well. I guess that these scientists need 3-4 sharks to come to a conclusion that there are no (or very small amount) of bacteria on the shark's skin. And as it would be hard to take the samples of the skin if these animals were alive, then indeed I think that they have to kill these 3-4 creatures. And then they could just take some peaces of the skin of the same these 3-4 animals to analyse them with the microscope. So the proper description for this hunt should be "..WITHOUT any complications ...for human beings".
Indeed, tomorrow could be different. For example, there are 3D computer models of viruses, so the scientists now can analyse the viruses and select appropriate targets to block them. Maybe it will be possible (I hope so) to analyse the animals (like sharks) in such a way (on computer in 3D without killing any creature) as well )