Light is a critical resource for human work — and a dangerous industrial byproduct. Artificial light sources disrupt the natural behaviors of ocean life, attracting or driving away or native organisms. Early explorations of Earth's deep oceans were confounded by their own use of floodlights, which repelled the very life they were searching for.
Expanding colonies should carefully monitor their light production and changes in the behavior of native organisms. The darker it is, the more dangerous a light can be.