Gannet

In addition to the Matrix method, GPS tracking data of gannets from the Bass Rock colony 2010 - 2019 were analysed to contribute to understanding how the proposed Project may lead to displacement and barrier effects on this colony population. Data from breeding adults from Bass Rock were used to estimate behavioural states using Hidden Markov Models, and the proportion of time spent in each behavioural state and within and outwith the windfarm, split by sex. The analysis demonstrates the extensive spatial range of gannets from the colony and showed that males spent on average 10.5% less time transiting than females across all trips. When sex and behaviour were considered within the Development Array are only, males spent on average 38% more time foraging within the area than females.
Random resampling of the dataset using size of the Development Array area was used to explore the distribution of the data and whether there was evidence of it being used preferentially to other equivalently sized areas. The number of observations counted out of 863 samples of the dataset, showed that the proposed Development Array area had a higher count than 94% of the samples. However, this resampling does not account for proximity to colony or landmasses. Annex E details analysis of GPS tracks of gannet tracked from Bass rock in the Forth and Tay. It was found that of the 682 birds tracked, only 26.2% of those individuals entered the development area, and of those only 52.5% (94 birds) engaged in any foraging activities (see table 3.3). Figure 3.3 illustrates the locations of predicted foraging behaviour (as identified by hidden Markov modelling) and that due to the large home ranges (median 3,909 km2), most foraging activity occurs outside the development site.

Table 4.18: Potential gannet mortality following displacement from the Berwick Bank Development array in the breeding season. Estimates considered, in light of empirical evidence, to represent the most realistic scenarios are colour coded, with dark teal representing rates advised by the Scoping Opinion; dark teal and orange coloured hatching representing overlapping estimates from both the Scoping Opinion and Developer Approach.; and light teal representing uncertainty around these figures.

Gannet (Breeding season)	Mortality Level (% of displaced birds at risk of mortality)
Displacement Level (% of all birds on site)		0%	1%	2%	3%	4%	5%	10%	15%	20%	30%	50%	80%	100%
	0%	0	0	0	0	0	0	0	0	0	0	0	0	0
	10%	0	4	8	11	15	18	36	54	72	108	179	286	358
	20%	0	8	15	22	29	36	72	108	143	215	358	572	715
	30%	0	11	22	33	43	54	108	161	215	322	536	858	1072
	40%	0	15	29	43	58	72	143	215	286	429	715	1144	1429
	50%	0	18	36	54	72	90	179	268	358	536	893	1429	1786
	60%	0	22	43	65	86	108	215	322	429	643	1072	1715	2144
	70%	0	26	51	76	101	126	251	376	501	751	1251	2001	2501
	80%	0	29	58	86	115	143	286	429	572	858	1429	2287	2858
	90%	0	33	65	97	129	161	322	483	643	965	1608	2572	3215
	100%	0	36	72	108	143	179	358	536	715	1072	1786	2858	3572

Table 4.19: Potential gannet mortality following displacement from the Berwick Bank Development Array plus 2 km buffer in the breeding season. Estimates considered, in light of empirical evidence, to represent the most realistic scenarios are colour coded, with dark teal representing rates advised by the Scoping Opinion; dark teal and orange coloured hatching representing overlapping estimates from both the Scoping Opinion and Developer Approach.; and light teal representing uncertainty around these figures.

Gannet (Breeding season)	Mortality Level (% of displaced birds at risk of mortality)
Displacement Level (% of all birds on site)		0%	1%	2%	3%	4%	5%	10%	15%	20%	30%	50%	80%	100%
	0%	0	0	0	0	0	0	0	0	0	0	0	0	0
	10%	0	5	10	15	19	24	48	72	95	143	237	379	474
	20%	0	10	19	29	38	48	95	143	190	285	474	758	947
	30%	0	15	29	43	57	72	143	214	285	427	711	1137	1421
	40%	0	19	38	57	76	95	190	285	379	569	947	1516	1894
	50%	0	24	48	72	95	119	237	356	474	711	1184	1894	2368
	60%	0	29	57	86	114	143	285	427	569	853	1421	2273	2842
	70%	0	34	67	100	133	166	332	498	663	995	1658	2652	3315
	80%	0	38	76	114	152	190	379	569	758	1137	1894	3031	3788
	90%	0	43	86	128	171	214	427	640	853	1279	2131	3410	4262
	100%	0	48	95	143	190	237	474	711	947	1421	2368	3788	4735

Table 4.20: Potential gannet mortality following displacement from the Berwick Bank Development Array in the non-breeding season. Estimates considered, in light of empirical evidence, to represent the most realistic scenarios are colour coded, with dark teal representing rates advised by the Scoping Opinion; dark teal and orange coloured hatching representing overlapping estimates from both the Scoping Opinion and Developer Approach.; and light teal representing uncertainty around these figures.

