With everyone talking about the look of the spino I feel people are missing a more pressing issue.

There doesn't seem to be any fencing or barriers keeping these spinosaurus that are in the water from going away from the island. Same with the Mosasaurus.

What is keeping them island bound?

We know that from the trailer the island is somewhere vaguely nearby Barbados putting it in the Atlantic somewhere in the carribean which means it's not that far for a dinosaur to potentially swim to another island so how have they not potentially migrated in the several decades since jurassic park? Or even island hopped to the mainland?

Again because this is original jurassic park there's no concept of invisible fence barriers etc either. It's gotta be the original 80s/90s tech for this super secret test facility.