5. Summary
- In this note, the results for three energy conversion factors have been presented:
- energy conversion fact of 4% reducing to 0.5% over the piling sequence;
- energy conversion fact of 1% throughout the piling sequence;, and
- energy conversion fact of 10% reducing to 1% throughout the piling sequence.
- Full tabulated results are presented in section 5.
- The results of the analysis are summarised as follows:
- all modelling results predict large TTS ranges; it is unrealistic to consider noise propagating over this distance to cause an adverse effect to marine life;
- contributions from strikes at tens of kilometres where the pulse duration of impulsive noise spreads such that it is no longer impulsive, and instead is non-impulsive in character ,is likely to lead to an overestimate of effect ranges (see appendix A); and
- noise that is no longer impulsive does not have as detrimental an impact on marine mammal receptors, and therefore the equivalent injury thresholds for continuous noise are comparatively lower.
- As stated in the volume 3, appendix 10.1, annex A, a conversion factor of 10% is considered unrealistic due to the lack of substantiated evidence of this occurring. It is considered an overestimate of the true energy radiated into the water column caused by discrepancies between the noise modelling and real-world propagation.
- It is considered, taking into account the proposed piling methodology, best scientific evidence and professional judgement, that 4% is a robust starting point for energy conversion factors for submersible impact hammers, reducing through the piling sequence, as set out in the technical note on conversion factors in volume 3, appendix 10.1, annex A and based on the detailed considerations in Lippert et al. (2017). For above water impact hammers a 1% conversion factor is considered reasonable.
- Based on this sensitivity analysis, there is a relatively small difference in predicted modelled injury ranges for most marine mammal receptor groups between the 1% conversion factor throughout the piling sequency, and a conversion factor of 4% reducing to 0.5%.
6. Full Results
- The full results of the sensitivity calculations are shown here in Annex A as follows, using a conversion factor of 1%, a conversion factor of 4% reducing to 0.5% as used in volume 3, appendix 10.1, and a conversion factor of 10% reducing to 1%:
- Injury ranges based on cumulative SEL thresholds for marine mammals, for the “maximum”, “realistic” and OSP/Offshore convertor station platform piling scenarios Table 6.1 to Table 6.3.
- Injury ranges based on peak SPL thresholds for marine mammals, for the “maximum”, “realistic” and OSP/Offshore convertor station platform piling scenarios – Table 6.4 and Table 6.5.
- Injury ranges based on cumulative SEL thresholds for fish, for the “maximum”, “realistic” and OSP/Offshore convertor station platform piling scenarios – Table 6.6 to Table 6.8.
- Injury ranges based on peak SPL thresholds for fish, for the “maximum”, “realistic” and OSP/Offshore convertor station platform piling scenarios – Table 6.9 and Table 6.10.
- Injury ranges based on cumulative SEL thresholds for marine mammals for piling of two foundations simultaneously, for the “maximum” and “realistic” piling scenarios – Table 6.11 and Table 6.12.
- Injury ranges based on cumulative SEL thresholds for fish for piling of two foundations simultaneously, for the “maximum” and “realistic” piling scenarios – Table 6.13 and Table 6.14.
Table 6.1: Injury Ranges for Marine Mammals due to Impact Pile Driving for the “Maximum” Pile Driving for Wind Turbine Foundations for the Three Energy Conversion Factors Assessed – “Maximum” Scenario Includes Piling up to 4,000 kJ (N/E Is Threshold not Exceeded)
Species/Group | Threshold (Weighted SEL) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | ||
LF | PTS - 183 dB re 1 µPa2s | 332 | 1,030 | 3,015 |
TTS - 168 dB re 1 µPa2s | 37,170 | 28,693 | 44,491 | |
