Ambient light emission from hydrothermal vents on the Mid-Atlantic Ridge

A spectral imaging camera was used to observe light emission from high-temperature, deep-sea vents at three hydrothermal sites on the Mid-Atlantic Ridge (MAR): Logatchev, Snake Pit, and Lucky Strike. Ambient light measured at these sites is similar to that observed at sites along the East Pacific Rise and the Juan de Fuca Ridge, with components from both thermal and non-thermal sources. The shrimp species Rimicaris exoculata, which is found on the MAR but not in the Eastern Pacific, possesses a unique photoreceptor capable of detecting low light levels. It is not yet known if R. exoculata "sees'' vent light. However, since the characteristics of vent light appear to be unrelated to geographical location, the exclusion of R. exoculata from the Eastern Pacific is probably unrelated to differences in ambient light conditions.