When a project is imported, metadata of who imported it is available on the Projects page in the UI, and accessible via the API. You're able to see the name, email address and avatar of the user, if there is one. It's possible that older projects don't display this data, but any projects you import today do.
If you want to add an owner to a project, do so via the UI and API. On a project page, you pick from a list of everyone who has access to that project – meaning, everyone who is a member of the org. At the moment, this data is only visible on the project page and on the projects endpoint, in the API – but we plan to expose it to other areas in Snyk in the future, such as use in reporting and custom notifications.