Gannet (Non-breeding season)	Mortality Level (% of displaced birds at risk of mortality)
Displacement Level (% of all birds on site)		0%	1%	2%	3%	4%	5%	10%	15%	20%	30%	50%	80%	100%
	0%	0	0	0	0	0	0	0	0	0	0	0	0	0
	10%	0	2	3	4	5	6	11	16	21	31	51	82	102
	20%	0	3	5	7	9	11	21	31	41	62	102	164	204
	30%	0	4	7	10	13	16	31	46	62	92	153	245	306
	40%	0	5	9	13	17	21	41	62	82	123	204	327	408
	50%	0	6	11	16	21	26	51	77	102	153	255	408	510
	60%	0	7	13	19	25	31	62	92	123	184	306	490	612
	70%	0	8	15	22	29	36	72	107	143	214	357	571	714
	80%	0	9	17	25	33	41	82	123	164	245	408	653	816
	90%	0	10	19	28	37	46	92	138	184	276	459	734	918
	100%	0	11	21	31	41	51	102	153	204	306	510	816	1019

Table 4.21: Potential gannet mortality following displacement from the Berwick Bank Development array plus 2 km buffer in the spring migration (non-breeding) period. Estimates considered, in light of empirical evidence, to represent the most realistic scenarios are colour coded, with dark teal representing rates advised by the Scoping Opinion; dark teal and orange coloured hatching representing overlapping estimates from both the Scoping Opinion and Developer Approach; and light teal representing uncertainty around these figures.

Gannet (Spring migration)	Mortality Level (% of displaced birds at risk of mortality)
Displacement Level (% of all birds on site)		0%	1%	2%	3%	4%	5%	10%	15%	20%	30%	50%	80%	100%
	0%	0	0	0	0	0	0	0	0	0	0	0	0	0
	10%	0	0	1	1	1	1	3	4	5	8	13	22	27
	20%	0	1	1	2	2	3	5	8	11	16	27	43	54
	30%	0	1	2	2	3	4	8	12	16	24	40	65	81
	40%	0	1	2	3	4	5	11	16	22	32	54	86	108
	50%	0	1	3	4	5	7	13	20	27	40	67	108	134
	60%	0	2	3	5	6	8	16	24	32	48	81	129	161
	70%	0	2	4	6	8	9	19	28	38	56	94	151	188
	80%	0	2	4	6	9	11	22	32	43	65	108	172	215
	90%	0	2	5	7	10	12	24	36	48	73	121	194	242
	100%	0	3	5	8	11	13	27	40	54	81	134	215	269

Table 4.22: Potential gannet mortality following displacement from the Berwick Bank Development array plus 2 km buffer in the autumn migration (non-breeding) period. Estimates considered, in light of empirical evidence, to represent the most realistic scenarios are colour coded, with dark teal representing rates advised by the Scoping Opinion; dark teal and orange coloured hatching representing overlapping estimates from both the Scoping Opinion and Developer Approach; and light teal representing uncertainty around these figures.

Gannet (Autumn migration)	Mortality Level (% of displaced birds at risk of mortality)
Displacement Level (% of all birds on site)		0%	1%	2%	3%	4%	5%	10%	15%	20%	30%	50%	80%	100%
	0%	0	0	0	0	0	0	0	0	0	0	0	0	0
	10%	0	2	3	4	6	8	15	22	30	45	75	120	150
	20%	0	3	6	9	12	15	30	45	60	90	150	240	300
	30%	0	5	9	14	18	23	45	68	90	135	225	360	450
	40%	0	6	12	18	24	30	60	90	120	180	300	480	600
	50%	0	8	15	22	30	38	75	112	150	225	375	600	750
	60%	0	9	18	27	36	45	90	135	180	270	450	720	900
	70%	0	11	21	32	42	53	105	158	210	315	525	840	1050
	80%	0	12	24	36	48	60	120	180	240	360	600	960	1200
	90%	0	14	27	40	54	68	135	202	270	405	675	1080	1350
	100%	0	15	30	45	60	75	150	225	300	450	750	1200	1500

Previous part

Next part