Dataset: Diver-collected jellies RHB-0603
Deployment: RHB0603

Collection of living or intact specimens of gelatinous zooplankton is difficult with nets or trawls because the organisms are usually damaged and sometimes destroyed. During the last 30 years, the technique of blue-water diving to make observations and collections of these fragile animals by SCUBA has been developed and this technique was used on this cruise. A group of (usually) 4 divers worked from a small inflatable boat launched from the ship. They were connected by 10 m long tether lines to a central line hanging down from the inflatable and manned by a safety-diver who watched over the others. Each diver moved about within a 10 m radius to locate, observe, and collect free-swimming gelatinous animals. The technique was only semi-quantitative, but allowed collection of live and undamaged specimens, as well as in-situ photos of behavior. Organisms were collected in simple wide-mouth jars and returned to the ship for further study. The same technique was used at night, with the addition of underwater flashlights or headlamps.