Researchers have already determined this is not the result of a human with a personal vendetta against seals and eels because all the cases were reported from remote islands that are only frequented by scientists. Littnan said he does have a few theories about how an eel could naturally end up wedged in a seal’s nostril.
https://www.boston.com/news/animals/2018/12/07/hawaiian-monk-seals-eels-noses/