Although they may not look like it, many animals belonging to the phylum Cnidaria actually have a quite significant economic importance for humans, especially those belonging to the Anthozoa class. For instance, scientists have discovered many chemical compounds in Cnidarians that can be used to treat cancer and other illnesses.
All species of coral are also Cnidarians. They provide an important habitat for a huge number of commercially fished species, including crustaceans and other invertebrates, fish, algae, seaweed and more. These coral reefs also have a huge economic impact due to tourism as well, as people flock to the reefs for snorkeling, diving and other activities. There is also a large worldwide trade in coral for aquariums and jewelry, but much of this has resulted in the destruction of many of these resources.
Many Cnidarians are also an important part of the food chain for larger, commercially fished animals, many of which could not exist without them to feed on.
Cnidarians also have a few negative economic impacts as well, such as the closing of beaches due to jellyfish swarms. These swarms also often clog the nets of commercial fishing boats, costing them time and money. Furthermore, jellyfish stings can put people in the hospital or even result in death, further adding to their costs.