Vertical distribution of gelatinous macroplankton in the North Pacific observed by manned submersibles Mir-1 and Mir-2

The vertical distribution of several medusa species in the Kurile-Kamtehatka region of the Pacific Ocean is described. Animals were observed in the light cone from deep-sea submersibles Mir-1 and Mir-2 throughout the water column, from the surface to 5000-6000 m at four different sites. Bathy- and abyssopelagic species are noted along with the species living in an extremely wide depth range. A faunistic border is re vealed at a depth of 3000 m. The contribution of gelatinous animals (medusae, submersibles, siphonophores, salps) to the total deep-sea plankton biomass was estimated using a abundance, biodiversity. wire reference cube during nine dives in the highly productive areas of the northwest Pacific, eastern Pacific (California, Costa-Rica Dome), and subtropical oligotrophic areas.