An update on captive cetacean welfare

Introduction

Cetaceans (i.e., dolphins, whales, and porpoises) have long been considered challenging and ethically problematic candidates for captivity (Carter, 1982; Goldblatt, 1993; Lott & Williamson, 2017; Rose et al., 2017; Hosey, Melfi & Ward, 2020; Marino, 2020; Marino et al., 2020; Marino & White, 2022; McGillian, 2023). Typically, only odontocetes (i.e., toothed whales) are held in captivity because mysticetes (i.e., baleen whales) are too large and have feeding habits that make captivity particularly challenging. The 2013 film Blackfish, directed by Gabriela Cowperthwaite, played a key role in changing public sentiment about captive cetaceans, particularly orcas (“killer whales”) by focusing on the disturbing personal history of the orca Tilikum (Parsons & Rose, 2018; Boissat, Thomas-Walters & Veríssimo, 2021). Increasingly, the public in many parts of the world has become more concerned about the welfare of captive cetaceans and less favorable towards captivity itself (Giovos et al., 2019; Naylor & Parsons, 2018). Wassermann, Hind-Ozan & Seaman (2018) found that, when accounting for some biases in previous surveys of visitor attitudes, support for orca shows and swim-with-dolphins (SWD) programs in their survey was well below what had been reported in previous studies conducted on behalf of captive cetacean attraction operators. Clegg (2021) argued that captive cetacean facilities will need to respond to these changing social ethics to survive into the future.

This increase in public concern has led to several legislative efforts around the world to limit or eliminate keeping cetaceans for entertainment. The U.S.-based SWIMS Act (2024), a federal bill to phase out captive cetacean entertainment in the United States, was last reintroduced in 2024. Canadian Bill S-203 (Parliament of Canada, 2025), passed in 2019, bans the breeding and use of captive cetaceans for pure entertainment. In 2021, the French government decreed a trade and breeding ban, which will end whale and dolphin captivity by 2026 (Berry, 2021). In 2024, Belgium officially became the seventh country worldwide and the fourth in Europe to enact a permanent ban on dolphinaria (The Brussels Times, 2024). Most recently, Mexico’s Senate approved a nationwide ban on the use of marine mammals in entertainment (Mexico Daily News, 2025). The above mentioned legislation requires alternative housing options be in place that would improve the animals’ welfare (see ‘Discussion and Conclusion’).

Nevertheless, captive cetacean entertainment persists across 50 countries in the world, with most facilities found in China, the U.S., Mexico (but see above), Japan, and Russia (Ceta-Base, 2025). The scope of the issue of captive cetacean welfare is broad. Globally, more than 3,500 cetaceans are housed in concrete tanks or sea pens/lagoons in ∼350 marine parks, zoos, and military facilities (Ceta-Base, 2025). The most abundant cetacean species in captivity are common bottlenose dolphins (Tursiops truncatus, ∼87% of all cetaceans; Brando et al., 2018), beluga whales (Delphinapterus leucas), and orcas (Orcinus orca), but also includes pilot whales (Globicephala macrorhynchus), Commerson’s dolphins (Cephalorhynchus commersonii), white-sided dolphins (Lagenorhynchus obliquidens), and several other species and hybrids (Ceta-Base, 2025). In North America alone, there are ∼480 bottlenose dolphins, ∼60 belugas, and 18 orcas in captivity (Ceta-Base, 2025).

