Maybe you have already, but I think you should focus on hunting down the people in academia or research that already use perl for data science, and try recruiting them to come to the conference. Especially any that might never have even thought about attending a Perl conference. While I find science topics interesting, my day job is all about web apps, so I'm likely to attend those if forced to decide between competing talks.

I have no idea where you find these people, other than maybe spreading flyers around research buildings in college campuses.