Table 1. The acoustic conditions in the experimental setup in the sediment and at the interface between seawater and sediment (data were presented as means and 1st quartile to 3rd quartile of the data in the parentheses, and different superscripts indicate significant differences between trials by Tukey’s test).
| Sound level measured in air | Hydrophone position in the experimental setup |
Underwater sound intensities at distances to the center of the concentric circle of the sediment (dB re 1 μPa) |
||
|---|---|---|---|---|
| 5 cm | 15 cm | 25 cm | ||
| Control ~50dB re 20 μPa | Interface between water and sediment | 63.19a (61.91~64.41) | 62.22a (60.96~63.42) | 61.67a (60.43~62.86) |
| In the sediment | 56.13b (55.01~57.40) | 55.51b (53.91~57.68) | 54.71b (53.12~55.76) | |
| 1000Hz~100dB re 20 μPa | Interface between water and sediment | 95.55a (86.79~101.54) | 94.74a (85.71~~100.89) | 93.62a (83.86~100.60) |
| In the sediment | 87.35b (78.21~94.41) | 85.63b (77.67~89.86) | 86.93b (78.45~92.32) | |
| 1000Hz~80dB re 20 μPa | Interface between water and sediment | 87.09a (82.59~88.49) | 85.43a (82.08~86.97) | 82.15a (79.91~82.64) |
| In the sediment | 77.92b (76.54~79.44) | 77.6504b (76.28~79.21) | 77.8985b (76.38~79.11) | |
| 500Hz~100dB re 20 μPa | Interface between water and sediment | 100.87a (92.77~107.05) | 100.16a (92.19~106.54) | 96.36a (89.04~103.39) |
| In the sediment | 85.30b (79.12~89.49) | 84.94b (78.91~89.47) | 83.5212b (78.55~85.99) | |
| 500Hz~80dB re 20 μPa | Interface between water and sediment | 86.36a (84.09~86.56) | 82.19a (80.29~82.93) | 82.69a (79.09~84.48) |
| In the sediment | 77.48b (75.91~78.92) | 77.46b (75.94~78.95) | 78.59b (77.28~79.16) | |
| White noise ~100dB re 20 μPa | Interface between water and sediment | 103.25a (94.96~109.57) | 102.45a (94.30~108.97) | 102.21a (94.45~108.67) |
| In the sediment | 88.82b (82.34~93.18) | 88.34b (81.94~93.18) | 87.86b (81.49~92.17) | |
| White noise ~80dB re 20 μPa | Interface between water and sediment | 92.20a (90.34~96.73) | 91.69a (89.84~96.19) | 91.17a (89.33~95.65) |
| In the sediment | 83.09b (81.42~84.64) | 84.03b (82.33~85.59) | 84.96b (83.24~85.78) | |