Okay, bear with me and take note that English is not my first language, so this might not be very technically correct.
Ours has the dowel with the ribbon as well. What we do is pull the ribbon over the fish (seahorse). There is a little hook inside that keeps it down (you have to fiddle it over it when you remove it). Then we use a ziptie to tie the two ribbon parts together and push the tied part under the fish.
Someone who would want to take it, would have to cut off the FE with scissors and I don't think many people carry some.
Ah ha! I think I understand. Just to be certain - maybe I'll just come by your staterroom first and look before hanging ours! By the way- your English is immaculate! I thought perhaps you were an expatriate - having moved to Austria from the US. I did not realize until you mentioned it that English is not your mother language. How lovely to be fluent in more than one language!