Macro camera temperature logger array for deep‐sea hydrothermal vent and benthic studies

Abstract

Long‐term observations of faunal communities are essential to identify biological and ecological key phenomena. Observational studies of deep sea habitats such as hydrothermal vents, however, have been restricted by technological limitations. Here we describe our recently developed instrument SMOKE (Submersible Macrophotography Observation Kamera Equipment) that was used for time‐lapse macrophotography synchronized with temperature readings for up to 28 h at 2200 m depth. Lighting was provided by a novel low‐cost white LED array powered by AA or AAA batteries embedded in epoxy within an aluminum case. SMOKE was successfully deployed at the Juan de Fuca ridge in the Northeast Pacific and delivered fine‐resolution pictures as well as centimeter‐scale temperature readings in diffuse vent flow habitats of small motile invertebrates. We found high spatial temperature changes within faunal assemblages and could identify and track specimens down to a size of 2 mm. SMOKE is also characterized by low fabrication and maintenance costs and a straight‐forward, reliable design. Overall, this device proved to be a valuable tool for macrofaunal observations linked with temperature changes over extended time periods.