If you start in the Southern Isles (south spawn region) and head west across the shoreline you’re bound to run into one that’ll be hanging out in a river connecting a swamp and the open ocean. Just be mindful of it’s location and try to stick near the trees while watching the shoreline.
If you are having a hard time finding spino's in their respective spawn zones (especially Ragnarok), kill all the fish in that area. They share the same spawn capacity and can be out spawned by coles! ( up vote so Rag players know!!!)