Animals in zoos and marine parks in the US are covered by regulations set forth under the Animal Welfare Act (2023), which are often under-enforced (Winders & Chilakamarri, 2018). Accrediting organizations (e.g., Association of Zoos and Aquariums, AZA; ∼40 members/facilities housing cetaceans) set welfare standards for their members. More broadly, some professional associations specifically focus on aquatic animals (e.g., Alliance of the Marine Mammal Parks and Aquariums, AMMPA; ∼50 members; European Association for Aquatic Mammals, EAAM). In addition, the World Association of Zoos and Aquariums (WAZA; ∼400 members) provides a platform for collaboration among institutions and sets ethical guidelines but does not serve as an accrediting body. However, even under the highest standards, there remain unique challenges in meeting the essential needs of the animals (Morgan & Tromborg, 2007; Shepherdson & Carlstead, 2020). Moreover, only a relatively small number of facilities (∼2.3%; Catibog-Sinha, 2008; Bacon, 2018) appear to be accredited. For example, China has more than 100 facilities (30 added in just the last five years) holding dolphins (excluding orcas)—the largest number of any country (Ceta-Base, 2025). Only one facility there (i.e., Ocean Park Corporation in Hong Kong) is accredited by the Association of Zoos & Aquariums (AZA) (2025). This indicates the potential for widespread problems in welfare for the majority of captive entertainment facilities.

Recently, a series of nine articles known as the Cetacean Welfare Study examined captive dolphin welfare measurements across 43 accredited zoos and aquariums in seven countries (Lauderdale et al., 2021a; Lauderdale et al., 2021b; Lauderdale et al., 2021c; Lauderdale et al., 2021d; Lauderdale et al., 2021e; Miller et al., 2021a; Miller et al., 2021b; Miller et al., 2021c; Miller et al., 2021d). It was a correlational study designed to identify factors related to the welfare of bottlenose dolphins (Tursiops truncatus), Indo-Pacific bottlenose dolphins (Tursiops aduncus), beluga whales (Delphinapterus leucas), and Pacific white-sided dolphins (Lagenorhynchus obliquidens). This project did not examine unaccredited facilities or those housing other cetacean species. These studies attempted to determine which welfare factors were most important for dolphins, and which ones could be addressed in the future. Identified factors included habitat characteristics and management practices (Lauderdale et al., 2021c; Lauderdale et al., 2021d; Miller et al., 2021b), environmental enrichment (Lauderdale et al., 2021e), health reference intervals (Lauderdale et al., 2021a), biomedical markers (Lauderdale et al., 2021a; Miller et al., 2021d) social behavior (Miller et al., 2021b), and behavioral diversity (Miller et al., 2021a). The findings of these studies are integrated in the present review where relevant.

The science of captive wild animal well-being continues to be informative about the needs of various species held in zoos, marine parks, and aquaria (Whitham & Wielebnowski, 2013; Clegg & Delfour, 2018; Shepherdson & Carlstead, 2020). Yet, several species, including cetaceans, still face significant challenges in captive settings (Clubb & Mason, 2003; Morgan & Tromborg, 2007; Mason, 2010; Fischer & Romero, 2018; Limin et al., 2025). Welfare assessment tools are used to measure how an animal is coping in its environment (Jones et al., 2022). There are numerous markers of poor welfare (e.g., stereotypies, defined as unchanging repetitive actions; Mason, 1991; Jacobs et al., 2021) and, too, ways to determine positive welfare (Lauderdale et al., 2021b). The Cetacean Welfare Study, for example, found that environmental enrichment programs and social management factors were indicative of positive welfare in dolphins in accredited facilities (Lauderdale et al., 2021b). Importantly, good welfare is not simply equivalent to the absence of negative welfare markers (Miller et al., 2020). There are several factors such as diet, shelter, health, ability to express species-specific behaviors, and choice, that contribute to positive well-being (Vicino & Miller, 2015).

The objective of the present review is to examine the current well-being of captive cetaceans. To that end, we review the literature to assess how well the care of captive cetaceans around the world aligns with their needs, aiming to identify remaining challenges. This includes an overview of behavioral and clinical factors in cetacean captivity, particularly in managed settings. Our focus is on the most recent research and representative facilities, many (but not all) of which hold accreditation from one or more professional organizations, presumably indicating higher welfare standards, but we did not exclude unaccredited facilities. Although bottlenose dolphins in accredited facilities are the subject of most welfare assessments and most published literature, it is important to consider other species (e.g., beluga whales, orcas) and to acknowledge that there are also many unaccredited facilities housing cetaceans around the world. Finally, we discuss the ethical implications of our findings.

