3.8 Guillemot - Forth Islands SPA

Figure 3.25:
Projections of population sizes over a 50-year time-frame. Each plot represents a different impact scenario in terms of additional adult mortalities (starting at 0 i.e. unimpacted). Blue envelopes bound the central 95% of simulations, the dark central line the median.

Figure 3.25:  Projections of population sizes over a 50-year time-frame. Each plot represents a different impact scenario in terms of additional adult mortalities (starting at 0 i.e. unimpacted). Blue envelopes bound the central 95% of simulations, the dark central line the median.


Figure 3.26:
Ratio of impacted and unimpacted growth rates under a range of impact scenarios (additional adult mortalities – x-axis) i.e. 0.9 means a 10% decrease in the growth rate under the impact scenario. Figures are based on paired simulations for the impacted and unimpacted populations i.e. based on the same sampled population parameters. The bold lines represent the 50th percentile (median), dashed lines give the central 95% of simulated values (2.5% and 97.5% reference points).

Figure 3.26:  Ratio of impacted and unimpacted growth rates under a range of impact scenarios (additional adult mortalities – x-axis) i.e. 0.9 means a 10% decrease in the growth rate under the impact scenario. Figures are based on paired simulations for the impacted and unimpacted populations i.e. based on the same sampled population parameters. The bold lines represent the 50th percentile (median), dashed lines give the central 95% of simulated values (2.5% and 97.5% reference points).

Figure 3.27:
The ratio of the median impacted and median unimpacted population sizes from the simulations over a range of impact scenarios (additional adult deaths - x-axis) i.e. 0.5 means the median impacted population size is one-half the median unimpacted population size. Figures are based on paired simulations for the impacted and unimpacted populations i.e. based on the same sampled population parameters. The bold lines represent the 50th percentile (median), dashed lines give the central 95% of simulated values (2.5% and 97.5% reference points).

Figure 3.27:  The ratio of the median impacted and median unimpacted population sizes from the simulations over a range of impact scenarios (additional adult deaths - x-axis) i.e. 0.5 means the median impacted population size is one-half the median unimpacted population size. Figures are based on paired simulations for the impacted and unimpacted populations i.e. based on the same sampled population parameters. The bold lines represent the 50th percentile (median), dashed lines give the central 95% of simulated values (2.5% and 97.5% reference points).

Figure 3.28:
The median of the impacted population size as a centile of the unimpacted population size, under a range of impact scenarios (incremental additional adult deaths – x-axis). For example, 30 means the median (50th percentile) of the impacted projections sits at the 30th percentile of the unimpacted projections. Individual lines represent years post-construction (35 and 50 years).

Figure 3.28:  The median of the impacted population size as a centile of the unimpacted population size, under a range of impact scenarios (incremental additional adult deaths – x-axis). For example, 30 means the median (50th percentile) of the impacted projections sits at the 30th percentile of the unimpacted projections. Individual lines represent years post-construction (35 and 50 years).


Table 3.37: Growth rates of simulated populations under different impact scenarios for the 35 and 50 year post-construction projections. Reference points are 2.5%, 50% (median) and 97.5% of the distribution of simulated growth rates.

Projection year

Additional adult mortalities

Median growth rates

2.5 percentile of simulated growth rates

97.5 percentile of simulated growth rates

Median counterfactual of population size

Median counterfactual of growth rates

Centile of unimpacted matching 50th centile of unimpacted

2062

0

1.025

1.011

1.038

 

 

 

2062

50

1.023

1.009

1.036

0.943

0.998

41.4

2062

100

1.021

1.007

1.034

0.889

0.997

32.8

2062

150

1.020

1.006

1.033

0.838

0.995

25.3

2062

200

1.018

1.004

1.031

0.789

0.993

18.8

2062

250

1.016

1.002

1.029

0.744

0.992

13.4

2062

300

1.015

1.001

1.028

0.701

0.990

9.3

2062

350

1.013

0.999

1.026

0.661

0.989

6.1

2062

400

1.011

0.997

1.024

0.622

0.987

4.0

2062

450

1.010

0.996

1.023

0.586

0.985

2.3

2062

500

1.008

0.994

1.021

0.552

0.984

1.3

2062

550

1.006

0.992

1.019

0.520

0.982

0.7

2062

600

1.005

0.991

1.017

0.490

0.980

0.3

2062

650

1.003

0.989

1.016

0.461

0.979

0.1

2062

700

1.001

0.987

1.014

0.434

0.977

0.1

2077

0

1.025

1.013

1.035

 

 

 

2077

50

1.023

1.012

1.034

0.920

0.998

39.3

2077

100

1.021

1.010

1.032

0.846

0.997

29.0

2077

150

1.020

1.008

1.030

0.778

0.995

20.5

2077

200

1.018

1.007

1.029

0.715

0.993

13.6

2077

250

1.016

1.005

1.027

0.657

0.992

8.6

2077

300

1.015

1.003

1.025

0.604

0.990

5.4

2077

350

1.013

1.002

1.024

0.555

0.989

3.1

2077

400

1.011

1.000

1.022

0.510

0.987

1.4

2077

450

1.010

0.998

1.020

0.469

0.985

0.7

2077

500

1.008

0.997

1.019

0.430

0.984

0.3

2077

550

1.006

0.995

1.017

0.395

0.982

0.2

2077

600

1.005

0.993

1.015

0.363

0.980

0.1

2077

650

1.003

0.992

1.014

0.333

0.979

0.0

2077

700

1.001

0.990

1.012

0.306

0.977

0.0


Table 3.38: Relevant PVA metrics from models with impact scenarios for specific additional mortalities. Tabulated adult deaths account for the indicated sabbatical rate. Med. popn size = Median population size, Med. popn size (2062) 2.5/97.5% = are the central 95% of simulated population sizes.

