Captive Cetaceans Research Articles

Recent Studies on Captive Cetaceans in Japan: Working in Tandem with Studies on Cetaceans in the Wild

Recent technological advances have allowed researchers to acquire a vast amount of information on wild cetaceans, much of which had previously been inaccessible. However, despite these new technologies, existing studies on cetaceans in captivity remain valuable. In this article, we review the recent research conducted on captive cetaceans in Japan to show their importance. We indexed the existing studies regarding behavior (resting behavior, vocal development, social behavior, and behavior differences between species), comparative cognition (echolocation ability), stress reduction,and reproductive physiology. The resulting data, as well as an understanding of the techniques used to obtain these data, will help improve the condition of cetaceans (especially endangered species) kept in captivity and fill in the gaps of studies done on cetaceans in the wild.

Journal Publication Trends Regarding Cetaceans Found in Both Wild and Captive Environments: What do we Study and Where do we Publish?

Scientists conducting research on cetaceans have a variety of publication outlets. However, a formal assessment of those options has not been conducted. To better understand the trends in publications regarding dolphins and whales, we surveyed peer-reviewed articles from 9 different databases. Our survey produced 1,628 unique articles involving 16 cetaceans found both in the wild and in captivity. Each article was coded a variety of information: habitat, geographic location, genus, topic, research design, and journal type. The analyses indicated that 68% studies were conducted with wild populations and 29% were performed with captive populations. A quarter of the journals publishing research on dolphins or whales published almost 80% of all the articles selected for this study. Studies were conducted across many different geographic locations and topics. Other major findings elucidated relationships between various variables. As expected, specific topics were more likely associated with certain research designs, habitats, and journal types. One of the most important findings of this study is the limited publication of research conducted with captive cetaceans. While it is important to continue to examine animals in their natural environments, there is much to be learned from studies conducted with animals in captivity. As a group, we must become cognizant of the publication trends which currently describe our research progress as we integrate our knowledge from captivity and the wild.

Play in Wild and Captive Cetaceans

Although play behavior is difficult to define, it has been abundantly documented in the cetaceanliterature. Play behavior is prevalent among the various taxa and is exhibited by individuals of all ageclasses. However, it is often difficult to follow individuals, observe underwater behavior, and obtainmultiple sightings of individuals when investigating free-ranging populations. Captive studies allowfor the systematic manipulation of variables and the collection of detailed data with regard toindividuals, age, and gender by being able to observe behavior both at the surface and underwater.Pooling information from both wild and captive studies of play allows for more robust theories,conclusions and understanding. In this paper, we provide a review of play behavior in both wild andcaptive cetacean populations as a first step toward a more complete understanding of the significanceof cetacean play.

Bartonellaspecies detection in captive, stranded and free-ranging cetaceans

We present prevalence of Bartonella spp. for multiple cohorts of wild and captive cetaceans. One hundred and six cetaceans including 86 bottlenose dolphins (71 free-ranging, 14 captive in a facility with a dolphin experiencing debility of unknown origin, 1 stranded), 11 striped dolphins, 4 harbor porpoises, 3 Risso's dolphins, 1 dwarf sperm whale and 1 pygmy sperm whale (all stranded) were sampled. Whole blood (n = 95 live animals) and tissues (n = 15 freshly dead animals) were screened by PCR (n = 106 animals), PCR of enrichment cultures (n = 50 animals), and subcultures (n = 50 animals). Bartonella spp. were detected from 17 cetaceans, including 12 by direct extraction PCR of blood or tissues, 6 by PCR of enrichment cultures, and 4 by subculture isolation. Bartonella spp. were more commonly detected from the captive (6/14, 43%) than from free-ranging (2/71, 2.8%) bottlenose dolphins, and were commonly detected from the stranded animals (9/21, 43%; 3/11 striped dolphins, 3/4 harbor porpoises, 2/3 Risso's dolphins, 1/1 pygmy sperm whale, 0/1 dwarf sperm whale, 0/1 bottlenose dolphin). Sequencing identified a Bartonella spp. most similar to B. henselae San Antonio 2 in eight cases (4 bottlenose dolphins, 2 striped dolphins, 2 harbor porpoises), B. henselae Houston 1 in three cases (2 Risso's dolphins, 1 harbor porpoise), and untyped in six cases (4 bottlenose dolphins, 1 striped dolphin, 1 pygmy sperm whale). Although disease causation has not been established, Bartonella species were detected more commonly from cetaceans that were overtly debilitated or were cohabiting in captivity with a debilitated animal than from free-ranging animals. The detection of Bartonella spp. from cetaceans may be of pathophysiological concern.

