Mermaids (half-human, half-fish beings) exist as real, living creatures.

Caveats

• The argument that unexplored ocean territory could harbor mermaids is an argument from ignorance — the existence of undiscovered species does not constitute evidence for a specific mythological creature that violates known evolutionary biology.
• At least one source (Cewekbanget.id) falsely claims NOAA 'confirmed mermaid habitats,' which is directly contradicted by NOAA's own public denial and constitutes misinformation.
• Cross-cultural mermaid sightings are well-documented to originate from misidentification of real marine mammals (manatees, dugongs, seals) and from a fictional mockumentary ('Mermaids: The Body Found') that prompted NOAA to issue a formal clarification.