used are ‘medium’ and ‘low’. Birch et al also highlight that having ‘low’ or ‘very low’ confidence is not the same thing as sentience being unlikely or disproved, simply that the evidence one way or another is patchy or of low quality.

The level of confidence in each criterion is then used to form an overall judgement of the likelihood of sentience; high or very high confidence that an animal satisfies seven or more of the criteria is regarded in the report as amounting to very strong evidence of sentience. High or very high confidence that an animal satisfies five or more criteria amounts to strong evidence and high or very high confidence that an animal satisfies three or more criteria amounts to substantial evidence of sentience. Birch et al conclude that, using this metric, there is very strong evidence of sentience in octopods and substantial evidence for other coleoid cephalopods (squid and cuttlefish). Similarly, there is strong evidence of sentience in true crabs (infraorder, Brachyura) and substantial evidence of sentience in anomuran (hermit) crabs and lobsters/crayfish (infraorder, Astacidea).

In view of this, the report calls for protection of all cephalopods and decapods in general legislation, and the development of enforceable best practice guidance and regulations that are specific to the welfare needs of commercially important species.

In the second part of the report, Birch et al detail the welfare implications of their conclusion of sentience and the insults and challenges that cephalopod molluscs and decapod crustaceans experience and implications for current and future commercial practices in the fishing industry. The most concerning is their conclusion that there currently exists no humane way to kill cephalopods, that is commercially viable. They strongly recommend the development of codes of best practice and further research on more humane slaughter methods.

Other concerns highlighted include the practice of declawing (the removal of one or both claws from a crab) and nicking (the cutting of the tendon of a crab’s claw), both of which they have high confidence causes suffering and is a health risk to the animals.

They recommend a ban on the sale of live decapod crustaceans to untrained, non-expert handlers (currently it is possible to order live crabs and lobsters from online retailers) and make recommendations on general storage and transport.

The report also recommends that a range of commonly used slaughter methods are banned in all cases for decapod crustaceans whenever a more humane slaughter method is available, unless electrical stunning has first occurred. These include boiling alive and/or slowly raising the temperature of water that a crab, etc is in. More humane slaughter methods are double-spiking (for crabs), whole-body splitting (for lobsters), and electrocution using specially designed devices.

A further concern is the developing practice of commercially farming octopus, as the authors conclude that it is impossible to achieve good welfare in such systems and suggest the UK government should consider a ban on imported farmed octopus and to prevent the setting up of any such farms in the UK.

Lastly, they lay out areas where knowledge is lacking and where research is needed.

In response to the report, the UK’s Minister for Animal Welfare, Lord Goldsmith, announced that forthcoming legislation has been extended to recognise lobsters, octopus and crabs and all other decapod crustaceans and cephalopod molluscs as sentient beings.

“The UK has always led the way on animal welfare….  The Animal Welfare (Sentience) Bill provides a crucial assurance that animal wellbeing is rightly considered when developing new laws. The science is now clear that crustaceans and molluscs [HG4] [SW5] can feel pain and therefore it is only right they are covered by this vital piece of legislation.”


Review of the Evidence of Sentience in Cephalopod Molluscs and Decapod Crustaceans (November 2021). A4, 107 pages. Report by Jonathan Birch, Charlotte Burn, Alexandra Schnell, Heather Browning and Andrew Crump is available for download: https://www.lse.ac.uk/business/consulting/reports/review-of-the-evidence-of-sentiences-in-cephalopod-molluscs-and-decapod-crustaceans.

S Wickens,

Genome editing and farmed animal breeding: social and ethical issues

The Nuffield Council on Bioethics has published in December 2021 their most recent report on the social and ethical issues associated with the use of genome editing in farm animal breeding. The Nuffield Council on Bioethics is an independent body based in the United Kingdom that examines and advises on ethical issues arising from developments in bioscience and health. The Council is made up of around 15 members and 12 executive staff. It was established by the trustees of the Nuffield Foundation in 1991, is funded jointly by the Nuffield Foundation, the Medical Research Council and Wellcome. One of their terms of reference is to identify and define ethical questions raised by recent developments in biological and medical research that concern, or are likely to concern, the public interest; and the Council reviews the available evidence with a view to report on these matters and to make recommendations relating to policy and practice.

In the report, the Council seeks “to identify and examine ethical questions relating to the impact of genome editing technologies on the production, use and welfare of animals for direct human consumption (or for the production of goods for human consumption)”. The first chapter covers domestication and farmed animal breeding from the Stone Age to the present day, which is no small feat in 20 pages. This is followed by an outline of the five societal challenges to the current food and farming system. These relate to (i) animal health and animal welfare; (ii) human health; (iii) demand and supply; (iv) social, cultural, and political challenges; and (v) environmental and ecosystem challenges. It is acknowledged that “the challenges are interconnected so that interventions to ameliorate some may ameliorate or potentially also aggravate others.” This also leads to the conclusion that that it will not be possible to respond to one challenge without having some effect on the others. In Chapter 3, the Council propose an ethical standard to guide and evaluate interventions in food and farming systems. In terms of animal welfare, the Council express the view that sentient, non-human animals have morally relevant basic interests. They are dependent on food and farming systems for the conditions that enable them to live good lives.

The subsequent chapter tackles the prospective breeding interventions resulting from innovations in breeding technology. Some aspects of potential welfare benefit to the animal are mentioned, such as the introduction of polled (hornless) genes to prevent disbudding, and increased disease resistance. However, this is followed by the warning that it would be unacceptable to adapt animals purely so that they may endure conditions of low welfare without showing the associated adverse health effects. Indeed, in one section the Council asks the reader to imagine the breeding of tailless pigs to eliminate the need for tail docking as a way to explore the limits of the desirable uses of biotechnology. In the next two chapters, the report investigates first the attitudes of consumers and the public to biotechnologies and novel foods, before describing existing legal and regulatory controls governing the adoption of new breeding technologies, mainly from a UK perspective.

Overall, the report is a valuable source of information on a difficult subject, containing more than 800 references, and a very useful glossary section. The Nuffield Council on Bioethics has published a two-page overview which is available along with the full report, and a shorter, 16-page summary outlining the main themes, findings, and recommendations.

Genome Editing and Farmed Animal Breeding: Social and Ethical Issues (December 2021). A4, 223 words. Published by the Nuffield Council on Bioethics and all versions are available for download at: https://www.nuffieldbioethics.org/publications.

Birte L Nielsen,


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