I suspect there are some good academic papers on this topic, but perhaps not?
If so, then I like your proposal that WE perform some actual science!
I did learn long ago in 7th-grade biology that spontaneous generation is not possible ... so we can at least rule that one out.
The French study that azteca linked does suggest avian transport and stocking of fish. However, that study relies heavily on indirect methods of determining that birds were the stocking vector.
I like your direct study ideas.
