Its been coming, fish food without the fish. 
 
Dartmouth scientists have created a more sustainable feed for aquaculture by using a marine microalga co-product as a feed ingredient. The study is the first of its kind to evaluate replacing fishmeal with a co-product in feed designed specifically for Nile tilapia.
 
Story link: Making aquafeed more sustainable: Scientists develop feeds using a marine microalga co-product (phys.org)