Literature Review Methodology

Our methodology involved conducting a scoping review of the literature (Munn et al., 2018) on captive cetacean welfare and related topics such as: body condition, dietary preferences, health, stereotypies, disease, maturation, sociality, reproduction, housing, management, enrichment, performance, space, complexity, and behavioral diversity. After a review of that literature, we examined aspects of the captive setting important to cetacean welfare: (a) enclosures, space and exercise, (b) complexity and sensory-perceptual experience, (c) sociality, (d) feeding and cognitive demands, and (e) performances and interactions with humans, as well as specific welfare topics: brain and behavior (e.g., stereotypies, aggression) and physical health (e.g., nutrition and metabolism, skin health, dental disease, digestive and gastrointestinal disease, infections, reproduction, longevity, survival rates, and mortality rates). We examined and included data on free-living and captive cetaceans.

We conducted our primary searches using Google Scholar. We also used our own papers and references from published scientific papers. Given that the field of cetacean welfare advances rapidly, we focused on articles published since 2000 with only a few exceptions. We used 314 substantiated sources of information in this review. These included 246 peer-reviewed papers, 25 chapters in edited books, and seven scientific books. We used 36 sources of gray literature (e.g., conference proceedings, white papers, government documents, accrediting organization websites). We gave priority to the most recently dated findings. Twenty citations were for publications prior to the year 2000, 199 published between 2000–2019, and 95 between 2020–2025. We obtained information about standards and recommended practices published by professional organizations from their websites. Moreover, we did not omit findings that demonstrated improvements in welfare or positive views of captive cetacean welfare because our aim was to generate an accurate, comprehensive and current picture of the status of captive cetaceans. To confirm that our search was comprehensive and inclusive, we examined reference lists of all articles we used. Finally, findings from secondary sources (e.g., review articles, online web pages) were confirmed before being incorporated into the present study.

The Captive Environment

Captivity in the present context is the state of being confined to an artificial environment (usually designed for human benefit/convenience), which is typified by zoos, aquaria, and marine parks but also includes research laboratories and military facilities (Hancocks, 2002; Morgan & Tromborg, 2007; Marino, 2018; Marino & White, 2022). Authentic sanctuaries (discussed in ‘Discussion and Conclusion’ section) are also a form of captivity designed for animals who cannot be released or returned to the wild (Doyle, 2017). They differ in that an authentic sanctuary prioritizes the well-being of each resident over human interests in an entirely non-exploitive setting more consistent with their evolutionary history and needs (Marino et al., 2025). Across these managed establishments, there are significant differences in terms of space allotted, quality of veterinary care, level of visitor interactions, inclusion of demonstrations/performances, and several other factors (Shepherdson & Carlstead, 2020). The captive environment is multifaceted, influencing both physical and behavioral aspects of welfare. Key factors include the size/complexity of enclosures, movement, sensory experiences and mental stimulation, diet, and social interactions.

Current Welfare Issues

The welfare of cetaceans, as with any animal, is multidimensional; each factor involved in their overall well-being is intricately linked to several others. A deep understanding of captive cetacean welfare requires appreciating that many welfare problems, particularly health challenges that present a risk to welfare (e.g., infections, parasites, etc.) occur both in captivity and in the wild. But the critical point is that there are numerous known reasons for illness, injury, and mortality in the wild, including pollution, pathogens, predators, ships, noise, nets, and so on (Bossart et al., 2003; Fair et al., 2017; Avila, Kaschner & Dormann, 2018; Bossart et al., 2019; Sanganyado & Liu, 2022). None of these have any relevance to land based tanks, leaving open the possibility that there are other factors (e.g., stress, novel pathogen and chemical exposure, neurobiological harm) unique to or exacerbated by captivity that contribute to poor welfare and death in captive cetaceans. For example, below we present evidence suggesting that at least some common diseases of captive cetaceans are directly linked to husbandry or environmental conditions. Despite decades of housing cetaceans in captivity and efforts by accredited zoos and aquaria to modify their facilities, husbandry, and preventative medical programs to reduce these diseases, many of them persist.

