Technical ReportPDF Available

Dolphin Exploitation and Suffering at SeaWorld Parks

  • Foundation to Support Animal Protection (PETA Foundation)
  • Terramar Research and SONAR


Dolphins at SeaWorld are confined to artificial, highly unnatural environments that prevent them from performing even the most basic, biologically driven behavior and routinely expose them to damaging psychological trauma, social stress, and physical injury. Their well-being is compromised when they are exposed to excessive anthropogenic noise and harassment from crowds of park visitors and confined to severely crowded, barren enclosures that offer them no means of physical or visual escape and thwart their natural use of sonar. Housing them in such conditions not only is detrimental to their health and well-being but also sends the harmful message to the public that confining them, repeatedly harassing them, and depriving them of everything natural and important to them is acceptable—a message that can stifle compassion in park visitors and confound good conservation efforts.
In 2016, SeaWorld announced that it would end its orca-breeding program after facing mounting criticism from
scientists and the public over its poor treatment of captive orcas (Howard, 2016). Since this announcement, however,
the company has continued to breed bottlenose and Pacic white-sided dolphins—the orcas smaller cousins—and
house them in small, concrete tanks, as well as exploiting them in archaic, circus-style performances and interactive
programs in which they’re touched, grabbed, and stood on by trainers.
In November 2018, a veterinarian observed the captive dolphins held at the SeaWorld parks in San Diego,
San Antonio, and Orlando. Evidence obtained from those observations revealed that the well-being of captive
dolphins at the parks is severely compromised by the conditions in which they’re forced to live. is includes an
astonishing number of dolphins—140—conned to just seven tanks at four SeaWorld–owned theme parks in the
Unites States.i is report provides a glimpse into the miserable lives of these exploited animals, who endure routine
physical, psychological, and social stress and at times sustain painful injuries as a result.
Heather D. Rally, D.V.M.
Supervising Veterinarian, PETA Foundation
Toni Froho, Ph.D.
Behavioral Biologist and Research Director, TerraMar Research
JUNE 5, 2019
© Brewster
Captive dolphins at SeaWorld are housed in severely crowded, extremely shallow, small enclosures that are spatially,
acoustically, and visually unnatural to the species. Most have barren concrete walls with bright, reective surfaces that
prioritize maximum visibility and accessibility of dolphins for park visitors over consideration of the animals’ health
and welfare. For example, in SeaWorld’s shallow petting pools, members of the public are permitted direct access to
the edge of the pool and are frequently observed harassing the dolphins by splashing and submerging their arms and
hands in an attempt to grab and touch the animals. e tanks are devoid of sucient depth and any natural features,
hiding places, or variability that would allow the dolphins to take refuge from conspecics or the public, creating
an environment of inescapable, routine stress (Froho & Beko, 2018).
Conning captive wild animals to small, barren, crowded enclosures causes them physical harm and trauma and can lead
to illness and premature death. Studies have shown that far-ranging carnivores, such as dolphins, who would routinely
travel long distances in nature, are acutely susceptible to suering when conned to enclosures—like those
at SeaWorld—that are just a minuscule fraction of the size of their natural home range (Clubb & Mason, 2003).
An extremely small tank at SeaWorld Orlando labeled the “Dolphin Nursery” held at least 11 full-grown adult
bottlenose dolphins. is tank, which is shallow in order to maximize visibility of the animals for park visitors, contains
less than one third of the water that an Olympic-sized swimming pool does. Such a space isnt adequate to house a single
adult bottlenose dolphin, let alone nearly a dozen of these deep-diving, far-ranging, socially complex mammals.
Whether caught in the wild or bred in captivity, dolphins are wild animals who are biologically driven and highly
motivated to engage in specic natural behavior that helps them thrive in the ocean. is behavior includes
swimming distances of up to 60 miles per day, diving to depths of nearly 1,500 feet, and maintaining dynamic
relationships within a large social network (Klatsky, Wells, & Sweeney, 2007; Mann, Connor, Tyack, & Whitehead,
2000). Yet dolphins at SeaWorld are conned to constrained and injurious environments that are lacking in natural
variability and features variability, treated with chemicals, and physically restrictive, with depths that are often only
marginally greater than the legally required minimum of 6 feet (USDA, 2017), which is wholly inadequate and less
than the length of their own bodies.
