If you want to practice catch and release the correct way, then get yourself an Environet.

The brainchild of the late Dave Irvine, a dedicated, thinking angler who really cared about the survival of his favourite species like bass, cod and jacks, the Environet has no knots to damage the fish's all-important mucus layer, the mesh is fine enough to let the water flow through, but not so large that fins can become frayed, and hooks don't get caught up in it either.