Examination of blood coagulation time in captive cetaceans and pinnipeds

Examination of blood coagulation time in captive cetaceans and pinnipeds

Aspiration Pneumonia as a Cause of Neonatal Death in Three Captive Bottlenose Dolphins (Tursiops truncates)

Neonatal weakness of calves is one of the common reproductive-related problems in captive cetaceans; clinical signs can be observed in the first few hours after delivery. Three 3-day-old bottlenose dolphins died with history of weakness since birth. Pathological study demonstrated purulent bronchopneumonia associated with prominent bacterial colonies and foreign substances in alveoli, suggesting aspiration pneumonia as a cause of neonatal weakness and resultant death of the three calves.

The Global Trade in Live Cetaceans: Implications for Conservation

Cetaceans—small whales, dolphins and porpoises—have long been popular performers in oceanaria. Captive cetaceans have also been used for research and employed in military operations. In some jurisdictions cetacean display facilities have been phased out or prohibited, and in the US and Hong Kong a high proportion of the whales and dolphins now in captivity have been captive-bred. A large, growing and increasingly opportunistic trade in dolphins and small toothed whales nevertheless exists, its centres of supply having shifted away from North America, Japan, and Iceland to the Russian Federation and developing nations in Latin America, the Caribbean, West Africa, and Southeast Asia. Demand for live captures is being driven by: a new wave of traditional-type oceanaria and dolphin display facilities, as well as travelling shows, in the Middle East, Asia, Latin America, and the Caribbean; increasingly popular programs that offer physical contact with cetaceans, including the opportunity to feed, pet, and swim with them; and the proliferation of facilities that offer ‘dolphin assisted therapy’ to treat human illness or disability. Rigorous assessment of source populations is often lacking, and in some instances live capture is adding to the pressure on stocks already at risk from hunting, fishery bycatch, habitat degradation, and other factors. All too often, entrepreneurs appear to be taking advantage of lax (or non-existent) regulations in small island states or less developed or politically unstable countries to supply the growing global demand for dolphins and small whales. The regulation of trade in live cetaceans under CITES is fraught with problems, not least the poor quality of reporting and the lack of a rigorous mechanism for preparation, review, and evaluation of non-detriment findings. Preparation of this article was supported by WDCS, the Whale and Dolphin Conservation Society. The authors are especially grateful to Cathy Williamson and Philippa Brakes for contributing data, ideas, and helpful critical comments.

Diel patterns in underwater sounds produced by beluga whales and Pacific white‐sided dolphins at John G. Shedd Aquarium

Diel patterns in underwater sounds from five beluga whales (Delphinapterus leucas) and five Pacific white‐sided dolphins (Lagenorhynchus obliquidens) housed at John G. Shedd Aquarium in Chicago, IL were studied. Underwater sounds were sampled systematically over 24‐h periods by using a battery‐operated cassette recorder and an Ithaco 605C hydrophone controlled by a digital timer, which activated every hour and then shut off after 2.5 min. Belugas had 14 sounds and Pacific white‐sided dolphins produced 5 sounds. For each species, the use of some sounds was correlated with other sounds. The diel pattern for both species was similar and mostly affected by the presence of humans. Sounds gradually increased after the staff and visitors arrived, peaked during the midday, gradually decreased as closing of the aquarium approached, and was minimal overnight. These data can help identify the best time of day to make recordings and perhaps could be used to examine social, reproductive, or health changes in these captive cetaceans.

Evaluation of baseline indices of sensibility in captive cetaceans

Twelve possible tests of sensibility and six possible tests of vitality were evaluated for their ease of application and the reliability of the animals' responses in 25 animals of six...

The prevalence of Toxoplasma gondii antibodies in wild and captive cetaceans from Japan.

