Investigation of the Marine Mammal Immune System
Although much progress has made, there is still much information to be gained on the marine mammal immune system. Many of the reagents that are available to study the immune system of terrestrial mammals cannot be used to investigate the marine mammal immune system. Our research team has focused on studying the bottlenose dolphin and beluga whale immune systems and have developed dolphin and whale-specific tools and reagents to characterize the cetacean immune system. These include molecular probes, functional assays and cell markers. Mystic Aquarium scientists are also cloning genes of interest from marine mammals. Cloning genes enables the comparison of immune sequences between marine mammals and humans and/or other terrestrial mammals to gain insight into the evolution of these important proteins and the immune system. By studying the immune system of marine mammals we may also gain important information on the human immune system.
Measurement of hormones in the blood, saliva and feces of Beluga whales
Mystic Aquarium scientists are studying hormones or chemical messengers in the blood that play major roles in metabolism, reproduction and adrenal response in beluga whales. Feces, saliva and more recently exhaled breath have been used in many species to monitor hormonal activity and Mystic Aquarium scientists are investigating the feasibility of measuring hormones in saliva, blow and feces of belugas as an alternative to blood collection. The goal is to transition the techniques to sample free ranging whales such as obtaining breath samples from endangered whales to determine reproductive and health status.
Circulating levels of thyroid hormones in beluga whales
Mystic Aquarium scientists determined whether circulating levels of total thyroxine (tT4), total triiodothyronine (tT3), and thyroid stimulating hormone (TSH) are subject to biological and environmental influences as a function of age, sex, or season in aquarium belugas and if these hormones reveal any significant metabolic adaptation in wild beluga whales.
To date, because no accurate ranges exist for reference, thyroid hormones in beluga whales have been poorly explored and under-utilized. The data gained from this project is an important first step in our understanding of thyroid hormones in this species. This research provides baseline T3, T4, and TSH levels for thyroid health monitoring and comprehensive health assessments in both aquarium-maintained and wild belugas.
Molecular signatures of health in marine mammals
Mystic Aquarium scientists are developing molecular tests to identify genes that play a critical role in marine mammal health. Investigations of these markers in both blood and skin can reveal important information such as health consequences of exposure to environmental stressors e.g. chemical or noise pollution. Mystic Aquarium scientists are also investigating the feasibility of skin as a health assessment tool through this study, since for free ranging marine mammals skin can be obtained through remote biopsy.
The Impact of Marine Origin Brucella on Marine Mammal and Human Health
Brucella, a bacterial pathogen known for centuries for its devastating reproductive and general health effects in humans and livestock, is now recognized in marine mammals. Limited knowledge is available on its full physiologic effects in marine mammals. Though similar to terrestrial origin brucellosis, marine origin Brucella infection will likely act as a significant factor in low conception rates and increased spontaneous abortion and stillbirth rates in marine mammal populations. Marine origin Brucella is also zoonotic, thus poses a threat to humans who come into close contact with marine mammal body fluids and tissues, such as researchers, veterinarians, and animal care specialists.
To appreciate the potential for health problems associated with marine origin Brucella, we must understand the magnitude of the problem in marine mammal populations. Past studies involving marine mammal brucellosis have used traditional livestock diagnosis methods, and the results are frequently inconsistent. Thus this disease has likely been under-diagnosed in marine mammals, and the true impact of infection has not been properly accounted for in studies that seek to document significant causes of population decline in marine mammal populations. The diagnosis of marine Brucella exposure in humans uses techniques similar to those in veterinary medicine, likely repeating the problem of under-diagnosis.
Scientists at Mystic Aquarium use multiple diagnostic tools, including culture, PCR , and newly developed serological studies to improve our knowledge of the past and present prevalence of marine origin Brucella exposure/infection and its effects in both wild and marine mammals in professional care.
Impacts of Diving on the Immune System of Marine Mammals
In recent decades there have been increasing reports of marine mammal strandings and disease leading to questions over whether human activities are negatively impacting marine mammal health. There is concern that human activities may serve as stressors, interrupting adaptations to diving in marine mammals and leaving them more susceptible to injury and disease. This has highlighted the need to further understand the relationship between marine mammal health, environmental challenges and human activities.
Mystic Aquarium scientists are studying how marine mammal immune cells function during diving and how additional stressors may alter this function, thus impacting marine mammal health. Blood samples are exposed to simulated dives using a small pressure chamber, and the response of immune cells to changes in pressure are measured. Blood samples are also being obtained from Aquarium whales after diving with activity and without to determine impact on the immune system and health.
Discovering the Mating System of the Beluga Whale
Beluga whales are important ambassador residents of public aquaria throughout the world, holding the torch for the conservation of Arctic ecosystems in the face of climate change. To ensure that public aquaria can share that conservation message with visitors for decades to come, public aquaria cooperate to encourage breeding of resident whales to develop aquarium populations in an environmentally sustainable way. However, there are many unknowns to the mating systems of beluga whales, especially behaviorally: The repertoire and sequence of courtship behavior and vocalizations are unknown; it is unknown how animals signal interest, receptiveness, or readiness to mate to potential partners; it is unknown how courtship behaviors influence hormonal staging for reproduction and pregnancy or how hormonal state influences courtship and reproduction behavior; and it is unknown how mate choice is expressed or exerted behaviorally. Mystic Aquarium scientists and collaborators are addressing these knowledge gaps by observing behavior and recording vocalizations of courting and breeding whales in aquaria; and by tying those behaviors to known reproductive stages as measured by reproductive hormonal cycles. Uncovering the secrets of the beluga mating system will be useful to wildlife managers in making management decisions to support breeding behaviors among wild populations of belugas.
Aquaculture of Marine Ornamental Fishes
The marine aquarium industry is bustling: 1.5 to 2 million people worldwide keep marine aquaria, trading up to 57 million individuals and 2,100 species of fish, invertebrates, and corals annually, and supporting a trade that has an annual worldwide economic impact of up to $330 million. However, 98 – 99 % of marine species for the aquarium trade are wild-caught, posing potential threats to overfishing of wild populations and capture-related damage to marine habitats. Mystic Aquarium scientists are contributing to the research and development of aquaculture techniques of marine ornamental species working in partnership with the Marine Science Magnet High School, Groton, CT. These approaches will empower the industry to aquaculture a broader range of species, thus working toward a more sustainable hobby and industry.