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N. Ungaro and G. Marano
Table 2. Margaleff richness index (D), Shannon-Wiener diversity index (ll) and Pielou's evenness index (j): mean values (mean,
SD, min., max.) for the Southern Adriatic Sea (shelf, slope, whole area). * , significantly different (P results, Tukey test
Southern Adriatic Sea
Depth strata Samples Dmean
SD
Dmin Dmax
Hmean
SD
Hmin Hmax
Jmean
SD
Jmin Jmax
Year 1996
10-200 m
75
2.14*
0.61
0.82 3.21
2oo-800m
37
2.59
0.67
0.96 3.64
10-800 m
112
2.29*
0.66
0.82 3.64
Year 1997
10-200 m
75
1.88>10.52
0.70 3.78
200-800m
37
2.48
0.45
1.35 3.28
10-800 m
112
2.08>10.57
0.70 3.78
Year 1998
1O-200m
75
2.48>10.53
1.36 4.48
200-800m
37
2.54
0.55
0.66 3.86
10-800 m
112
2.50>10.54
0.66 4.48
Sea did not show a clear trend over the triennium 1996-98, in spite of some differences among
the years. The main changes concern the "shelf"
ecological indices, while the "slope" situation
1996
1.49
0.44
0.41
2.34
0.58* 0.15
0.18 0.84
1.77
0.39
0.90
2.46
0.72
0.14
0.30 0.95
1.58
0.44
0.41
2.46
0.63* 0.16
0.18 0.95
1.53
0.39
0.44
2.42
0.68
0.17
0.19 0.93
1.84
0.29
0.83
2.32
0.72
0.11
0.43 0.88
1.63
0.39
0.44
2.42
0.69
0.15
0.19 0.93
1.84>10.34
0.67
2.54
0.569 0.12
0.26 0.89
1.86
0.37
0.64
2.40
0.75
0.09
0.51 1.00
1.85>10.35
0.64
2.54
0.71
0.11
0.26 1.00
appears to be reasonably stable. East (Albania)
"shelf" values are generally higher and more
homogeneously distributed than West shelf
(Italy) ones.
1998
3.e
3.1
2.8
2.1
Fig. 2. Distribution per year of richness values (Margaleff
index)