Reading about the SSWD virus that travels through the water made me wonder about other pathogens riding the water and if they might be harmful to humans. I found that a bacteria that infects fish, Mycobacterium marinum, can be transferred to humans from contact with fish and dolphin bites. It was first isolated in saltwater fish, then was found in freshwater fish, and in 1951 Norden and Linnel recognized it as a cause of human disease when they isolated it from skin lesions in swimmers (http://annals.org/article.aspx?articleid=694731). It's sometimes misdiagnosed as skin TB in humans, and it's closely related to M. tuberculosis.
It is nonlethal in humans and causes skin lesions on cooler parts of the body, such as hands, knees, and elbows. Growing interests in fish farming and in keeping tropical fish as pets may have caused the increase in human infections of M. marinum. A genome fingerprinting study found seven isolates from captive and wild marine fish, two from captive freshwater fish, and one marine isolate from a hawksbill sea turtle.
(http://iai.asm.org/content/62/8/3222.short) <for later
(http://jcp.bmj.com/content/23/6/475.full.pdf+html) <The poor sap that got fish TB from a dolphin
(http://www.sciencedirect.com/science/article/pii/S0020751902000693) <Because I thought this was cool
WHAT? Parasites from cats are killing sea otters? Nobody buy flushable kitty litter!