Dolphins usually have positive meanings in dreams, symbolizing your connection with others and the world, and representing your communication skills.
Dreaming of sharks, which belong to marine animals, usually indicates problems in the emotional field, suggesting that people's emotional endurance will gradually lose after being violated by some bad intentions or improper behaviors. Sharks are usually associated with a common subconscious, which symbolizes the fear of death. However, this does not mean that the dreamer is in a desperate situation. Dreaming of sharks means that the dreamer has been unfairly violated, or someone wants to seize the power that belongs to the dreamer.