The physical effects of infrared radiation, visible light, and sonar on specific vent organisms will be observed in isolated experiments outside of the vent environment.

The Edmond Hydrothermal Vent System is located at a depth of 3000 m. At this depth, there is almost no visible light. Unfortunately, the primary means of human observation of biological systems is through visual imaging. Though it is certainly possible to flood the vent site with powerful lights, this may produce many changes in the ecology of the vent system.

Bresiliid shrimp with light-sensitive eyes have been found at vent sites on the Mid-Atlantic range at depths of up to 3500m . This suggests that there may be other light-sensitive organisms at or near the vent that would be significantly affected by a major increase in ambient light intensity at the vent. In addition, bioluminescent organisms may be permanently or transiently present at or near vent systems, and the addition of external lighting to the environment may impair their life functions.

Similarly, adding large amounts of infrared radiation or sound to the vent environment is likely to have a significant effect on the organisms living there. However, despite the inevitable impact, it is necessary that we have some way of observing the vent system. We therefore want to determine the type of radiation and exposure pattern that will have the least effect on the vent system. With this knowledge, we will then be able to design our Atlantis II observation techniques to be as un-intrusive to the vent ecosystem as possible.

It would be almost impossible to test the effects of visible light, infrared radiation, and sonar on the vent environment prior to placing Atlantis II at the Edmond Vent Site. Long term experimentation is necessary to establish the effects of prolonged exposure to these forms of imaging, and this is not possible until the habitat is in place. It is therefore impossible to determine beforehand the best means of imaging the vent site. We therefore decide to use visible light as it is media with the fewest operational problems. Light exposure and intensity will be kept to a minimum, and the effects of the light on the vent environment will be monitored. If significant damage is noted, changes will be made appropriately.

Chamberlain, Steven C. 2000 Vision in hydrothermal shrimp. Phil. Trans. R. Soc. Lond. B 355, 1151-1154.