Although sufficient evidence exists to raise concerns about the health and welfare of captive cetaceans, as is detailed in the present paper, it is important to note that a great deal of data on captive cetacean disease and illness is absent from the literature and is publicly inaccessible. The reason for this is that the medical and behavioral records of these animals are routinely withheld by the institutions housing them, including cause of death data and necropsy reports for deceased captive cetaceans. Despite the value of such records for advancing captive cetacean health, husbandry, and welfare, as well as wildlife conservation efforts, federal agencies with jurisdiction over these animals and facilities have routinely failed to enforce their authority to obtain such records (Rally, Baur & McFeele, 2018). Therefore, it can be expected that the information available and presented herein is likely an under-representation of the true rates and etiologies of morbidity in captive populations.

In this section, we describe the current well-being (mental and physical health) of captive cetaceans, starting with brain and behavioral issues, various dimensions of physical health, and concluding with longevity, survival, and mortality statistics. The chronic stress of coping with the various dimensions of captivity over time has an impact on mental and physical health in cetaceans, as it does in every other species (Marino et al., 2020). All these factors, described more fully below, contribute to a generally problematic picture of captive cetacean welfare.

Environmental Enrichment

Whether zoos and marine parks can, in principle, provide for the needs of cetaceans is a question that has received increasing attention in the domain of environmental enrichment (Brando et al., 2018; Jacobs et al., 2021). The marine park industry was the first to recognize the difficulties cetaceans have in coping with the incongruity between artificial and natural environments (Swaisgood & Shepherdson, 2005; Morgan & Tromborg, 2007). As a result, accrediting agencies require various forms of enrichment, which are implemented to “maximize psychological health” (WAZA, 2025), to stimulate “natural behavior” (Association of Zoos & Aquariums (AZA), 2025), to allow the animal “variety and choices” in their environment (Alliance for Marine Mammal Parks Aquariums (AMMPA), 2025), and to provide the animal with “behavioural choices” and “control over its environment” (EAAM, 2019). The requirement of such ad hoc enrichment constitutes a de facto recognition that the captive environment is inherently impoverished, as has been suggested by several researchers (Hancocks, 2002; Mason & Burn, 2018; Jacobs et al., 2021). This claim has been refuted for accredited dolphin enclosures by Jaakkola (2023), but Jaakkola does not consider facilities housing larger cetaceans or those that are unaccredited. Nevertheless, it should be noted that this refutation is based on an oversimplified interpretation of the impoverishment-enrichment continuum used in laboratory studies whereby Jaakkola isomorphically maps the laboratory paradigm onto captive dolphin enclosures. Simply adding enrichment to an enclosure does not necessarily transition an impoverished environment to an enriched environment (Jacobs et al., 2021).

Traditionally, much of the enrichment for captive cetaceans has involved the presentation of plastic or rubber floating objects (i.e., toys) with which the animals can interact (Brando et al., 2018; Lauderdale et al., 2021e; Jaakkola, 2024). Although such objects may initially arouse interest, habituation occurs relatively quickly (Clark, 2013), which is why variable enrichment schedules and novel items are recommended (Kuczaj et al., 2002). It nevertheless remains unclear to what extent such objects are actually enriching (Delfour & Beyer, 2012). Other types of enrichment may include submerged objects, human interaction/training, as well as food-based, structural, and sensory enrichment (Brando et al., 2018), including classical music (Guérineau et al., 2022). More recent efforts have focused on adding cognitive challenges (e.g., physical or virtual puzzles and games) to the enrichment repertoire (Clark, 2013; Jaakkola, 2024). As summarized by Jaakkola (2024), cognitive stimulation appears to be intrinsically rewarding and has been associated with a variety of positive welfare indicators (e.g., increases in activity, decreased stereotypies, increased exploratory behavior). Yeater et al. (2024) taught dolphins the concept of innovation and found that the activity was intrinsically rewarding and cognitively engaging. Clegg, Borgner-Turner & Eskelinen (2015) found that cognitive foraging enrichment improved welfare by increasing dolphin engagement and motivation in training sessions and led to fewer stereotypic behaviors. Such cognitive challenges need to account for both species and individual differences and need to be at an appropriate level of difficulty to avoid negative welfare outcomes (e.g., unresolved frustration; Jaakkola, 2024). Unfortunately, enrichment activities that are time-consuming tend to be implemented less frequently (Hoy, Murray & Tribe, 2010). Moreover, as of 2017, cognitive enrichment appeared to be the least-used type of enrichment in captive settings (Clark, 2017). However, cognitive-focused enrichment practices have grown in recent years and appear to be more effective in diminishing abnormal stress-related behaviors, at least for smaller cetaceans (Perlado-Campos, 2017; Matrai et al., 2020).

