3.3. Minke Whale

3.3.1. Scenario MW-01a: Maximum Temporal Scenario (SPLpk)

  1. Results for the maximum temporal scenario, with numbers of potentially affected animals based upon the SPLpk metric for PTS, indicate a very small difference in the growth trajectory of minke whale between the unimpacted population and impacted population ( Figure 3.7   Open ▸ ). At all time points there was little difference in the mean size of the impacted and unimpacted populations, with a maximum difference of one individual (approximately 0.005% of the Celtic and Greater North Seas MU reference population) at various time points throughout the modelled simulations, including time point 7 and time point 26, corresponding to six years after the start of piling, and 18 years after the completion of piling ( Table 3.7   Open ▸ ), and both aligning with the six-year duration of Habitats Directive reporting periods.

Figure 3.7:
Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Temporal Scenario MW-01a, Based on the SPLpk Metric for PTS

Figure 3.7: Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Temporal Scenario MW-01a, Based on the SPLpk Metric for PTS

 

  1. At time point 13, which corresponds with six years after the end of the piling phase for wind turbine anchors, and twelve years after the start of the piling phase (aligning with the duration of one and two Habitats Directive reporting periods, respectively) there was no difference between the size of the impacted and unimpacted populations.

 

Table 3.7:
Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Temporal Scenario MW-01a, Based on the SPLpk Metric for PTS

Table 3.7: Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Temporal Scenario MW-01a, Based on the SPLpk Metric for PTS

 

  1. At time point 26, which represents the population at the end point of the iPCoD modelling, 25 years after the start of piling (and 18 years after the completion of the piling phase), this difference is one animal ( Table 3.7   Open ▸ ), corresponding to approximately 0.005% of the reference population. This suggests that there would not be a long term effect from piling at the Array upon the minke whale population within the Celtic and Greater North Seas MU.
  2. Both the median and mean counterfactual for scenario minke whale-01a remained at 1.0000 throughout the 26-year simulation, indicating no discernible difference in the ratio of the disturbed to un-disturbed populations and no potential for a long term population-level effect from this piling scenario upon minke whale.

3.3.2. ScenariO MW-01b: Maximum Temporal Scenario (SELcum)

  1. Results for the maximum temporal scenario, with numbers of potentially affected animals based upon the SELcum metric for PTS, indicate a small difference in the growth trajectory of minke whale between the unimpacted population and impacted population ( Figure 3.8   Open ▸ ). This difference is larger when compared to results from scenario MW-01a, based upon the SPLpk metric. At all time points there was little difference in the mean size of the impacted and unimpacted populations relative to the reference population, with a maximum difference of 55 individuals (approximately 0.27% of the Celtic and Greater North Seas MU reference population) from time point 21 through to the end of modelled simulations. At time point 7, corresponding to six years after the start of piling and aligning with the six-year duration of Habitats Directive reporting periods, this difference was 16 individuals ( Table 3.8   Open ▸ ).

Figure 3.8:
Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Temporal Scenario MW-01b, Based on the SELcum Metric for PTS

Figure 3.8: Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Temporal Scenario MW-01b, Based on the SELcum Metric for PTS

 

  1. At time point 13, which corresponds with six years after the end of the piling phase for wind turbine anchors, and twelve years after the start of the piling phase (aligning with the duration of one and two Habitats Directive reporting periods, respectively) there was a difference between the size of the impacted and unimpacted populations of 40 individuals.

 

Table 3.8:
Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Temporal Scenario MW-01b, Based on the SELcum Metric for PTS

Table 3.8: Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Temporal Scenario MW-01b, Based on the SELcum Metric for PTS

 

  1. At time point 26, which represents the population at the end point of the iPCoD modelling, 25 years after the start of piling (and 18 years after the completion of the piling phase), this difference is 55 animals ( Table 3.8   Open ▸ ), corresponding to approximately 0.27% of the reference population. This suggests that there would not be a long term effect from piling at the Array upon the minke whale population within the Celtic and Greater North Seas MU.
  2. Both the median and mean counterfactual for scenario MW-01b started at 1.00 from the start of the 26-year simulation, decreasing to approximately 0.997, indicating minimal discernible difference in the ratio of the disturbed to un-disturbed populations, and no potential for a long term population-level effect from this piling scenario upon minke whale.

3.3.3. Scenario MW-02a: Maximum Spatial Scenario (SPLpk)

  1. Results for the maximum spatial scenario, with numbers of potentially affected animals based upon the SPLpk metric for PTS, indicated a very small difference in the growth trajectory of minke whale between the unimpacted population and impacted population ( Figure 3.5   Open ▸ ). At all time points there was little difference in the mean size of the impacted and unimpacted populations, with a maximum difference of one individual (approximately 0.005% of the Celtic and Greater North Seas MU reference population) at various time points in the simulation ( Table 3.5   Open ▸ ).

