. TOTAL DIATOMS CHAETOCERACEAE - -' 'PENNATAE" .ââââ... BIDDULPHIINEAE o DISCINEAE -â SOLENIINEAE n ' ' ' lio ' ' ' "" SEA MILES FROM LAND Fig. 74. Estimated total diatoms, and diatom group totals, survey I. A. Walvis Bay line, 6-8 March 1950. B. Middle Intermediate line, 9-10 March 1950. excentrica, with lesser numbers of Planktoniella sol. Biddulphiineae were present inshore and of con- siderable importance at station WS 980, but were not observed seawards of the peak station WS 979. The group was represented here entirely by Eucampia soodiacus, as on the Mowe Point line. Chae
. TOTAL DIATOMS CHAETOCERACEAE - -' 'PENNATAE" .ââââ... BIDDULPHIINEAE o DISCINEAE -â SOLENIINEAE n ' ' ' lio ' ' ' "" SEA MILES FROM LAND Fig. 74. Estimated total diatoms, and diatom group totals, survey I. A. Walvis Bay line, 6-8 March 1950. B. Middle Intermediate line, 9-10 March 1950. excentrica, with lesser numbers of Planktoniella sol. Biddulphiineae were present inshore and of con- siderable importance at station WS 980, but were not observed seawards of the peak station WS 979. The group was represented here entirely by Eucampia soodiacus, as on the Mowe Point line. Chaetoceros was by far the most important group over the Walvis Bay line as a whole. It was strongly dominant at the two richest inshore stations, where a profusion of neritic species were present, and at the first of the poorer stations, seawards. There, however, the single ' relatively oceanic' species Chaetoceros convolatum alone accounted for most of the group total. Still further offshore the group dwindled rapidly, both in estimated numbers and in relative importance. Soleniineae were present at all stations on the line in consistently small numbers, becoming relatively important in the poorest offshore plankton. Cosmopolitan Rhizosolenia spp. predominated throughout, accompanied at one inshore station, where the group total was highest, by the mainly neritic Dactyliosolen mediterraneus. ' Pennatae' were an important group on this line, especially at the innermost and outermost stations 15-2
Size: 2269px × 2203px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