Neuroscience research suggests that a more natural environment is better for the brain and for the emotional health of the animal than are artificially enriched environments (Bennett, Diamond & Rosenzweig, 1972; Lambert et al., 2015; Lambert et al., 2016). Consistent with this notion are studies that suggest that dolphins in captive environments with more natural elements (e.g., sea pens or netted off areas continuous with the ocean) are less stressed and display fewer behavioral abnormalities than those living in tanks. For instance, Ugaz, Sánchez & Galindo (2009) found that the same group of bottlenose dolphins engaged in more active swimming and less logging in open sea pens (with access to ocean and a more complex environment) than when they were in closed facilities with no ocean access. As noted previously, dolphins in closed artificial environments were also found to have higher salivary cortisol levels than those in open sea pens (Ugaz et al., 2013). Moreover, dolphins transferred from concrete tanks to captive ocean environments spent less time in social interactions (Ruiz, Sánchez & Maldonado, 2009). The authors suggested this finding could be due to the significant increase in space available (the ocean habitat was approximately five times the size of the tanks) as well as the opportunity to explore other features of the natural environment, such as fish and other organisms who may be present (Ruiz, Sánchez & Maldonado, 2009).

The above studies, while far from conclusive, strongly suggest that there are welfare benefits to dolphins (and likely other cetaceans) of living in a more natural ocean environment—even when captive. The current literature on environmental enrichment and welfare in cetaceans indicates that much more research is needed to determine the extent to which specific enrichment efforts can improve welfare, with the caveat that certain aspects of enrichment (e.g., space) often cannot reasonably be addressed in traditional captive facilities. The effects of environmental enrichment can only be fully understood by employing well-confirmed welfare tests (Brereton & Rose, 2023).

Discussion and Conclusion

In the present review, to summarize, we discussed some of the most relevant and substantive aspects of captive environments for cetaceans. These include the amount of space provided but also the complexity of the environment. Recent studies suggest that the complexity of a captive environment, and not just the size, is important. The nature of sensory-perceptual experience in captivity is also important for welfare and, as cetaceans are highly acoustically sensitive animals, more research is needed to understand how tank size and shape affects them in terms of acoustic behavior. Other relevant factors are sociality and how groupings in captivity do or do not resemble natural social groups and the longstanding effects on welfare. Finally, feeding, cognitive demands, and interactions with humans are discussed in terms of whether food is not only balanced and nutritional but also is presented in a stimulating way. We then described the mental and physical health of captive cetaceans, starting with brain and behavioral issues, various dimensions of physical health, and concluding with longevity, survival, and mortality statistics. Captive cetaceans, and especially orcas, exhibit several abnormal behaviors in captivity, including oral stereotypies, self harm, and hyper-aggression towards tankmates and humans. In terms of physical health, captive cetaceans suffer from all of the systemic, skin, and digestive diseases known to occur in cetaceans in the wild. This finding begs the question of why they are exhibiting these diseases in a clean, controlled environment. Moreover, reproduction and births remain problematic in captivity. Finally, with the exception of the bottlenose dolphin, no other cetacean species lives as long in captivity as in the wild.

