he summarizes the patterns of depth distribution seen for 

 gelatinous plankton and crustaceans on the 11 dives made in 1987. 

 The abundance of animals was less in this oceanic environment 

 than Larson et al. reported from the canyons, but similarities in 

 species occurrences and distributions were apparent. A number of 

 probable new species were collected during these dives also, 

 including a large and unusual medusa found near the bottom. 



The midwater studies discussed here have been largely 

 observational, with backup on film and videotape of visual 

 sightings. Quantification of these observations is a serious 

 problem in midwater, because there is usually no frame of 

 reference outside the submersible to provide a scale for the 

 abundance or distribution of organisms. Spatial relationships 

 between objects are difficult to record, and human observers have 

 trouble keeping more than one organism in view at a time. 

 Hamner, Prewitt and Kristof describe equipment for recording 

 video images in three dimensions, so that a stereoscopic field of 

 view can be reconstructed later for visual or automated analysis. 

 A preliminary version of this equipment was used on the Pisces VI 

 during the Beebe project to record 3-D images of sharks on the 

 bottom. Applied to midwater observations, the system will permit 

 the detailed analysis of density of organisms, their positions 

 relative to one another and the speed and pattern of their 

 movements, all within a defined volume of water. Hamner et al. 

 describe two sets of hardware under development, as well as some 

 general considerations for stereoscopic video systems and 

 automated motion analysis. 



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