Researchers are using bluegills to detect industrial and agricultural spills in water supplies. "These little fish work with humans for a Big, mutual good," wrote David Kagan in Sunstroke and Doomwatch. "Who better than a fish to judge water quality?"

The emperor thought it would be a good idea to introduce Bluegill from American to the largest lake in Japan and it is wreaking havoc.

The distinctive swimming technique of a bony fish is being used to develop agile,propellerless submarines. US researchers have created prototype mechanical fins that mimic the movements of the bluegill sunfish.The robo-fins could recreate the fish’s powerful forward thrust and its manoeuvrability,the Massachusetts Institute of Technology team said

Bluegills Are a Breed of Fish So Sensitive to Water Problems That Scientists Want to Mimic Their Skills With Technology

The common bluegill fish is being used to protect public drinking water for millions in the United States from terrorists and accidental contamination.