The Case Against Marine Mammals in Captivity

The Case Against Marine Mammals in Captivity was first produced in 1995 as a comprehensive resource for the public, the media, scientists, students, and policymakers to learn the various arguments against holding marine mammals for public display in zoos, aquaria, and marine theme parks. Marine mammals—a group of animals that are ecologically tied to the ocean environment—cannot thrive in confinement. No concrete tank or small sea pen can provide an animal with anything close to the complexity of coastal habitats or the open sea. Marine mammals, but especially the larger, wide-ranging predators such as whales, dolphins, and polar bears, simply do not belong in captivity.

The 6^th edition of The Case Against Marine Mammals in Captivity is now available. Updates from the 5^th edition include a new chapter on industry research, new information on historic captures of species not currently found in captivity, summaries of various incidents that have occurred since 2019, and 75 new endnotes.

Highlights include:

Chapter 1 – Education

The primary justification for the public display of marine mammals is the educational benefit of these exhibits. However, an objective, detailed evaluation of the educational programs offered by a representative selection of marine theme parks and aquaria has still not been conducted, despite at least 15 years of awareness of this lack.
At a 2010 congressional oversight hearing on zoo and aquarium educational requirements under the Marine Mammal Protection Act (MMPA), a representative of the relevant government agency testified that his agency left oversight of educational programs to the public display industry itself, despite the MMPA’s directive for government authorities to ensure that education provided by the industry meets professional standards. Over 13 years later, this remains unchanged.
In a 2018 international survey, respondents who supported holding cetaceans in captivity were significantly more likely to believe cetacean conservation was not important, which is not consistent with the public display industry’s argument that their facilities educate the public about the urgency of conservation efforts.

Chapter 2 – The Conservation Fallacy

Fewer than 5 to 10 percent of zoos and aquaria are involved in substantial conservation programs. The amount spent on these programs is a mere fraction of the income generated by the facilities. Simply exhibiting wildlife is not considered conservation.
Dolphinaria and aquaria have often presented their marine mammal breeding programs as conservation efforts, but at the same time have claimed that captive-bred and even long-term captive, wild-caught whales and dolphins cannot be released to the wild because they are “domesticated.” These are mutually exclusive positions. Also, very few endangered or threatened marine mammal species are displayed in dolphinaria and even fewer are being successfully bred there. Breeding non-endangered species that will never be released to the wild is not conservation breeding.
A recent interest by conservationists in exploring options for capture and captive breeding of endangered cetaceans ignores a dismal history of attempts in the 1960s and 1970s to capture these species for display. Most such attempts ended in the early deaths of the unfortunate targets.
For the commonly held species today, some long-term captive, wild-caught whales and dolphins have been released to the wild successfully, after careful rehabilitation. Several dolphins, two in Turkey in 2012 and five in South Korea in 2013 and 2015, after several years in captivity, were released in their native waters and tracked over time. They survived, in the latter case for at least several years, with two females successfully reproducing (four of these five dolphins were still alive in 2022). It remains to be seen if captive-bred marine mammals can learn sufficient survival skills to become independent in the wild.
Many captive-bred marine mammals are inbred or hybrids (from different populations and even species). Orcas in particular are often highly inbred, the result of matings between uncles and nieces, sons and mothers, and half-siblings. These products of incest would never be candidates for release; therefore, again, such breeding is not for conservation purposes.
Husbandry practices in most zoos, dolphinaria, and aquaria frequently separate offspring from their mothers long before they would separate from each other in the wild. This has resulted in many captive-bred animals’ lacking essential survival and reproductive skills.

Chapter 3 – Industry Research

A recent surge in captive cetacean research in the last few years has focused on welfare. However, these studies have yet to ask key questions—such as, are captive dolphins more or less active than free-ranging dolphins?—and seek to confirm existing biases rather than question whether captive marine mammal welfare is optimized.

Chapter 4 – Live Captures

While many members of the general public believe it is a thing of the past, live captures of free-ranging marine mammals, particularly whales and dolphins, continue. The capture hotspots in 2023 are Japan (multiple dolphin species) and Cuba (bottlenose dolphins). The principle market today is China, where the number of ocean theme parks has, until recently, rapidly expanded—with the number of operational facilities growing from 39 in 2015 to 96 in early 2023. The Middle East is also importing dolphins for display.
Drive-caught animals of several species are found in Japanese and other Asian dolphinaria, and at least 105 facilities in 20 countries have sourced Taiji dolphins for public display over the years. Although drive-caught animals have not been directly imported into the United States for more than 25 years, these animals are still found at swim-with facilities frequented by American tourists.
A population of orcas in the Pacific Northwest of the United States was declared endangered in 2005 and has shown no recovery as of 2023. This is partly because an entire generation (at least 53 juveniles), many of whom would have contributed offspring to the population over the past decades, is simply missing, removed in the 1960s and 1970s for public display. Only two of these captured whales remain alive in marine theme parks today.