Scenario

Sabb. Rate

Add. adult deaths

Add. immat. deaths

Med. popn size (2062)

Med. popn size (2062) 2.5%

Med. popn size (2062) 97.5%

Baseline

0.07

0.000

0.00

94669.2

56296.1

155125.7

North Sea Consented developer approach

0.07

82.817

80.12

85775.6

50936.8

140669.3

North Sea Consented Scoping Approach a

0.07

200.880

200.60

74243.3

44005.9

121879.1

North Sea Consented Scoping Approach b

0.07

398.910

392.06

58558.6

34572.7

96176.7

(1) Project Alone: developer approach

0.07

37.417

36.62

90521.5

53798.7

148392.6

(2) Project Alone: Scoping approach a

0.07

91.576

91.20

84773.6

50333.2

139040.0

(2) Project Alone: Scoping approach b

0.07

180.510

178.26

76174.3

45167.3

125044.8

 

Table 3.39: Relevant PVA metrics from models with impact scenarios for specific additional mortalities. Tabulated adult deaths account for the indicated sabbatical rate. Med. popn size = Median population size, Med. popn size (2077) 2.5/97.5% = are the central 95% of simulated population sizes.

Scenario

Sabb. Rate

Add. adult deaths

Add. immat. deaths

Med. popn size (2077)

Med. popn size (2077) 2.5%

Med. popn size (2077) 97.5%

Baseline

0.07

0.000

0.00

136427.1

73734.0

242852.2

North Sea Consented developer approach

0.07

82.817

80.12

118627.3

63993.4

211129.0

North Sea Consented Scoping Approach a

0.07

200.880

200.60

96642.1

52015.9

172026.3

North Sea Consented Scoping Approach b

0.07

398.910

392.06

68929.1

36969.5

122732.8

(1) Project Alone: developer approach

0.07

37.417

36.62

128046.7

69143.5

227910.5

(2) Project Alone: Scoping approach a

0.07

91.576

91.20

116665.8

62918.3

207625.9

(2) Project Alone: Scoping approach b

0.07

180.510

178.26

100240.3

53971.7

178428.5


Table 3.40: Relevant PVA metrics from models with impact scenarios for specific additional mortalities. Tabulated adult deaths account for the indicated sabbatical rate. Ann. med. GR = Annual median growth rate, Ann. med. GR lower/upper CI are the 95% confidence bounds.

Scenario

Sabb. Rate

Add. adult deaths

Add. immat. deaths

Ann. med. GR (2062)

Ann. med. GR (2062) lower CI

Ann. med. GR (2062) upper CI

Ann. med. GR (2077)

Ann. med. GR (2077) lower CI

Ann. med. GR (2077) upper CI

Baseline

0.07

0.000

0.00

1.025

1.011

1.038

1.025

1.013

1.035

North Sea Consented developer approach

0.07

82.817

80.12

1.022

1.008

1.035

1.022

1.011

1.033

North Sea Consented Scoping Approach a

0.07

200.880

200.60

1.018

1.004

1.031

1.018

1.007

1.028

North Sea Consented Scoping Approach b

0.07

398.910

392.06

1.011

0.997

1.024

1.011

1.000

1.022

(1) Project Alone: developer approach

0.07

37.417

36.62

1.024

1.010

1.036

1.024

1.012

1.034

(2) Project Alone: Scoping approach a

0.07

91.576

91.20

1.022

1.008

1.034

1.022

1.010

1.032

(2) Project Alone: Scoping approach b

0.07

180.510

178.26

1.019

1.005

1.031

1.019

1.007

1.029


Table 3.41: Relevant PVA metrics from models with impact scenarios for specific additional mortalities. Tabulated adult deaths account for the indicated sabbatical rate. Med. cnterfact. popn size = Median counterfactual of population size, Med. cnterfact. GR = Median counterfactual of growth rates, Cent. unimp. match 50th cent. unimp. = Centile of unimpacted matching 50th centile of unimpacted.

Scenario

Sabb. Rate

Add. adult deaths

Add. immat. deaths

Med. cnterfact. popn size (2062)

Med. cnterfact. popn size (2077)

Med. cnterfact. GR (2062)

Med. cnterfact GR (2077)

North Sea Consented developer approach

0.07

82.817

80.12

0.906

0.869

0.997

0.997

North Sea Consented Scoping Approach a

0.07

200.880

200.60

0.784

0.708

0.993

0.993

North Sea Consented Scoping Approach b

0.07

398.910

392.06

0.618

0.505

0.987

0.987

(1) Project Alone: developer approach

0.07

37.417

36.62

0.956

0.938

0.999

0.999

(2) Project Alone: Scoping approach a

0.07

91.576

91.20

0.895

0.855

0.997

0.997

(2) Project Alone: Scoping approach b

0.07

180.510

178.26

0.804

0.734

0.994

0.994