Table 2.1. Values of the two response variables of dolphin acoustic behaviour collected by calibrated hydrophone (average
clicks and whistles per minutes) by size of group, behavioural
state and time of day during baseline and impact monitoring periods. (The numerical values highlighted in blue
indicated that the values recorded in impact monitoring period have triggered
the Action Level (20% higher or lower than the baseline period), while the ones
highlighted in red indicated a triggering of Limit Level (40% higher or lower
than the baseline period). Only the cells highlighted in yellow have found significant
differences between the values recorded in impact and baseline monitoring
periods, while no significant difference was found in other comparisons even
though some have triggered the Action or Limit Level.)
|
Average clicks per
minute ( ± s.d.) |
Average whistles per
minute ( ± s.d.) |
|
Group Size |
|||
1 dolphins |
Baseline |
62.19 ± 77.73 (n=21) |
0.21 ± 1.49 (n=19) |
Impact |
119.11 ± 201.67 (n=11) |
0.13 ± 0.30 (n=11) |
|
2-5 dolphins |
Baseline |
54.03 ± 179.32 (n=82) |
0.56 ± 1.70 (n=126) |
Impact |
54.17 ± 95.45 (n=46) |
0.09 ± 0.20 (n=46) |
|
6-9 dolphins |
Baseline |
118.00 ± 310.31 (n=23) |
1.58 ± 4.63 (n=38) |
Impact |
106.06 ± 199.58 (n=26) |
0.97 ± 1.99 (n=26) |
|
10+ dolphins |
Baseline |
289.33 ± 140.58 (n=20) |
2.74 ± 1.99 (n=36) |
Impact |
n/a |
n/a |
|
Behavioural State |
|||
Feeding |
Baseline |
30.95 ± 69.90 (n=16) |
0.62 ± 1.33 (n=29) |
Impact |
19.30 ± 29.62 (n=11) |
0.16 ± 0.26 (n=11) |
|
Milling |
Baseline |
71.29 ± 205.44 (n=90) |
0.66 ± 1.85 (n=139) |
Impact |
80.09 ± 136.86 (n=54) |
0.18 ± 0.60 (n=54) |
|
Socializing |
Baseline |
287.48 ± 326.22 (n=20) |
3.78 ± 4.14 (n=26) |
Impact |
213.12 ± 309.71 (n=7) |
2.48 ± 3.16 (n=7) |
|
Traveling |
Baseline |
13.16 ± 208.94 (n=11) |
0.25 ± 1.48 (n=12) |
Impact |
52.34 ± 32.53 (n=7) |
0.17 ± 0.29 (n=7) |
|
Resting |
Baseline |
0.10 ± 70.35 (n=2) |
0.13 ± 1.43 (n=6) |
Impact |
n/a |
n/a |
|
Time of day |
|||
|
Baseline |
38.14 ± 69.90 (n=15) |
0.70 ± 1.33 (n=29) |
Impact |
74.39 ± 124.79 (n=31) |
0.32 ± 0.75 (n=31) |
|
|
Baseline |
79.97 ± 144.51 (n=68) |
0.68 ± 1.86 (n=94) |
Impact |
110.73 ± 218.62 (n=26) |
0.66 ± 1.78 (n=26) |
|
|
Baseline |
159.41 ± 303.43 (n=44) |
1.74 ± 3.80 (n=62) |
Impact |
43.35
± 72.50 (n=17) |
0.03
± 0.08 (n=17) |
|
|
Baseline |
65.40 ± 140.58 (n=17) |
1.16 ± 1.99 (n=36) |
Impact |
49.90 ± 69.04 (n=12) |
0.42 ± 1.20 (n=12) |