Answer:
The speaker personify the fish by given the fish a male gender and she refers the fish using the pronoun "his". Though the fish lacks emotion but she uses the adjective vulnerable to qualify the fish.
As she observed closer, she understands and share the feelings of the fish and she finally set the fish free.
Explanation:
The poem fish by Elizabeth Bishop shows the ecological awareness that made her to accept the relationship that exist between human beings and non human beings. This was shown when she set the fish free.