The seroprevalence of Toxoplasma gondii was investigated in wild and captive cetaceans from Japan. Antibodies against T. gondii were examined by both latex agglutination test (LAT) and indirect hemagglutination test (IHAT) for 77 serum or plasma samples obtained from 59 individuals of 6 species, including 2 hybrids. Antibody titers greater than 1:64 in LAT and greater than 1:640 in IHAT, indicative of the presence of T. gondii, were found in 11.9% of 59 individuals. In 7 samples that showed a positive reaction by IHAT, T. gondii titers were examined for each immunoglobulin (Ig) fraction separated by sucrose gradient centrifugation. The antibody peaks in each fraction were divided into 3 types, thought to be a reaction of IgM (type 1), IgG (type 2), and IgM with IgG (type 3). Type 1 was found in serum from a bottle-nosed dolphin (Tursiops truncatus) and a killer whale (Orcinus orca) sampled soon after capture off the Japanese coast in 1988; it was concluded that infection in the wild had occurred less than 15 yr before the study was performed. The prevalence of putative IgM and IgG antibodies from a captive-bred T. truncatus suggested that T. gondii infection also occurred in the aquarium.

Helicobacter cetorum sp. nov., a urease-positive Helicobacter species isolated from dolphins and whales.

A novel helicobacter with the proposed name Helicobacter cetorum, sp. nov. (type strain MIT 99-5656; GenBank accession number AF 292378), was cultured from the main stomach of two wild, stranded Atlantic white-sided dolphins (Lagenorhynchus acutus) and from the feces of three captive cetaceans (a Pacific white-sided dolphin [Lagenorhynchus obliquidens]; an Atlantic bottlenose dolphin [Tursiops truncatus]; and a beluga whale [Delphinapterus leucas]). The infected captive cetaceans were either subclinical, or clinical signs included intermittent regurgitation, inappetance, weight loss, and lethargy. Ulcers were observed in the esophagus and forestomach during endoscopic examination in two of the three captive animals. In the third animal, esophageal linear erosions were visualized endoscopically, and histopathological evaluation of the main stomach revealed multifocal lymphoplasmacytic gastritis with silver-stained spiral-shaped bacteria. Helicobacter cetorum is a fusiform gram-negative bacterium with a single bipolar flagellum. The isolates grow under microaerobic conditions at 37 and 42 degrees C but not at 25 degrees C. H. cetorum is urease, catalase, and oxidase positive, and it is sensitive to cephalothin. The isolates from the wild, stranded dolphins were sensitive to nalidixic acid, whereas the isolates from the collection animals were resistant. By 16S rRNA sequencing it was determined that H. cetorum represented a distinct taxon that clusters most closely with H. pylori. Further studies are necessary to determine the role of H. cetorum in the development of gastric ulcers and gastritis of cetaceans. This is the first description and formal naming of a novel Helicobacter species from a marine mammal.

SURVIVORSHIP PATTERNS IN THREE SPECIES OF CAPTIVE CETACEANS

AbstractSurvival rates for three species of captive cetaceans are reported, based on records of dates of capture, birth, and death of individual animals. The annual survival rate was 0.93 for bottlenose dolphins and killer whales and 0.94 for white whales. Confidence limits of these estimates are discussed. Differences in survival rates between institutions were significant for bottlenose dolphins only. Calf survival for bottlenose dolphins was lower than non‐calf survival. Survivorship of male killer whales was significantly less than survivorship of female killer whales; sex‐specific survival rates were similar for the other two species. Estimates of average or maximum longevity alone were not useful in comparing rates of survival. Because survival in the first year of captivity may be lower than subsequent years, estimates of the expected lifespan, based on data from the first few years of captivity, may be biased.

Experimental vaccine against Pseudomonas pseudomallei infections in captive cetaceans

The antibody response to an experimental acellular Pseudomonas pseudomallei vaccine was evaluated by Enzyme Immunoassay in captive cetaceans at Ocean Park, Hong Kong. The vaccine preparation consisted of a protein-polysaccharide (1:3) mixture with trace nucleic acids and no 2-keto-3-deoxyoctonate. Mortality due to melioidosis was reduced over a 5 yr period from 45% to less than 1%

Tumors in Cetaceans: Analysis and New Findings

We describe 14 tumors, including 5 leiomyomas, 6 papillomas, 2 adrenal adenomas, and a bronchogenic carcinoma collected from over 1800 free-ranging and captive cetaceans examined since 1973. These bring to 41 the number of confirmable tumors reported from cetaceans. Of the 52 cases previously reported, 23 were described in sufficient detail to confirm the diagnoses, 15 were considered probable, and 4 were reclassified. Organ systems most commonly affected were the gastrointestinal tract (31%), skin (24%), and female reproductive tract (21%). Sampling bias may account for this apparent trend. Etioiogic agents have rarely been identified, and attempts to do so are hampered by inadequate sample sizes.