Chapter 5 – The Physical and Social Environment

Field research over the past 15 years has determined that most species of marine mammal, especially whales and dolphins, range more widely over time, travel farther daily, and routinely dive deeper than was previously believed, before the advent of advanced technology (including GPS tracking, dive monitors, underwater cameras, and drones). Yet the standards globally, including in the United States, for captive enclosure size for these oceanic mammals have not been revised or improved in response to this increasing body of science.
Marine mammals are unique when it comes to captive wildlife because of their oceanic habitat. Captive enclosures cannot simulate the complexity of the ocean and coasts. Enclosure sizes are generally less than one-ten thousandth of 1 percent of natural habitat range.
Tanks are barren and lack texture and features that engage the interest of the marine mammals held in them. Sea pens are sometimes better, but often located in areas with high tourist traffic but poor water quality.
Dolphin sea pen enclosures in Asia and the Caribbean are considered to be at extreme risk from hurricanes and tsunamis. Their construction also degrades coastal habitat, destroying mangroves and damaging coral reefs.
Several dolphin facilities in the Wider Caribbean Region have been severely damaged or destroyed by increasingly massive hurricanes (the 2017 season was particularly destructive), the result of climate change.
Dolphinaria in desert environments have proven problematic—a purpose-built facility in Arizona, which began operation in 2016, was closed by 2019 due to the deaths of four of its eight dolphins. The survivors were sent to a sea pen dolphinarium in the US Virgin Islands.
A 2017 review of sea otters in captivity notes that the space provided even this small marine mammal is not typically sufficient for the animals’ needs.
The US Department of Agriculture proposed updating its captive marine mammal regulations in 2016, yet these updates did not include expanding the space requirements for any species. Regardless, as of 2017, the proposal was withdrawn and the US regulations remain almost 40 years out of date.

Chapter 6 – Animal Health Issues and Veterinary Care

Studies examining health records over multiple years have identified several health conditions afflicting marine mammals at higher rates in captivity than in the wild. The public display industry addresses the symptoms of these conditions rather than determining the causes and preventing the conditions from developing in the first instance.
Animal health records and necropsy (animal autopsy) results are treated as proprietary information, rather than valuable scientific data. Access to this information is therefore strictly controlled by the public display industry, rather than made available openly to the research community.
One 2014 study determined that a captive male orca spent almost 70 percent of his time nearly motionless. This is in contrast to studies from 2011, 2012, and 2013 showing free-ranging orcas may travel up to 140 miles a day for up to 30–40 days without rest.
Captive marine mammals often damage their teeth by chewing, or rubbing their teeth on, concrete tank walls and floors and biting down on metal gates. Walruses often have their tusks removed entirely to prevent tusk breakage and orcas routinely grind their teeth down to the gum line from these behaviors.
Recent inspections of two major dolphinaria in the United States have found serious violations of the veterinary standards under US law, leading to the death, injury, or illness of several species of marine mammals, ranging from manatees to orcas. Therefore, despite having years to improve veterinary practices, the public display industry continues to subject captive marine mammals to poor care, even in the “best” facilities.

Chapters 7 and 8 – Behavior and Stress

Captive facilities often provide marine mammals with plastic and rubber “toys” and ropes and claim these enrich their lives. However, these inanimate objects are often ignored, and what little research has been conducted over the years on this topic indicates that such objects fail to engage the animals in any meaningful way.
Increased frequency and intensity of aggressive interactions are often seen in the artificial social groups of captivity.
Orcas are particularly subject to stress in captivity, due to their size and social complexity.

Chapter 9 – Cetacean Intelligence

Cetaceans demonstrate self-awareness and indicate an ability to understand abstract concepts. Their social interactions are complex and they have long memories. A 2012 review concluded “that dolphins have exhibited considerable evidence of high-level cognitive ability and understanding—with higher levels of awareness of self and others than exhibited by human toddlers.”

Chapter 10 – Mortality and Birth Rates

Bottlenose dolphins face a six-fold increase in risk of mortality immediately after capture from the wild and immediately after every transfer between facilities. They (and probably other dolphin species in captivity, including orcas) never become accustomed to transport, and the stress they experience can be fatal.
Survivorship rates have improved for marine mammals, including cetaceans, over the past three decades. However, the lowest mortality rates for captive bottlenose dolphins are seen in the US Navy program. These dolphins live in sea pens and spend time outside those pens in the open ocean (trained to follow boats and return when called), swimming in straight lines and diving deeply.
While survivorship has also improved for orcas, they continue to live shorter lives in captivity than in the wild.
Zoos and aquaria argue that captivity keeps wildlife safe from predators, pollution, parasites, and food shortages, and offers veterinary care. Despite this, no marine mammal species is known to definitively live longer in captivity than in the wild. Public display proponents cannot have it both ways—either captivity is safer and marine mammal life spans should be clearly longer in captivity than in the wild, or something in captivity kills marine mammals with an efficiency at least equal to, and often greater than, that of wild hazards. One obvious culprit in captivity is persistent stress from confinement and artificial social structures.
Marine mammals in captivity have a history of premature deaths from a variety of causes, including drowning, ingesting foreign objects, and attacks from other animals. Several causes, including mosquito-borne illness and skull fractures from jumping out onto concrete decks, are unique to captivity.

