this community. The major reason for this is that midwater 

 trawls fail to capture a significant part of the fauna. Active 

 nekton, e.g., squids and larger fishes are able to avoid the 

 nets. Many gelatinous zooplankton are either damaged beyond 

 recognition or they pass through the net because of their 

 fragility. Here, we report the first detailed description of the 

 vertical distribution of midwater animals based on direct in-situ 

 observations made using the Johnson Sea-Link submersibles. 



The study reported here was conducted near the shelf edge 

 off New England, just south of Woods Hole, in 800 m of water. 

 This region is referred to as the Slope Water Region (Backus and 

 Craddock, 1977; Backus et al . , 1977) and is known to be a mixture 

 of shelf water and Gulf Stream water (Iselin, 1936). 



METHODS 



Twenty-three dives were made to depths of 800 m using the 

 Johnson Sea-Link I and I_I manned submersibles (described by 

 Youngbluth, 1984). Nine dives were made from 30 August to 6 

 September 1986 and 14 dives from 2 to 9 August 1987 in three 

 submarine canyons (Atlantis, Hydrographer, and Veatch) south of 

 the Grand Banks off the New England coast (Fig. 1). The dives 

 were of 3-4 hours duration. They were made to depths ranging 

 from 400 to 800 m and usually included the entire water column. 

 It should be stressed that more time was spent at the deepest 

 depths and thus some bias is present in the data. Dives were 

 made between 1200 and 1500 hrs, and 2000 and 2300 hrs EDST so 

 that diel vertical migrations could be documented. 



During each submersible dive observations on the fauna as 

 well as depth and temperature were narrated onto audio tape by 

 audio recorder. Color video was recorded on 3/4-inch tape. 

 Following each dive videotapes were reviewed and discussed by 

 observers and the sound track transcribed. Specimens, even very 

 fragile ones, were successfully collected using several kinds of 

 samplers (described by Youngbluth, 1984). Because of the large 

 volume of the samplers, specimens experienced relatively small 

 temperature changes (<5°C) when brought to the surface. 

 Specimens were kept in shipboard incubators at ambient 

 temperatures until studied (usually within 1-3 h). 

 Representative specimens were photographed and preserved, where 

 possible. The data reported here are limited to the 

 macrozooplankton ( >2 cm long), because smaller specimens could 

 not be adequately visually quantified. 



Scuba dives were made in the upper 20 m to document the 

 epipelagic fauna. 



Water temperatures in the upper 800 m ranged from 4.8 to 

 18°C with a well marked thermocline in the top 25 m (Fig. 2). 



266 