For cetaceans, there appears to be a significant mismatch between the captive and natural environments in the amount and complexity of space available, socio-cultural opportunities, and cognitive stimulation between the captive and natural environments, which contributes to their difficulties in coping with life in concrete tanks (Mason, 2010; Hosey, Melfi & Ward, 2020). Additionally, the natural characteristics of cetaceans (e.g., their need for space, cognitive and social complexity) predict the welfare challenges outlined above (Clubb & Mason, 2007; Pomerantz, Meiri & Terkel, 2013; Hosey, Melfi & Ward, 2020; Mellor et al., 2021). These outcomes are in keeping with Mason’s (2010) study of how different species respond to captivity. Mason (2010) concluded, in fact, that bottlenose dolphins and finless porpoises fare better in captivity than orcas, Fraser’s dolphins, or Dall’s porpoises. Much of the literature we have cited acknowledges areas where further study is needed. For instance, important questions remain about how the amount of space and complexity interact as factors in well-being, how to provide more supportive environments for nursing and rearing calves, and which enrichment methods are long-lasting and the most effective, and why. In addition, it is important to remember that the bulk of the cetacean welfare literature reviewed in the present manuscript, including the Cetacean Welfare Study, focuses on smaller cetaceans in accredited zoos/aquariums. There is much less welfare research on the larger odontocetes like orcas and beluga whales and virtually no research on unaccredited facilities. As such, one has to be careful in extrapolating current welfare findings to all cetaceans across different captive facilities, especially those that are unaccredited.

As noted in the introduction, there is a rapidly growing, largely unaccredited marine park industry in China. This situation has been summarized by Barefoot (2023, p. 284):

Whilst the practice of keeping marine mammals in aquaria is beginning to shift and decline in the west, it is at the same time growing in Asia, particularly China, which is experiencing an increase in captive facilities and trade in marine mammals. China’s number of aquatic theme parks grew from 39 in 2015 to over 80 in operation in 2019 with an additional 25 under construction. As of December 2020, China had over 1,000 cetaceans in captivity. Representatives from both the Chinese government and Chinese aquaria industry have expressed concerns with the rapid development of the industry and reliance on import of wild-caught animals, acknowledging that regulation has not maintained an appropriate pace.

More updated and much more detailed information can be found in a recent report (China Cetacean Alliance, 2024). Although this is not a peer-reviewed source, it provides valuable information about the current state of the Chinese marine park industry. The report notes that, as of July 2024, 101 ocean theme parks were operating in China, with 11 more under construction. Approximately 95 of these facilities offer cetacean shows involving tricks and trained behavior as well as close contact experiences for park visitors. The average size of the performance/exhibit tanks is 15.3 m length, 7.6 m wide, and 6.1 m depth. Over 1,300 cetaceans are currently in captivity in China (up from 184 in 2009; Zhang et al., 2012), including bottlenose dolphins (n = 738), beluga whales (n = 240), and orcas (n = 22). Since 2001, 1,166 cetaceans have been imported. A total of 83 births have been reported since 2002. It has been estimated that only ∼14 of these parks provide any kind of enrichment for the cetaceans. Many of the issues in the report mirror the welfare concerns discussed in the present review (e.g., death of newborn/young calves, conspecific aggression, stereotypic behavior, logging, repetitive regurgitation, and several medical issues—gastrointestinal problems, fungal skin infections, worn down teeth). Thus, globally, significant welfare concerns remain for captive cetaceans. Even in the best, accredited facilities, there are significant (practical) limits to the extent to which land-based entertainment parks can provide larger, more complex, and variable environments that would allow cetaceans to engage in a greater range of natural behaviors. Pierce & Bekoff (2018) point out that discussions of animal welfare in zoos and marine parks often center on incremental improvements while overlooking the fundamental issue of captivity itself, namely the underlying incompatibility between captivity and life in the wild.

