Dr. Edith Widder is a marine biologist who shines a light on pollution.
Bioluminescent bacteria are what create the magical effervescent light shows of the sea, the spectacular fireworks displays far down under water where there is no natural light. This bacteria, like everything else in the ocean, is seriously polluted.
Dr. Widder mixes this bacteria with sediment to see how toxins have affected a given area. If it is toxic, the light will not shine.
Sad as it is, this helps scientists to map out the toxic underwater areas, where the most insidious pollution is damaging our planet.