Dolphins at SeaWorld parks are housed in conditions that exacerbate the impact of unnatural and anthropogenic noise
on them. Acoustic stress is a serious welfare concern for captive dolphins, who would use their sophisticated acoustic
systems to communicate, navigate, hunt, and visualize their environment in the wild with astonishing acuity. eir aural
anatomy and physiology is highly complex and exceptionally sensitive to sources of sound and vibration. e dolphin
tanks at SeaWorld parks—with their parallel concrete walls, metal gates and latches, and mechanical ltration plants and
pumps—create an environment that potentiates anthropogenic noise, vibrations, and reverberations from both inside
and outside the tank (Couquiaud, 2005).
Additionally, at SeaWorld, dolphins are typically conned either to petting pools, in which they’re forced to interact with
park visitors, or to performance pools, in which they’re forced to perform for audiences, both of which present unique
noise insults. Park visitors have been observed tapping, knocking, and even banging on underwater-viewing tank glass
at SeaWorld’s dolphin petting pools in an attempt to attract the animals’ attention. Because of the physical properties of
sound propagation in water, such seemingly innocuous behavior can translate into intrusive noise that routinely assaults
the animals’ hearing inside the tanks, creating an acoustic insult that is likely to cause chronic stress. Dolphins in shows
were also routinely exposed to large, raucous crowds and loud, amplied music projected from speakers surrounding
their tanks. ese noise levels in the air would also be expected to aect dolphins, who must spend signicantly more
time with their heads above the water for shows than they would naturally in the wild (Rose & Parsons, 2019).
A growing body of research has found that exposure to excessive or unnatural levels of noise can aect a number
of health and welfare parameters in cetaceans, including immune suppression, increased aggression, and premature
hearing loss (Couquiaud, 2005). Indeed, captive dolphins who are exposed to acoustic insults are known to
demonstrate physiological and behavioral indications of stress, such as an increase in circulating stress hormones
and a refusal to perform or eat. Captive dolphins have even died because of severe acoustic disturbances (Couquiaud,
2005; Monreal-Pawlowsky et al., 2017).
Another factor that is known to have a dramatic eect on captive dolphins’ health and well-being is acute or chronic
social stress. Dolphins are highly social, with an impressive capacity for emotion as well as self- and social-awareness.
eir complex social networks include intimate, sometimes lifelong relationships between individuals and dynamic
aliations among groups ranging over wide areas (Waples & Gales, 2002). Yet dolphins at SeaWorld continue to be
housed in articial social groups. Given the cramped living conditions that they’re chronically kept in, it’s no surprise
that aggression among them appears to be commonplace.
e dolphins used in theatrical performances and human-interaction programs are required to perform tricks for
a food reward of dead sh. During a performance at the San Diego location, two dolphins aggressively chased,
tail-swiped, and bit at each other while trainers encouraged them to pose for a photograph with members of the
public and allowed the park visitors to feed them by hand. is incident not only placed the public in danger but also
exposed the fact that SeaWorld’s practice of baiting captive dolphins to perform tricks for food rewards contributes
to heightened aggression and social tension among them.
Indeed, many of the dolphins at SeaWorld were observed with rake mark injuries and scars, which are parallel,
linear wounds sustained when dolphins are bitten by conspecics while swimming. In the wild, aggressive encounters
between dolphins can dissipate when a subordinate animal retreats from an aggressor, but in captivity, dolphins
can’t escape from aggressive attacks. is, coupled with the fact that captive dolphins often demonstrate unnaturally
heightened levels of aggression in captivity as a result of stress or deprivation, results in excessive raking incidents.
Indeed, at SeaWorld parks, some of the dolphins were observed with extensive rake mark lesions across their entire
bodies, supporting the conclusion that aggression is commonplace among them.
Dolphins’ skin is their immune systems rst line of defense, and the routine compromise of this important defensive
barrier can have serious health implications. Extensive or repeated breaks in the skin not only are painful but also
expose the tissues and blood vessels to environmental pathogens, increasing the risk of localized and even systemic
infection. Furthermore, dolphins, as a highly social species, are particularly vulnerable to the emotional impact of
social alienation and tension, which can result from resource competition, severe crowding, the transfer of animals
between tanks or facilities, and other management decisions that aect the social stability within a captive dolphin
population. Subordination, alienation, and disrupted social group dynamics have been implicated in both illnesses
and deaths of captive dolphins (Waples & Gales, 2002).