Welfare measures and assessments in accredited facilities comprise the bulk of the literature on captive animal welfare because one can collect scientific, quantifiable data. Such studies, however, do not address an important factor: quality of life. Presumably, this is because quality of life is a subjective evaluation made by the non-human animal and is not something one can scientifically measure in the absence of self-reporting. One can conduct choice and preference testing to help determine what is important to an animal (Dawkins, 2003), but the choices provided may not discern what the animal truly prefers, that is, what is actually optimal for the animal. For example, a researcher may give an animal a choice between food A and food Z, but what the animal prefers might actually be food B at time F, and food J at time Y. The former option provides the animal with a choice; the latter option is more reflective of true autonomy. In the Cetacean Welfare Study, “quality of life” is mentioned only one time: “There is a strong commitment among zoos and aquariums to continuously advance an understanding of welfare across facilities using scientific methods to positively impact the quality of life for the animal” (p. 2, Lauderdale et al., 2021b). As such, there is an assumption or belief that improved welfare measures will lead to a better quality of life (Pierce & Bekoff, 2018). However, the Cetacean Welfare Study did not evaluate the actual well-being of the dolphins; in fact, of the nine articles, there is only one mention of the term “well-being” (Miller et al., 2021c), and then only in a quote from Shepherdson (1998). The question thus remains: how can one definitively determine which welfare assessments actually provide quality of life? For example, researchers would probably agree that having autonomy (i.e., choice and control over the environment) should improve well-being (Jaakkola, 2023) by providing captive animals with the opportunity to thrive (Vicino & Miller, 2015; Miller et al., 2020). But the relationship between autonomy and quality of life in a captive setting is not something one can easily quantify.

Although discussions of quality of life may verge into a philosophical realm, it remains a very real and tangible issue for those animals in captivity, and an important consideration when making decisions about animal welfare (Wolfensohn et al., 2015). An emphasis on quality of life leads to a focus on the positive mental experiences of individual animals (Green & Mellor, 2011). There are welfare measures now that attempt to consider quality of life. Here, we briefly highlight only two of them for illustrative purposes. Based on the Five Domains of animal welfare, the Animal Welfare Assessment Grid (AWAG) assesses physical health, veterinary and management issues, environmental comfort, and psychological well-being (Wolfensohn et al., 2015). Although originally developed for assessments in primates, AWAG is adaptable for any species (Wolfensohn et al., 2015). Specific to cetaceans, the Cetacean Welfare Assessment process (C-Well; Clegg, Borgner-Turner & Eskelinen, 2015) for captive bottlenose dolphins includes eleven criteria and a comprehensive collection of 36 species-specific measures. Like many such tools, these are works in progress. Nevertheless, they provide a foundation for more comprehensive assessment programs. A crucial consideration, however, is the extent to which such welfare measures are actually implemented. For the Cetacean Welfare Study, for example, apart from providing baseline reference measures through an iOS application (e.g., blood variables, fecal hormone metabolites; Lauderdale et al., 2021b), it remains unclear if, to what extent, how, or where the welfare measures will be incorporated by captive facilities, and whether corrective action will be taken when deficiencies are identified. In recent years, there have been attempts to apply comprehensive assessment programs for dolphins (e.g., the C-Well, Clegg, Borgner-Turner & Eskelinen, 2015; Dolphin-WET, Baumgartner et al., 2024). These efforts reflect growing progress toward embedding welfare assessments into the daily care of captive cetaceans (Jones et al., 2022).

