Naked Tuna

Q: This summer I caught a tuna with a disease called "white cloud." I had never heard of this before. Do you have any information about this disease? - Douglas Hill, Hastings-On-Hudson, New York

A: You're not the only one who has never heard of "white cloud" - neither had the Smithsonian's fish laboratory, the National Marine Fisheries Service's Highly Migratory Species office in Maryland, the tuna observer program in Miami and the Inter-American Tropical Tuna Commission at Scripps in California. I even called a friend who has worked on one of the big Northeast tuna seiners for 20 years, and he also says he's never heard of white cloud.
However, I ran across an instance of white cloud in a tuna many years ago, so I know it exists, and I ultimately tracked down one scientist who had heard of white cloud: fishery biologist Pat Scida at the NMFS Northeast regional office. "I've seen it," says Scida, "in a fish caught in Gloucester. It looked like a white discoloration of the flesh." The fish he saw that had white cloud was a bluefin tuna weighing over 200 pounds. "There's not much known about it," he says. "It's found occasionally, not frequently, in bluefin, sometime in a large section of flesh, or sometimes just in a small section."
It's probably not a disease, Scida speculates, or it would be more well-known among scientists. It might be caused by trauma - an injury to the flesh of the fish - he says. If any of our readers have more information about this phenomenon, we'd be happy to hear from you.