Describe three human activities that threaten aquatic habitats?

1) Dumping of wastes and debris in the ocean. Aquatic organisms can ingest hazardous substances from human wastes; other animals also get entangled to plastics and other waste products.
2) Use of Pesticide. Increases mercury among fish species.
3) Unsustainable fishing practice. The use of fishing techniques like dredging and trawling reduces fish stock and damage marine habitats on the sea floor.

The answer is observations and interpreting.