From an ethical standpoint, the deeper question remains whether cetaceans can truly thrive in captivity, rather than merely survive. Thriving goes beyond physical health or lifespan—it encompasses overall quality of life and well-being. Partoon et al. (2025) suggest that a positive mental state is crucial to an animal thriving, and this involves promoting positive experiences for the animal through a species appropriate diet, naturally occurring social groupings, preventative healthcare, and a species appropriate habitat. Current evidence indicates that, although marine parks and aquariums can upgrade enclosures to offer some physical and behavioral benefit, they remain limited by available space and the artificial conditions required to keep cetaceans—especially larger species—in captivity. With few exceptions (i.e., when individuals are captured from the wild or rescued and held in captivity for a short while), captive cetaceans cannot be released into the wild because they lack basic survival skills. Therefore, there are limited ethical alternatives. One of the most feasible options is a sanctuary, that is, ocean-based captive enclosures where cetaceans can continue to receive human care while experiencing more space, autonomy, and choice in a natural environment. There are currently three cetacean sanctuaries being created by the Whale Sanctuary Project, the National Aquarium, and SEALIFE TRUST (Marino et al., 2025). Authentic sanctuaries, as opposed to greenwashed or temporary sea pen facilities (Speiran, 2025), are still captive environments and therefore will share many management challenges with other captive facilities (e.g., feeding, veterinary care, funding; Bruck, 2024). In particular, a cetacean born into captivity in a tank would likely experience a more challenging transition to an ocean sanctuary than one with experience in the wild or an ocean sea pen (Bruck, 2024). As in other aspects of welfare, it is necessary to be cognizant of individual differences among animals (Hill & Broom, 2009; Marchant-Forde, 2015). Nevertheless, a sanctuary has different tools to mitigate the challenges of captivity such as a larger, more natural environment that offers greater complexity and enhanced sensory-perceptual experiences. As opposed to zoos, marine parks, and other entertainment venues (as well as military and scientific settings) authentic sanctuaries are not driven by objectives that often compete with animal well-being and autonomy (e.g., visitor experiences, scientific studies, breeding through AI). Accreditation standards for cetacean sanctuaries have been adopted by the Global Federation of Animal Sanctuaries (GFAS, 2025; Marino et al., 2025). Authentic sanctuaries for other wild animals, such as elephants and great apes, face many of the same challenges as cetacean sanctuaries but report improved physical and psychological health in their residents after they acclimate to their new environment (Buckley, 2009; Derby, 2009; Grow, 2020).

Although concerns about sanctuaries have been expressed by those who currently work with captive cetaceans (Bruck, 2024; Almunia & Canchal, 2025), it remains one of the only options available for those animals currently held in managed land-based tanks. Clearly, transitioning cetaceans to an authentic sanctuary requires careful planning (e.g., priming the microbiota to buffer against novel pathogens; Dallas & Warne, 2023) and will require continued research to evaluate the welfare of transferred animals. Welfare assessments in sanctuaries will, in some ways, differ from those in zoos and aquariums as the animals will have access to and interact with more natural environments. The goal would be for animals to exhibit (1) greatly reduced or an absence of stereotypies, (2) greater engagement in natural behaviors, including those that were previously unavailable to them (e.g., exploring/interacting with natural features of the environment, foraging), (3) increased time spent in play and other positive behaviors illustrating greater behavioral diversity, (4) time budgets closer to what exists in nature, (5) decreased time spent in human-animal interactions, (6) increased autonomy and the ability to make meaningful choices, and (7) a decrease in physiological indicators of stress. These goals are consistent with the five domains model of animal welfare (Hampton et al., 2023; Partoon et al., 2025). Although none of these, in isolation, indicates that an animal is thriving, the broad confluence of all these factors would indicate more natural behavior and would help attain the goals set by accrediting agencies mentioned previously, namely: “maximize psychological health” (WAZA, 2025), stimulate “natural behavior” (Association of Zoos & Aquariums (AZA), 2025), allow the animal “variety and choices” in their environment (Alliance for Marine Mammal Parks Aquariums (AMMPA), 2025), and to provide the animal with “behavioural choices” and “control over its environment” (EAAM, 2019).

In conclusion, the evidence clearly shows that ongoing health and welfare challenges remain for captive cetaceans, indicating that they are generally unsuited for captivity from both practical and ethical standpoints. Marine parks, particularly those that are accredited and have environmental enrichment programs, have improved in their ability to provide better welfare for captive cetaceans, especially the smaller ones like bottlenose dolphins. Nevertheless, they still cannot fully meet the complex needs of these animals. As interest and experience in captive animal well-being grows, it is essential to acknowledge when certain environments fail to provide what a species needs to thrive. Moving forward, science-based policies should be considered to determine which species should no longer be housed or bred in zoos, aquariums, and entertainment parks.