Abstract
Eye disorders is a life-threatening for pinnipeds, such as sea lions and seals, that are rely on vision for feeding. It is suspected that such as ultraviolet light, trauma on cornea and water quality may causes of ophthalmological diseases for marine mammals. In this study, we focused on the water quality, to conduct comprehensive analysis of bacteria, to clarify the bacteriological characteristics of each animal pool waters in aquarium and to search for the cause bacteria of eye disease. Bacterial 16s rRNA was investigated using a next-generation sequencer to perform community analysis of pool waters of pinnipeds and cetaceans in Otaru Aquarium. As a result, there were few opportunistic but cause bacteria of eye disease, such as Staphylococcus aureus, Serratia or Welsh bacteria. Other infectious bacteria were not recognized that those are directly cause of some diseases or other bacterial infection in public health. Three bacterial phyla were found in common with the former seawater, such as Proteobacteria, Bacteroidetes, and Firmicutes, but Fusobacteria and some non-culturable bacteria were characteristic of animal pool waters. In addition, it was found that the composition of the bacteria is different depending on each animal, so that the bacterial flora may be affected by each animal excretion. So, it is necessary to survey the bacterial flora of pool water, but important to take measures to prevent damage on the cornea of captive marine mammals, which will be an invasion route of bacteria.
