[quote=@rush99999]
<Snipped quote by Guardian Angel Haruki>

That just means he can't get closer to the fish. He could still do other things, right?
[/quote]

He can, but it would be at disadvantage.

[i]A frightened creature has disadvantage on ability checks and attack rolls while the source of its fear is within line of sight.
The creature can’t willingly move closer to the source of its fear.[/i]