Facilities that are licensed with the United States Department of Agriculture must be in compliance with the Animal Welfare Act. Subpart E of the Animal Welfare Act has regulations specific to marine mammals. The marine mammal regulations cover indoor and outdoor facilities, space requirements, feeding, water quality, employees or attendants, separation, veterinary care and transportation.
The intent of the Act is to ensure water in the primary enclosure is not detrimental to the health of the marine mammal contained therein. While the AWA regulations and standards require testing for anything added to the water (§3.106(b)(3)) there are no specific requirements to test for byproducts of disinfection. When water is chemically treated, the chemicals added must not cause harm or discomfort to the marine mammals. Byproducts of disinfection may be produced when ozone, chlorine or bromine are used to oxidize compounds in the water when dissolved organic material is present. Carbon-containing byproducts such as trihalomethanes, which may include chloroforms or bromoforms, could reach levels high enough in the water to cause liver damage.2,4,5 Some of these compounds are volatile and may be found in significant levels at the air-water interface, posing a risk of inhalation by the resident marine mammals.2 More complex carbon byproducts might reach significant levels over time if the pool water is changed infrequently.2 Nitrogen-containing compounds such as the various chloramines, especially nitrogen trichloride, are irritating to mucous membranes and eyes.2,3,4,5 Source water from some municipal water systems may contain harmful compounds in acceptable levels for drinking water, which could be harmful for animals that live in that water. Other compounds could concentrate over time in managed marine mammal life support systems where evaporative water is constantly replaced but substantial water changes are rare. Some compounds may accidentally enter the water supply. Perchlorate, bromate, lead, and algae toxins are examples of such compounds. Byproducts of disinfection and toxins present in source water may reach harmful levels in marine mammal pools but may not be routinely identified or measured.
Ocular problems are common in captive marine mammals and may be related to exposure to excessive UV light, water quality problems, trauma, or nutritional deficiencies.1 Creating pools and enclosures that are minimally solar-reflective, reminding trainers and keepers to never force their animals to look at the sun when feeding or training, maintaining optimal water quality, providing wholesome diets that include protective anti-oxidants, and providing strategic shade may all help to ensure the next generation of captive marine mammals do not suffer premature ocular disease.
I thank Drs. Ed Latson, Barbara Kohn and Nora Wineland for their assistance.
* Presenting author
1. Gage LJ. Captive pinniped eye problems, we can do better. J Mar Anim Ecol. 2011;4(2):25–29.
2. Latson FE. Concerning oxidant levels in life support systems. www.centralparkah.com/images/oxidant_in_LSS_3.pdf.
3. Latson FE. Byproducts of disinfection of water and potential mechanisms of ocular injury in marine mammals. What you can't see might hurt them. In: Proceedings from the 40th Annual Meeting of the International Association for Aquatic Animal Medicine; May 2–7, 2009; San Antonio, TX. 186–188.
4. Liviac D, Wagner ED, Mitch WA, Altonji MJ, Plewa MJ. Genotoxicity of water concentrates from recreational pools after various disinfection methods. Environ Sci Technol. 2010;44(9):3527–3532.
5. Plewa MJ, Wagner ED, Mitch WA. Comparative mammalian cell cytotoxicity of water concentrates from disinfected recreational pools. Environ Sci Technol. 2011;45(9):4159–4165.