Table 1.— Geometric mean regression equations calculated from 1977 displacement volume 

 (DV) and dry weight (DW) measures for each area by season, each individual area, and for all 

 values combined. Also included is the equation for phytoplankton-dominated stations. 



placement volume to dry weight. It was found 

 that a change in the biomass relationship oc- 

 curred between years in the six seasons that pre- 

 dictive accuracy was lowest. This was deter- 

 mined by calculating regressions with 1978 data 

 (Table 2) and comparing them with the corre- 

 sponding 1977 seasonal equations. Year-to-year 

 differences (P<0.05) in slope and/or elevation 

 were evident for the following: GB early-mid- 

 autumn, GB late autumn, GOM mid-late sum- 



mer, GOM midautumn, SNE late winter, and 

 SNE late spring-early summer. After perusal of 

 sample contents, sampling dates, and sample 

 species abundance, it was apparent that year-to- 

 year changes in these factors were correlated 

 with the 1977-78 differences in the regression 

 equations mentioned above (Tables 3-5). 



For those areas where no change in the rela- 

 tionship between displacement volume and dry 

 weight occurred between years, data was com- 



Table 2.— Geometric mean regression equations derived from 1978 displacement 

 volume (DV) and dry weight (DW) values for each area by season and for samples 

 with abundant siphonophore fragments. 



635 