Numerous dolphins at SeaWorld parks were observed with dental trauma, some with cases so severe that every one of their
approximately 100 conical teeth were completely missing above the gum line. Dental trauma is commonly observed in
captive wild animals who develop self-injurious abnormal behavior as a result of chronic behavioral deprivation or trauma
(Morgan & Tromborg, 2007). Severe cases are common in captive marine mammals who are particularly prone to tooth
damage associated with aberrant, self-injurious behavior such as gnawing on hard surfaces in their tanks or aggressively
“jaw popping” at conspecics, sometimes through metal separation gates (Rose & Parsons, 2019).
Severe or sudden dental trauma, such as a fracture, can expose
the living pulp cavity within the tooth. Dental trauma of this
nature not only is painful but also predisposes animals to
infection (Holmstrom, 2018). Indeed, it is well documented
that captive orcas, who are well known for having high rates
of dental trauma, routinely develop repeated infections of
traumatized teeth that require regular antibiotic therapy to
prevent local and systemic infection (Cornell, 2011; Jett, Visser,
Ventre, Waltz, & Loch, 2017). In addition to the direct health
risks that dental trauma poses, the routine or inappropriate
use of antibiotics can promote antibacterial resistance, creating
a risk of more severe and potentially untreatable infections in
the future. Notably, numerous systemic diseases that are linked
to dental infections can be life-threatening, and captive
dolphins routinely die prematurely of infectious diseases
in marine parks despite access to around-the-clock veterinary
care (Tryland, Larsen, & Nymo, 2018).
Dolphins conned to show tanks are surrounded by stadiums full of people and required to perform up to twice a day.
ey engage in a variety of circus-style tricks that are devoid of both biological signicance to them and educational value
to the public, including allowing trainers to “surf” on their back or stand on the beak-like part of their mouth called the
rostrum. ese tricks are completely unnatural and send confusing messages to the public about normal dolphin behavior
and safe human-dolphin interactions.
Furthermore, countless dolphins at SeaWorld parks were observed with active wounds on the tip of the rostrum or scars
indicating pre-existing wounds. It is common for captive dolphins to injure their rostrum while conned to a restrictive
environment in which they’re surrounded by unnaturally hard surfaces, such as concrete and metal, that easily cause trauma
to the skin. Despite the obvious vulnerability of the rostrum to injury and the evidence of existing wounds on numerous
dolphins, SeaWorld continues to force these animals to perform demeaning tricks that could cause skin abrasions in that
area—including allowing trainers to stand on their rostrum while propelling them through and out of the water.
e dolphin’s lower jaw, or mandible, supports nearly the full force of the trainer’s bodyweight during tricks that involve
standing on the rostrum. e mandible is a sensitive structure that plays an important role in hearing. It is lled with
delicate fatty tissue that allows dolphins to receive underwater sound vibrations through the jaw bone. ese are then
transmitted directly to the inner ear, where they’re perceived as sound (Rommel, Costidis, & Lowenstine, 2018).
us, the bones and joints of and around the mandible are important to the animals’ acoustic health, and routine
exposure to excessive or abnormal force on these structures could not only be uncomfortable but even cause damage.
Female dolphins at SeaWorld are routinely impregnated either when they’re conned with sexually mature males or
through forcible articial insemination (AI), which often requires sedation with diazepam so that semen can be manually
deposited into the reproductive tract using a catheter (Robeck et al., 2005). SeaWorld even employs articial reproductive
techniques to manipulate the sex ratio of its captive dolphin population and manually select for female calves in the hope
that they will grow into successful breeders. Indeed, out of 30 sex-selected inseminations, 28 have resulted in the births of
females (Robeck, O'Brian, & Atkinson, 2018).
Despite frequent claims by SeaWorld that its AI techniques may one day be used to assist conservation eorts (Robeck
et al., 2004), it’s unlikely that such invasive techniques would ever be attempted or successful with an endangered animal
in the wild. e reasons for this are multifaceted and include behavioral, physiological, and logistical constraints (Rose
& Parsons, 2019). For one thing, successful AI procedures require precise knowledge of the reproductive physiology and
endocrine function of the species. Dierent species of cetaceans have dramatically dierent reproductive physiologies,
making AI techniques that were successfully applied in one species unlikely to succeed in another (Robeck et al., 2018).
