Sometimes the water in Puget Sound glows. Why does it do that?
The glow is caused by a type of plankton and certain jellyfish. The scientific term is 'bio-luminescence'. They glow when disturbed. Scientists believe that is both an alarm to other plankton (or jellyfish) and also as a warning, since the 'glow' makes it easy for even bigger predators to spot (and eat) the predator that's eating the plankton.