High Frequency (HF) | PTS - 185 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 170 dB re 1 µPa2s | N/E | 33 | 75 | |
VHF | PTS - 155 dB re 1 µPa2s | 104 | 286 | 702 |
TTS - 140 dB re 1 µPa2s | 9,918 | 8,496 | 14,133 | |
PCW | PTS - 185 dB re 1 µPa2s | N/E | 47 | 116 |
TTS - 170 dB re 1 µPa2s | 3,020 | 3,228 | 7,584 | |
OCW | PTS - 203 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 188 dB re 1 µPa2s | N/E | 18 | 49 | |
Species/Group | Threshold (Weighted SEL) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | ||
LF | PTS - 183 dB re 1 µPa2s | 229 | 707 | 2,165 |
TTS - 168 dB re 1 µPa2s | 30,249 | 23,376 | 37,521 | |
HF | PTS - 185 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 170 dB re 1 µPa2s | N/E | 26 | 58 | |
VHF | PTS - 155 dB re 1 µPa2s | 81 | 223 | 514 |
TTS - 140 dB re 1 µPa2s | 7,671 | 6,869 | 11,796 | |
PCW | PTS - 185 dB re 1 µPa2s | N/E | 35 | 88 |
TTS - 170 dB re 1 µPa2s | 1,562 | 2,220 | 5,754 | |
OCW | PTS - 203 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 188 dB re 1 µPa2s | N/E | N/E | 37 | |
Table 6.3: Injury Ranges for Marine Mammals due to Impact Pile Driving for the Pile Driving for OSP/Offshore Convertor Station Platform Foundations for the Three Energy Conversion Factors Assessed – OSP/Offshore Convertor Station Platform Scenario Includes Piling up to 4,000 kJ (N/E Is Threshold not Exceeded)
Species/Group | Threshold (Weighted SEL) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | ||
LF | PTS - 183 dB re 1 µPa2s | 325 | 1,023 | 2,977 |
TTS - 168 dB re 1 µPa2s | 35,030 | 27,519 | 42,801 | |
HF | PTS - 185 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 170 dB re 1 µPa2s | N/E | 33 | 75 | |
VHF | PTS - 155 dB re 1 µPa2s | 103 | 285 | 699 |
TTS - 140 dB re 1 µPa2s | 9,460 | 8,317 | 13,791 | |
PCW | PTS - 185 dB re 1 µPa2s | N/E | 47 | 116 |
TTS - 170 dB re 1 µPa2s | 2,781 | 3,148 | 7,385 | |
OCW | PTS - 203 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 188 dB re 1 µPa2s | N/E | 18 | 49 | |
Table 6.4: Summary of Injury Ranges due to the Maximum Peak Pressure over the Piling Sequence for Marine Mammals due to Impact Piling for Wind Turbine Foundations (“Maximum” Scenario) and OSP/Offshore Convertor Station Platform Foundations
Species/Group | Threshold (Unweighted Peak) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | ||
LF | PTS - 219 dB re 1 µPa (pk) | 109 | 83 | 134 |
TTS - 213 dB re 1 µPa (pk) | 180 | 138 | 222 | |
HF | PTS - 230 dB re 1 µPa (pk) | 43 | 33 | 53 |
TTS - 224 dB re 1 µPa (pk) | 71 | 55 | 88 | |
VHF | PTS - 202 dB re 1 µPa (pk) | 449 | 346 | 554 |
TTS - 196 dB re 1 µPa (pk) | 741 | 568 | 920 | |
PCW | PTS - 218 dB re 1 µPa (pk) | 118 | 91 | 146 |
TTS - 212 dB re 1 µPa (pk) | 195 | 150 | 241 | |
OCW | PTS - 232 dB re 1 µPa (pk) | 37 | 28 | 45 |
TTS - 226 dB re 1 µPa (pk) | 60 | 46 | 75 | |
Table 6.5: Summary of Injury Ranges due to the Maximum Peak Pressure Over the Piling Sequence for Marine Mammals due to Impact Piling for Wind Turbine Foundations (“Realistic” Scenario)
Species/Group | Threshold (Unweighted Peak) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | ||
LF | PTS - 219 dB re 1 µPa (pk) | 94 | 72 | 116 |
TTS - 213 dB re 1 µPa (pk) | 155 | 119 | 191 | |
HF | PTS - 230 dB re 1 µPa (pk) | 37 | 29 | 46 |
TTS - 224 dB re 1 µPa (pk) | 61 | 47 | 76 | |
VHF | PTS - 202 dB re 1 µPa (pk) | 388 | 298 | 478 |
TTS - 196 dB re 1 µPa (pk) | 638 | 490 | 788 | |
PCW | PTS - 218 dB re 1 µPa (pk) | 102 | 78 | 126 |
TTS - 212 dB re 1 µPa (pk) | 168 | 129 | 208 | |
OCW | PTS - 232 dB re 1 µPa (pk) | 31 | 24 | 39 |
TTS - 226 dB re 1 µPa (pk) | 52 | 40 | 64 | |
Table 6.6: Injury Ranges for Fish due to Impact Pile Driving for the “Maximum” Pile Driving for Wind Turbine Foundations for the Three Energy Conversion Factors Assessed – “Maximum” Scenario Includes Piling up to 4,000 kJ (N/E Is Threshold not Exceeded)
Hearing Group | Response | Threshold (SEL, dB re 1 µPa2s) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) – [basking shark ranges shown in square brackets]. | Mortality | 219 | N/E | N/E | N/E |