Chapter 11 – Human-Dolphin Interactions

Injuries in interactive encounters (whether swim-with-dolphin encounters, feeding sessions, or the like) occur far more frequently than officially reported.
Several tourism companies, including TripAdvisor and Virgin Holidays, have ceased or restricted their promotion of swim-with-dolphin attractions in the past five years, due to concerns about swimmer safety and dolphin welfare.
While a recent study indicated that dolphins in a swim-with-dolphin attraction were not stressed by the activity, the individuals were also allowed to go on open-water “walks” (outside their sea pens), as they are trained to follow boats and return to their trainers when they hear a recall signal. This element of their care, which is rare in dolphinaria, may mitigate any stress they experience due to the swim-with-dolphin activity.

Chapter 12 – Risks to Human Health

The risk of disease transmission or injury to the public or to caretakers from marine mammals is significant. Infection through close contact with people also threatens captive marine mammals. Additional research has led to an expansion of the number of pathogens known to be transmissible between marine mammals and people (in many cases, in both directions).
Captive orcas have killed four people (three trainers and one member of the public) and injured dozens of others. In contrast, there is no record of anyone being killed by free-ranging orcas, despite their fearsome reputation, and the small number of reported injuries (in cases where the orcas apparently mistook people for prey) have been relatively minor. This difference is no doubt due to the unnatural proximity between people and orcas in captivity, but demonstrates why it is unwise to treat these top predators as pets
The California employee safety agency, after investigating an orca attack at SeaWorld San Diego in 2006, predicted a trainer would be killed sooner than later by a captive orca. SeaWorld objected strenuously to this and the agency retracted the statement. Within four years, two trainers were killed by SeaWorld orcas, nine weeks apart.

Chapter 13 – The Blackfish Legacy

Within a year of publishing the 4th edition of this report in 2009, a trainer was killed at SeaWorld Orlando by Tilikum, then SeaWorld’s largest orca, a male who weighed 12,000 lbs. This was not an accident; Tilikum pulled the trainer into the tank, broke her neck, and dismembered her. Only after this occurred did the public learn that another trainer, working with SeaWorld whales on loan to a facility in the Canary Islands (a territory of Spain), was also killed, by a male orca unrelated to Tilikum. Keto, a young male, slammed his trainer against the walls of the tank and crushed his sternum.
SeaWorld was cited by the US Occupational Safety and Health Administration for the death of the Orlando trainer, assigned the highest level of accountability (“willful”), and assessed the maximum fine. SeaWorld sued to overturn this citation; an administrative law judge (ALJ) upheld the citation after a 9-day hearing and SeaWorld’s appeal of this ruling failed. SeaWorld did not take the case to the Supreme Court and the original ruling stands. The ALJ did lower the level of accountability to “serious,” one level below “willful,” but also ruled that “waterwork”—getting in the water with the whales for performances—was unsafe and prohibited it. This prohibition remains.
A book examining these events and the controversy surrounding marine mammal captivity, Death at SeaWorld by David Kirby, was published in July 2012. One year later, a documentary, Blackfish, premiered in theaters. In October 2013, it aired on CNN and was re-broadcast multiple times. It is estimated that, by the end of 2013, over 20 million people had viewed the documentary.
As a result of the impact Blackfish had on the public, several companies ended decades-long partnerships with SeaWorld, sports teams canceled sponsorship agreements, and music acts declined to perform at the SeaWorld parks. Visitorship, stock price, and revenue dropped. This became known as “The Blackfish Effect.”
California passed legislation in 2016 to ban the breeding of captive orcas and their import into the state. At the same time, SeaWorld pledged to end the breeding of captive orcas in all its parks; the orcas it held at that time would be the last generation of whales displayed at SeaWorld. The company also retooled its theatrical shows to be more educational and increased its contributions to conservation initiatives in the wild. As a result of this change in business model, SeaWorld’s stock has finally exceeded its initial public offering price in the past four years. A new SeaWorld facility planned for the Middle East will have no orcas.
The future of captive marine mammals is sanctuary—authentic sanctuaries that offer more natural surroundings and a retirement from performance. Several seaside sanctuary projects are underway.

While in the West, the Blackfish Effect has shifted the debate on captive marine mammals—it is now solidly mainstream—the expansion of the public display industry in the East is still a challenge for those who seek to protect the welfare of captive marine mammals

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