Table 1 General information on diatom assemblages recorded in the springs of 1993, 1994 and 1995
1993 | 1994 | 1995 | |
|---|---|---|---|
Total | |||
Number of species recorded | 173 | 162 | 103 |
Mean number and range of species per station | 50 (34–86) | 51 (31–73) | 27 (16–42) |
Dominant species (mean relative abundance) | F. kerguelensis (20 %) | C. contortus (16 %) | F. kerguelensis (35 %) |
T. nitzschioides (8 %) | F. kerguelensis (11 %) | C. criophilum (15 %) | |
F. doliolus (6 %) | C. debilis (10 %) | T. nitzschioides (7 %) | |
C. rostratus (5 %) | B. hyalinum (6 %) | A. hookeri (5 %) | |
Common species (present in >70 % of the samples) | A. tabularis | A. tabularis | A. tabularis |
A. curvatulus | A. curvatulus | A. curvatulus | |
C. criophilum | C. criophilum | A. parvulus | |
T. nitzschioides | C. decipiens | F. kerguelensis | |
F. kerguelensis | F. kerguelensis | T. nitzschioides | |
TZ | |||
Mean number and range of species per station | 53 (34–87) | 57 (27–73) | 28 (18–42) |
Proportion of cold-water species | 16 % | 13 % | 25 % |
Relative cell abundance of cold-water species | 8 % | 0.9 % | 20 % |
Relative cell abundance of warm-water species | 44 % | 89 % | 31 % |
Dominant species (mean relative abundance) | F. doliolus (12 %) | C. contortus (38 %) | C. criophilum (21 %) |
T. nitzschioides (12 %) | B. hyalinum (13 %) | T. nitzschioides (13 %) | |
C. rostratus (10 %) | P. multiseries (5 %) | F. kerguelensis (10 %) | |
F. kerguelensis (5 %) | |||
SAZ | |||
Mean number and range of species per station | 41 (37–50) | 36 (31–42) | 26 (22–31) |
Proportion of cold-water species | 51 % | 49 % | 62 % |
Relative cell abundance of cold-water species | 68 % | 68 % | 89 % |
Relative cell abundance of warm-water species | 1.2 % | 4.8 % | 0.42 % |
Dominant species (mean relative abundance) | F. kerguelensis (42 %) | F. kerguelensis (37 %) | F. kerguelensis (60 %) |
C. convolutus (8 %) | C. atlanticus (11 %) | A. hookeri (7 %) | |
E. antarctica (7 %) | P. lineola (10 %) | F. ritscheri (5 %) | |
AZ | |||
Mean number and range of species per station | 48 (40–56) | 50 (38–63) | 25 (16–32) |
Proportion of cold-water species | 67 % | 62 % | 87 % |
Relative cell abundance of cold-water species | 81 % | 58 % | 97 % |
Relative cell abundance of warm-water species | 0.06 % | 1.2 % | 0 % |
Dominant species (mean relative abundance) | F. kerguelensis (37 %) | C. debilis (32 %) | F. kerguelensis (29 %) |
C. criophilum (5 %) | F. kerguelensis (19 %) | A. hookeri (22 %) | |
P. lineola (5 %) | P. lineola (8 %) | A. hyalinus (9 %) | |
P. heimii (5 %) |