Figure 3.9:
Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Spatial Scenario MW-02, Based on the SPLpk Metric for PTS

Figure 3.9: Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Spatial Scenario MW-02, Based on the SPLpk Metric for PTS

 

  1. At time point 7, which represents the end of the concurrent piling phase, and corresponds to the six-year reporting period formerly required under the Habitats Directive, the impacted population was predicted to be the same size as the unimpacted population.
  2. At time point 13, which corresponds with six years after the end of the concurrent portion of the piling phase, and twelve years after the start of the piling phase (aligning with the duration of one and two Habitats Directive reporting periods, respectively) the difference between the impacted and unimpacted populations was one animal, approximately 0.005% of the reference population.

 

Table 3.9:
Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Spatial Scenario MW-02b, Based on the SPLpk Metric for PTS

Table 3.9: Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Spatial Scenario MW-02b, Based on the SPLpk Metric for PTS

 

  1. At time point 26, which represents the population at the end point of the iPCoD modelling, 25 years after the start of piling (and 18 years after the completion of the piling phase), this difference is also one animal, corresponding to approximately 0.005% of the reference population ( Table 3.5   Open ▸ ). This indicates that there would not be a long term effect from piling at the Array upon the minke whale population within the Celtic and Greater North Seas MU.
  2. Both the median and mean counterfactual for scenario MW-01 remained at 1.0000 throughout the 26-year simulation, indicating no discernible difference in the ratio of the disturbed to un-disturbed populations and no potential for a long term population-level effect from this piling scenario upon minke whale.

3.3.4. Scenario MW-02b: Maximum Spatial Scenario (SELcum)

  1. Results for the maximum spatial scenario, with numbers of potentially affected animals based upon the SELcum metric for PTS, indicated a very small difference in the growth trajectory of minke whale between the unimpacted population and impacted population ( Figure 3.10   Open ▸ ). At all time points there was some difference in the mean size of the impacted and unimpacted populations, with a maximum difference of 173 individuals (approximately 0.86% of the Celtic and Greater North Seas MU reference population) at various time points in the simulation ( Table 3.10   Open ▸ ).

Figure 3.10:
Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Spatial Scenario MW-02b, Based on the SELcum Metric for PTS

Figure 3.10: Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for the Maximum Spatial Scenario MW-02b, Based on the SELcum Metric for PTS

 

  1. At time point 7, which represents the end of the concurrent piling phase, and corresponds to the six-year reporting period formerly required under the Habitats Directive, the impacted population was predicted to be the 53 individuals (0.26%) smaller than the unimpacted population.
  2. At time point 13, which corresponds with six years after the end of the concurrent portion of the piling phase, and twelve years after the start of the piling phase (aligning with the duration of one and two Habitats Directive reporting periods, respectively) the difference between the impacted and unimpacted populations was 133 individuals, approximately 0.66% of the reference population.

 

Table 3.10:
Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Spatial Scenario MW-02b, Based on the SELcum Metric for PTS

Table 3.10: Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for the Maximum Spatial Scenario MW-02b, Based on the SELcum Metric for PTS

 

  1. At time point 26, which represents the population at the end point of the iPCoD modelling, 25 years after the start of piling (and 18 years after the completion of the piling phase), this difference is 173 individuals, corresponding to approximately 0.86% of the reference population ( Table 3.10   Open ▸ ). This indicates that there would not be a long term effect from piling at the Array upon the minke whale population within the Celtic and Greater North Seas MU.
  2. Both the median and mean counterfactual for scenario MW-02b began at 1.0000 and decreased across the 26-year simulation to 0.9924 (median) and 0.9914 (mean). This small change indicates minimal discernible difference in the ratio of the disturbed to un-disturbed populations and no potential for a long term population-level effect from this piling scenario upon minke whale.

3.3.5. Scenario MW-C1: Cumulative Scenario

  1. For scenario MW-C1, in which a total of 306 days of piling were modelled at the Array alongside a total of 273 piling days across Tier 1 cumulative projects (112 days at Berwick Bank, and 161 days at Hornsea Three) these results indicate no difference in the simulated trajectories of minke whale between the unimpacted population and impacted population ( Figure 3.11   Open ▸ ). This corresponds to no difference in the size of the impacted population at time point 26, compared to the un-impacted population ( Table 3.11   Open ▸ ).
  2. At time point 5, which corresponds to the third year of piling at the Array, the first year after the end of piling at Berwick Bank, and three years after the end of piling at Hornsea Three, the difference between impacted and un-impacted populations is one animal (0.005% of the reference population). When compared to the equivalent time point from scenario MW-01 (i.e. three years into the maximum temporal scenario for the Array alone: section 3.3.1), this is a difference between scenarios of one animal.

Figure 3.11:
Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for Cumulative Scenario MW-C1

Figure 3.11: Simulated Minke Whale Population Trajectories in an Unimpacted Versus Impacted Population, for Cumulative Scenario MW-C1

 

Table 3.11:
Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for Cumulative Scenario MW-C1

Table 3.11: Modelled Estimates for the Unimpacted and Impacted Minke Whale Populations and Counterfactuals of Population Size for Cumulative Scenario MW-C1

 

  1. Both the median and mean counterfactual of population size for cumulative scenario MW-C1 was 1.0000 throughout the 26-year simulation. Therefore, given that the differences in disturbed to undisturbed populations equates to a ratio of 1 there is not considered to be a potential for a long term population-level effect from this cumulative piling scenario upon minke whale within the Celtic and Greater North Seas MU.