Two projects in 1987 used the Pisces VI , leased from 

 International Underwater Contractors and supported by their 

 vessel Twin Drill . Fred Grassle (WHOI) established bottom 

 stations northwest of Bermuda for time course experiments to 

 examine the effect of Sargassum falls on the diversity of the 

 benthic fauna (Grassle et al., 1988). The Pisces also was used 

 by Eugenie Clark and Emory Kristof to continue their studies of 

 six-gill sharks. Kristof and Hamner used a new 3-D video camera 

 system to obtain dramatic footage of shark feeding behavior 

 (Hamner et al . , 1988). Related work on the six-gill sharks was 

 carried out by Frank Carey (WHOI) who placed acoustic tags on two 

 sharks caught on longlines, and tracked their movements over 

 several days. 



The midwater program of the Beebe Project was conducted by 

 William and Peggy Hamner, Madin, and Robison using the Johnson 

 Sea-Link II and the R.V. Edwin Link from Harbor Branch Oceano- 

 graphic Institution. Although part of the project, Marsh 

 Youngbluth (HBOI) was unable to participate in 1987 due to 

 cruise conflicts. 



Pelagic Biology Program 



Research on midwater zooplankton and micronekton was planned 

 to include studies of vertical distribution, feeding and swimming 

 behavior, and patterns of aggregation of fish, crustaceans and 

 gelatinous animals. By diving repeatedly at the same site, we 

 hoped to characterize the vertical distribution of the fauna, and 

 monitor changes from one day to the next. In order to provide a 

 reference point in midwater, a lighted platform was moored at 

 300 m. Its lights could be used to illuminate organisms with 

 back- and side-lighting, and to act as an attractant for the 

 aggregation of planktonic animals responsive to artificial light. 

 The Sea-Link could then be used as a darkened blind from which to 

 observe animals around the platform. Unfortunately, weather 

 conditions caused about half the planned dives to be cancelled, 

 including most of the dives at the platform. 



In this paper, the author will describe the design, 

 deployment and operation of the midwater platform, summarize the 

 observations on depth distribution of midwater zooplankton, and 

 discuss some of the behavioral observations made. In a separate 

 contribution, Hamner et al . (1988) discuss the design and use of 

 stereoscopic video systems for midwater studies. A new and 

 unusual medusa collected during the dives is described by Larson 

 et al. (1988b). 



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