STUDY OF BIOLUMINESCENCE IN DEEP SEA

This study beg;m with the preliminary testing of t.hc DUMAND (Deep Underwater Muons Awl Neutrino Detector). In t.hc preliminary test for t.hc DUMAND, huuincsccuce was detected at depths of 1500m to 4700m near Hawaii Island by photomultipliers. Measurement was conducted with the detectors suspended from t.he ship or tethered to t.hc sea bottom. The mean value obtained from the detector tethered to the sea bottom were about 1/10 of the value obtained from the detector suspended from the ship. We came to the conclusion that there is a very high chance that such luminescence exists in all deep water throughout the world's seas. Using a. photon counting system which employs a video camera, we found that many lightcmit.t.iug point sources exist in the surface sea water at Okayama. We also examined how the light intensity changed wit.h depth by sampling water from different depths down to 3500m and analyzing them on board. Video images showed that luminescence in t.hc deep sea came not only from point. sources but. also from some sizable objects. We arc very interesting to study why such mauy luminescence organisms exist in all over the world deep sea and also to study environmeut.-rclatcd issues of the luminescence.