Let sea creatures be. Leave seaweed and empty shells where they lie. Let coral reefs be. Almost all marine fish, corals, and other salt-water animals sold for home aquariums come from the wild. For this reason, many reef species are in danger of extinction.
Freshwater fish are a better choice because they're usually bred in captivity.
Develop a community action plan to clean up local waterways. Encourage the establishment of marine protected areas. Get together with those who have a stake in protecting oceans - coastal communities, ocean resource users, and everyone else who cares about vulnerable marine habitats. Encourage your family, friends, and community members to dispose of household hazardous wastes, such as leftover paint, motor oil, car batteries, and solvent containers, at proper waste disposal sites. Discourage them from dumping these wastes down the drain or into ordinary landfills.