When asked to picture a zoo, many are reminded of distant summer days spent exploring prestigious zoo institutions with their families. Zoos justify their existence through scientific research, nature conservation, public education, and entertainment. These basic arguments, however, can also be used against zoos – exposing the industry for negligence and driving animals into aberrant behavior.
There are over 10,000 private and public zoos, as well as 200 aquariums worldwide, holding about a million vertebrate animals and hundreds of thousands of fish. The term ‘zoo’ simply means a collection of animals, meaning the term is applicable to large public organizations as well as the smaller collections of animals situated in towns, private backyards, or by roadsides. Each state in the U.S. has its own laws relating to exhibiting animals. Some states have the simple requirement of permission from the Selectman of the town, while others require a zoo license. To obtain a zoo license, one must complete the zoo license application, which does not consist of more than a name, address, and institution information, making it significantly easy for potential zoo owners to acquire the license. The guidelines for housing animals of different species in zoos are even more minimal in other countries. In the ‘Guidelines on minimum dimension of enclosures for housing animals of different species in Zoos’ issued by Central Zoo Authority of India, the prescribed size of the feeding and retiring cubicle for mammalian species of captive animals is unreasonably small. Among the various different wild animals that are advised to be kept in uncomfortably small enclosures are tigers, which can grow up to 3.9 meters but are instructed to be kept in enclosures with the dimensions of 2.75 meters by 3 meters. In Australia, according to the ‘Australian Animal Welfare Standards and Guidelines’, koalas are able to be kept in enclosures with a minimum internal height of 1200 millimeters, or 3.93 feet. Considering koalas typically grow to be 2.8 feet tall, the enclosures are extremely small and unnatural. The lack of experience required to exhibit animals coupled with the unfair dimensions of the enclosures have made zoos more like pitiful prisons and less like ‘collections’ of animals. 
Zoothanasia, the cruel practice of killing healthy zoo animals is a reality for captive animals all over the world. This practice was first brought to the media’s attention in 2014 when ‘Marius’, a healthy 2-year-old giraffe was put down, dismembered, and fed to the lions in front of an audience at a Danish Zoo. Bengt Holst, scientific director at Copenhagen Zoo attempted to justify this inhumane act by stating, “Our giraffes are part of an international breeding program, which has a purpose of ensuring a sound and healthy population of giraffes” assuring there was no place for Marius in the giraffe heard. This instance provoked researchers all over the world to uncover the number of animals routinely killed because they are no longer useful to the zoos. Though EAZA, the European Association of Zoos and Aquaria, does not publish records on the number of animals that have been culled, executive director Dr. Lesley Dickie told BBC he estimated between 3,000 and 5,000 animals were “management-euthanized” in European zoos in any given year. Zoos are instructed to be as transparent as possible when recording data on deaths, but they are fallible and in some instances, information is missing. Zoos legitimize the killing of healthy animals by misusing words such as “surplus” or “euthanization”. Any definition of surplus indicates something along the lines of an amount that is “greater than needed”. In the case of zoos, the term “surplus” boils down to animals who can no longer be used for breeding or for show, and therefore cannot make money for the business. Zoo administrators try their hardest to sanitize the murder of animals by calling it “management-euthanization”. Euthanization is the act of putting to death painlessly by withholding medical measures from a person or animal suffering from an incurable or painful disease/condition. This term is deceiving in the context of zoo administration, considering the animals that are being killed are completely healthy. The animals that are not murdered, are deprived of their natural habitat, forced to live in close proximity with other species, and suffer from depression, boredom, and health risks.
Zoos claim to benefit wildlife conservation, which is the practice of protecting wild species and their habitats in order to prevent species from going extinct. However, even in what is considered to be the best circumstances, zoos are unable to replicate natural habitats, preventing animals from participating in natural activities – roaming, flying, climbing, hunting, and choosing a mate. Zoos also claim they protect species from going extinct, a noble goal which is proved to be false in a study published in the journal PLOS ONE, showing that of nearly 4,000 species in captivity, only 691 have the status of “endangered”. While in some cases confining animals to zoos will keep them alive, it does nothing to protect wild populations or their habitats. In fact, it is nearly impossible for captive-bred animals to be released into the wild due to their inability to acquire the survival skills necessary to live in the wild. According to a team of researchers from the University of Exeter in the United Kingdom, the odds of animals such as tigers and wolves surviving freedom are only 33% percent.  This 2008 study also showed that captive-born carnivores are more susceptible to viruses and diseases, as well as more likely to starve to death than their wild-bred counterparts. A 2015 study published in the Journal of Applied Ecology concluded that captive breeding should be treated as a last resort when species face imminent extinction because, without conservation in the wild, there is no point in captive breeding. 
The Association of Zoos and Aquariums argues that AZA-accredited zoos and aquariums, “play a vital role in educating over 180 million visitors, including 51 million students, each year, about wild animals, their habitats, their related conservation issues, and the ways in which they can contribute to their preservation.” However, “A Global Evaluation of Biodiversity Literacy in Zoo and Aquarium Visitors“, a study from the University of Warwick, found that there was an increase from pre-visit (69.8%) to post-visit (75.1%) in respondents demonstrating some positive evidence of biodiversity understanding. The percent, only slightly more than 5%, is extremely small in terms of the 6,000 visitor sample. PETA also emphasizes the fact that most visitors treat the exhibits as wallpaper, spending only a few minutes at each display, seeking entertainment rather than enlightenment. 
Animals that are put in shows are often abused for the sake of human entertainment. After the release of the film, Blackfish, the dark side of orca shows at Seaworld was exposed. Former trainer, John Hargrove reveals to CBS News, “[Orcas] are being subjected to sunlight, without shade protection – that causes cataracts and damage to the eyes. They’re swimming in chemically-treated water,” and. “You see them grinding down their teeth on the pool walls and ledges, breaking off their teeth where we have to go in and manually drill the tooth.” Since the capture of wild whales has been banned for decades, Seaworld developed an artificial insemination program, in which they breed whales at unnaturally young ages, and too frequently according to Hargrove. As of 2019, it has been recorded that at least 166 orcas have died in captivity, not including 30 miscarried or stillborn calves. Of the 166, 20 orcas belong to Seaworld, where at least 49 have died. Additionally, up to 90 percent of the 11 million tropical fish that enter the U.S. each year are caught illegally using cyanide according to the National Oceanic and Atmospheric Administration. Based on a scientific study on the effects of cyanide exposure, fish suffer “severe gasping, followed by loss of balance and a complete loss of all respiratory activity” upon being squired with cyanide. Cyanide can also cause coral bleaching, alter the coral’s biology, or outright kill it.
The cruel and unnecessary murders of captivated animals need to end. Shows like “Tiger King” emphasize the need for stricter regulations on potential animal owners, while networks such as National Geographic highlight the lives of wild-bred animals who live a life of freedom in their natural habitat. Zoos are a relic of past cruel attitudes of wildlife and should be treated as a last resort for animals who endure barbaric living conditions and suffer painful deaths at the hands of zoo administrators.