I want to know the answer to the following question:
What has a role in the dispersal of propagules of plants and plankton?
All the background I'm provided with is that "Due to the global spread of avian influenza, bird migration has been studied as a possible mechanism of disease transmission, but it has been found not to present a special risk; import of pet and domestic birds is a greater threat.". Is that enough to answer the question?
Answer: no