Recoverable injury | 216 | N/E | N/E | N/E | |
TTS | 186 | 5,852 [2,235] | 4,161 [2,219] | 7,442 [4,829] | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 210 | N/E | 19 | 39 |
Recoverable injury | 203 | 25 | 67 | 150 | |
TTS | 186 | 5,852 | 4,161 | 7,442 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | N/E | 33 | 66 |
Recoverable injury | 203 | 25 | 67 | 150 | |
TTS | 186 | 5,852 | 4,161 | 7,442 | |
Sea turtles | Mortality | 210 | N/E | 19 | 39 |
Fish eggs and larvae (static) | Mortality | 210 | 677 | 495 | 718 |
Hearing Group | Response | Threshold (SEL, dB re 1 µPa2s) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) – [basking shark ranges shown in square brackets]. | Mortality | 219 | N/E | N/E | N/E |
Recoverable injury | 216 | N/E | N/E | N/E | |
TTS | 186 | 4,367 [1,298] | 3,183 [1,609] | 5,938 [3,709] | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 210 | N/E | N/E | 31 |
Recoverable injury | 203 | 20 | 53 | 114 | |
TTS | 186 | 4,367 | 3,183 | 5,938 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | N/E | 26 | 53 |
Recoverable injury | 203 | 20 | 53 | 114 | |
TTS | 186 | 4,367 | 3,183 | 5,938 | |
Sea turtles | Mortality | 210 | N/E | N/E | 31 |
Fish eggs and larvae (static) | Mortality | 210 | 542 | 400 | 579 |
Table 6.8: Injury Ranges for Fish due to Impact Pile Driving for the Pile Driving for OSP/Offshore Convertor Station Platform Foundations for the Three Energy Conversion Factors Assessed –OSP/Offshore Convertor Station Platform Scenario Includes Piling up to 4,000 kJ (N/E Is Threshold not Exceeded)
Hearing Group | Response | Threshold (SEL, dB re 1 µPa2s) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) – [basking shark ranges shown in square brackets]. | Mortality | 219 | N/E | N/E | N/E |
Recoverable injury | 216 | N/E | N/E | N/E | |
TTS | 186 | 5,363 [2,058] | 3,943 [2,165] | 7,058 [4,679] | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 210 | N/E | 19 | 39 |
Recoverable injury | 203 | 25 | 67 | 149 | |
TTS | 186 | 5,363 | 3,943 | 7,058 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | N/E | 33 | 66 |
Recoverable injury | 203 | 25 | 67 | 149 | |
TTS | 186 | 5,363 | 3,943 | 7,058 | |
Sea turtles | Mortality | 210 | N/E | 19 | 39 |
Fish eggs and larvae (static) | Mortality | 210 | 592 | 439 | 638 |
Table 6.9: Summary of Injury Ranges due to the Maximum Peak Pressure Over the Piling Sequence for Fish due to Impact Piling for Wind Turbine Foundations (“Maximum” Scenario) and OSP/Offshore Convertor Station Platform Foundations
Hearing Group | Response | Threshold (SPLpk, dB re 1 µPa) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) | Mortality | 213 | 180 | 138 | 222 |
Recoverable injury | 213 | 180 | 138 | 222 | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 207 | 297 | 228 | 366 |
Recoverable injury | 207 | 297 | 228 | 366 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | 297 | 228 | 366 |
Recoverable injury | 207 | 297 | 228 | 366 | |
Sea turtles | Mortality | 207 | 297 | 228 | 366 |
Fish eggs and larvae | Mortality | 207 | 297 | 228 | 366 |
Table 6.10: Summary of Injury Ranges due to the Maximum Peak Pressure Over the Piling Sequence for Fish due to Impact Piling for Wind Turbine Foundations (“Realistic” Scenario)
Hearing Group | Response | Threshold (SPLpk, dB re 1 µPa) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) | Mortality | 213 | 155 | 119 | 191 |
Recoverable injury | 213 | 155 | 119 | 191 | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 207 | 255 | 196 | 315 |
Recoverable injury | 207 | 255 | 196 | 315 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | 255 | 196 | 315 |
Recoverable injury | 207 | 255 | 196 | 315 | |
Sea turtles | Mortality | 207 | 255 | 196 | 315 |
Fish eggs and larvae | Mortality | 207 | 255 | 196 | 315 |
