Marine biologist Douglas Denver, claims that after conducting a secretive underwater study, he's seen proof that dolphins have a sophisticated underwater communication network using discarded fishing nets and clamshells.
The system, which stretches for thousands of kilometres underwater, is used by the dolphins' ability to determine underwater currents, they then chat' into empty clam shells and attach them to the nylon network. They can send messages to other dolphins, hundreds, or even thousands of miles away.
It had previously been believed that dolphins had the ability to communicate over hundreds of miles via sonar. This has now been rubbished by the scientific community after Denver's discovery, and the U.S. government has ordered the destruction of all research into sonar. It has also recalled millions of dollars in grants issued for sonar research.