Furthermore, such AI procedures are invasive and uncomfortable, if not painful, to animals, who often require sedation
even when fully habituated to human handling. Endangered species of cetaceans are often uniquely, and sometimes fatally,
vulnerable to the stress of handling, making it unsafe to perform AI procedures that require capture, restraint,
and prodding of the reproductive tract (Rojas-Bracho et al., 2019).
us, it is exceedingly clear that SeaWorld’s dolphin-breeding program will never directly support conservation eorts
and does not exist for that purpose. On the contrary, AI is conducted at the park for the sole and obvious purpose of
producing more dolphins to ll the company’s tanks for prot, all while condemning animals to a miserable existence
devoid of all the things that are meaningful to them and necessary for their well-being.
Dolphins at SeaWorld are conned to articial, highly unnatural environments that prevent them from performing
even the most basic, biologically driven behavior and routinely expose them to damaging psychological trauma, social
stress, and physical injury. eir well-being is compromised when they are exposed to excessive anthropogenic noise
and harassment from crowds of park visitors and conned to severely crowded, barren enclosures that oer them no
means of physical or visual escape and thwart their natural use of sonar. Housing them in such conditions not only
is detrimental to their health and well-being but also sends the harmful message to the public that conning them,
repeatedly harassing them, and depriving them of everything natural and important to them is acceptable—a message
that can stie compassion in park visitors and confound good conservation eorts.
ese highly intelligent, socially and emotionally complex, far-ranging carnivores are among the most exploited of all
the captive wild animals in the United States. In 2014, after public sentiment shifted overwhelmingly away from
keeping dolphins in captivity and advancements were made in scientic knowledge regarding their welfare in captivity,
the National Aquarium in Baltimore announced plans to retire its remaining dolphins to a seaside sanctuary, noting,
“Times have changed, and our understanding of the needs of the animals in our care has changed.” SeaWorld should follow
suit, but it must immediately stop abusing dolphins by allowing trainers to ride on their backs and stand on their beaks.
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Mammal Medicine, 3rd Edition (pp. 169-209). New York, New York: CRC Press.
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iInventory includes dolphins at SeaWorld Orlando, SeaWorld San Diego, SeaWorld San Antonio, and Discovery Cove Orlando from Ceta Base: Captive
Cetacean Database. “Cetacean Database: Living Population, All Species.” Accessed 11 February 2019.
... While we may know more about these species than other taxonomic groups, it is still difficult for us to use "The Five Freedoms" to assess welfare (Binding et al., 2020). Fig. 3 shows us how the elongated jawline of a dolphin predisposes the public to believe that it is expressing normal behavior (Rally & Frohoff, 2019). However, we can assume it is in discomfort due to its injury. ...
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DOLPHINS in a captive setting can be occasionally subjected to a variety of potentially stressful situations. The stress response comprises a variety of biological reactions to internal or external stimuli elicited when an individual perceives (real or not) a threat to its homoeostasis (Moberg and Mench 2000). The stress response is a complex interplay of behavioural and physiological strategies to cope with changes in the environment (Tsigos and Chrousos 2002, Sheriff and others 2011). Noise can act as a stressor to dolphins because cetaceans rely heavily on sound for many important life functions. This reliance on sound means it is quite likely that exposure to noise will have some detrimental effects on these life functions (Wright and others 2007). Observed effects of noise on marine mammals include: changes in vocalisations, respiration, swim speed, diving and foraging behaviour; displacement; avoidance; shifts in migration path; stress; hearing damage and strandings, but responses of marine mammals to noise can often be subtle and barely detectable (Weilgart 2007). If there is no obvious change in behaviour, stress is difficult to assess in dolphins, both individually and as a group. In order to detect the presence of stress responses in these situations, the endocrine response to stressors is assessed evaluating the hypothalamic–pituitary–adrenal (HPA) axis activity in dolphins and other cetaceans (Wright and others 2007, Amaral 2010). The HPA axis is a key element of the stress response and, when activated, the resultant hormonal cascade increases the levels of glucocorticoids (GCs) …
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Some species - ring-tailed lemurs and snow leopards, for example - apparently thrive in captivity, whereas others, such as Asian elephants and polar bears, are prone to problems that include poor health, repetitive stereotypic behaviour and breeding difficulties. Here we investigate this previously unexplained variation in captive animals' welfare by focusing on caged carnivores, and show that it stems from constraints imposed on the natural behaviour of susceptible animals, with wide-ranging lifestyles in the wild predicting stereotypy and the extent of infant mortality in captivity. Our findings indicate that the keeping of naturally wide-ranging carnivores should be either fundamentally improved or phased out.