Table 6.11: Injury Ranges for Marine Mammals due to Concurrent Impact Pile Driving at Two Locations for the “Maximum” Pile Driving for Wind Turbine Foundations for the Three Energy Conversion Factors Assessed – “Maximum” Scenario includes Piling up to 4,000 kJ (N/E Is Threshold not Exceeded)
Species/Group | Threshold (Weighted SEL) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10%-1% | ||
LF | PTS - 183 dB re 1 µPa2s | 1,305 | 2,319 | 5,830 |
TTS - 168 dB re 1 µPa2s | 54,550 | 42,931 | 62,172 | |
HF | PTS - 185 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 170 dB re 1 µPa2s | 18 | 35 | 84 | |
VHF | PTS - 155 dB re 1 µPa2s | 201 | 439 | 1,415 |
TTS - 140 dB re 1 µPa2s | 16,298 | 13,300 | 20,581 | |
PCW | PTS - 185 dB re 1 µPa2s | 25 | 53 | 150 |
TTS - 170 dB re 1 µPa2s | 8,490 | 6,731 | 13,476 | |
OCW | PTS - 203 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 188 dB re 1 µPa2s | N/E | 20 | 58 | |
Table 6.12: Injury Ranges for Marine Mammals due to Concurrent Impact Pile Driving at Two Locations for the “Realistic” Pile Driving for Wind Turbine Foundations for the Three Energy Conversion Factors Assessed – “Realistic” Scenario Includes Piling up to 3,000 kJ (N/E Is Threshold not Exceeded)
Species/Group | Threshold (Weighted SEL) | Range (m) | ||
|---|---|---|---|---|
1% | 4% - 0.5% | 10%-1% | ||
LF | PTS - 183 dB re 1 µPa2s | 675 | 1,556 | 4,439 |
TTS - 168 dB re 1 µPa2s | 45,893 | 35,991 | 53,519 | |
HF | PTS - 185 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 170 dB re 1 µPa2s | 13 | 27 | 64 | |
VHF | PTS - 155 dB re 1 µPa2s | 150 | 307 | 984 |
TTS - 140 dB re 1 µPa2s | 13,259 | 10,997 | 17,536 | |
PCW | PTS - 185 dB re 1 µPa2s | 18 | 38 | 106 |
TTS - 170 dB re 1 µPa2s | 5,713 | 4,966 | 10,523 | |
OCW | PTS - 203 dB re 1 µPa2s | N/E | N/E | N/E |
TTS - 188 dB re 1 µPa2s | N/E | 14 | 41 | |
Table 6.13: Injury Ranges for Fish due to Concurrent Impact Pile Driving at Two Locations for the “Maximum” Pile Driving for Wind Turbine Foundations for the Three Energy Conversion Factors Assessed – “Maximum” Scenario Includes Piling up to 4,000 kJ (N/E Is Threshold not Exceeded)
Hearing Group | Response | Threshold (SEL, dB re 1 µPa2s) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) – [basking shark ranges shown in square brackets]. | Mortality | 219 | N/E | N/E | N/E |
Recoverable injury | 216 | N/E | N/E | N/E | |
TTS | 186 | 9,912 [5,441] | 7,106 [4,342] | 11,660 [8,264] | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 210 | N/E | 21 | 44 |
Recoverable injury | 203 | 46 | 89 | 274 | |
TTS | 186 | 9,912 | 7,106 | 11,660 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | 20 | 37 | 86 |
Recoverable injury | 203 | 46 | 89 | 274 | |
TTS | 186 | 9,912 | 7,106 | 11,660 | |
Sea turtles | Mortality | 210 | N/E | 21 | 44 |
Fish eggs and larvae (static) | Mortality | 210 | 978 | 708 | 1,038 |
Table 6.14: Injury Ranges for Fish Due To Concurrent Impact Pile Driving at Two Locations for the “Realistic” Pile Driving for Wind Turbine Foundations for the Three Energy Conversion Factors Assessed – “Realistic” Scenario Includes Piling up to 3,000 kJ (N/E Is Threshold not Exceeded)
Hearing Group | Response | Threshold (SEL, dB re 1 µPa2s) | Range (m) | ||
|---|---|---|---|---|---|
1% | 4% - 0.5% | 10% - 1% | |||
Group 1 Fish: No swim bladder (particle motion detection) – [basking shark ranges shown in square brackets]. | Mortality | 219 | N/E | N/E | N/E |
Recoverable injury | 216 | N/E | N/E | N/E | |
TTS | 186 | 7,722 [3,837] | 5,612 [3,259] | 9,404 [6,523] | |
Group 2 Fish: Swim bladder not involved in hearing (particle motion detection) | Mortality | 210 | N/E | 16 | 34 |
Recoverable injury | 203 | 35 | 65 | 185 | |
TTS | 186 | 7,722 | 5,612 | 9,404 | |
Group 3 and 4 Fish: Swim bladder involved in hearing (primarily pressure detection) | Mortality | 207 | 16 | 29 | 64 |
Recoverable injury | 203 | 35 | 65 | 185 | |
TTS | 186 | 7,722 | 5,612 | 9,404 | |
Sea turtles | Mortality | 210 | N/E | 16 | 34 |
Fish eggs and larvae (static) | Mortality | 210 | 777 | 571 | 831 |