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Research was conducted to define the basic reproductive physiology of killer whales (Orcinus orca) and to use this knowledge to facilitate the development of artificial insemination procedures. The specific objectives were 1) to determine the excretory dynamics of urinary LH and ovarian steroid metabolites during the estrous cycle; 2) to evaluate the effect of an exogenously administered, synthetic progesterone analog on reproductive hormone excretion; 3) to validate the use of transabdominal ultrasound for ovarian evaluation and timing of ovulation; 4) to examine the quality of semen after liquid storage and cryopreservation; and 5) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of 41 follicular phases and 26 complete cycles from five females, estrous cycles were 41 days long and comprised a 17-day follicular phase and a 21-day luteal phase. A consistent temporal relationship was observed between peak estrogen conjugates and the LH surge, the latter of which occurred approximately 0.5 days later. Two animals placed on oral altrenogest (three separate occasions for 30, 17, and 31 days, respectively) excreted peak urinary estrogen concentrations 25 days after withdrawal that were followed by sustained elevations in urinary pregnanediol-3alpha-glucuronide excretion. Mean preovulatory follicle diameter was 3.9 cm (n = 6), and ovulation occurred 38 h (n = 5) after the peak of the LH surge. Based on visual estimates of motility, liquid-stored semen maintained 92% of its raw ejaculate sperm motility index (total progressive motility x kinetic rating [0-5 scale, where 0 = no movement and 5 = rapid progressive movement]) when held at 4 degrees C for 3 days postcollection. Semen cryopreserved using a medium freezing rate demonstrated good postthaw total motility (50%), progressive motility (94%), and kinetic rating (3.5). Insemination during eight estrous cycles resulted in three pregnancies (38%), two from liquid-stored and one from cryopreserved semen. Two calves were delivered after gestation lengths of 552 and 554 days, respectively. These data demonstrate the potential of noninvasive endocrine monitoring combined with serial ultrasonography to improve our understanding of the reproductive biology of cetaceans. This fundamental knowledge was essential for ensuring the first successful conceptions, resulting in live offspring, using artificial insemination in any cetacean species.
The behavior of offshore bottlenose dolphins (Tursiops truncatus) in deep water and near oceanic islands is not well known. Using satellite-linked, time-depth recorders, we investigated the movements and dive behavior of offshore bottlenose dolphins in the deep waters surrounding the Bermuda Pedestal. Three dolphins were tracked from 5 to 45 days and traveled a mean distance of 28.3 km/day where mean water depth was -1,402.0 m ± 1,120.7 SD. Regular dives during the night (2100-0259 h local time) to depths greater than 450 m (8.9% of total dives), 46.4% of night dives lasting longer than 5 min, and high hematocrit values reveal the deep-diving capabilities of offshore bottlenose dolphins. During the day (0900-1459 h local time), dives tended to be shallow, with 96% of dives within 50 m of the surface, and of short durations, with 52.7% lasting less than 1 min. At dusk (1500-2059 h local time), the number of dives increased (X̄ = 72.4 ± 19.6), indicating a diel dive cycle. The dive patterns of bottlenose dolphins in Bermuda waters correlate with the reported nightly vertical migrations of mesopelagic prey along the steep-sided Bermuda Pedestal.
Stress can increase an organism’s susceptibility to disease. Thus, managing stress and its causes are important elements of captive care. Social factors such as changes in group dynamics, competition over resources, and unstable dominance hierarchies are potential stressors for highly social animals such as bottlenose dolphins (Tursiops sp). We present three case studies of mortality and illness in captive bottlenose dolphins and suggest that stress, resulting from social instability and ensuing aggressive interactions, is likely to have played a role in these health consequences. Stress is implicated by blood profiles, loss of appetite, and gastric ulcers, and social problems and instability are evident in the quantitative analysis of individual activity levels and association patterns. This is a unique study on marine mammals in that it demonstrates a correlation between quantitative behavioral indices and physiological measures of stress and health. Recommendations are made for the management of captive dolphins including regular quantitative assessment of behavior and associations and maintenance of appropriate groupings of age and sex classes. Behavioral records can be an important early indicator of health problems and may also serve as a useful tool for recognizing potentially stressful social changes and circumstances. Zoo Biol 21:5–26, 2002. © 2002 Wiley-Liss, Inc.