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Publication - Progress report

Scottish Marine and Freshwater Science Volume 3 Number 5: SOTEAG Rocky Shore Monitoring Programme. TBT Contamination in Sullom Voe, Shetland. 2011 Dogwhelk Survey

Published
7 September 2012
Part of
Marine and fisheries
ISBN
9781782560401

This report provides the results and assessment of a survey carried out by Marine Scotland Science, Marine Laboratory, Aberdeen as part of a rocky shore monitoring programme undertaken by Aquatic Survey and Monitoring Limited, commissioned by the Shetland

View supporting documents Supporting documents

Table 1

Results of the 2011 survey of imposex in dogwhelks ( Nucella lapillus) in Sullom Voe and Yell Sound.

Site No Site Name Size Incidence of Occurrence % % RPSI VDSI No. Females No. Males
1 Easterwick 10‑15 0 0.00 0.00 5 5
15‑21 0 0.00 0.00 8 8
21‑26 18 0.00 0.18 11 7
26‑35 13 <0.01 0.25 8 2
Adults 14 <0.01 0.21 28 12
2 Burgo Taing Adults 21 <0.01 0.31 29 9
3 Billia Skerry 10‑15 50 0.01 0.67 6 4
15‑21 50 <0.01 0.57 6 1
21‑26 50 0.00 0.50 10 9
26‑35 60 <0.01 1.00 5 5
Adults 38 0.00 0.38 8 32
4 Scarf Stane Adults 67 0.00 0.67 3 7
5 East of Ollaberry 10‑15 36 0.05 0.45 11 3
15‑21 22 0.01 0.33 9 11
21‑26 7 0.00 0.07 14 5
26‑35 11 0.00 0.11 9 11
Adults 13 0.00 0.13 15 22
6 Grunn Taing Adults 67 <0.01 1.44 18 20
7 Tivaka Taing Adults 86 0.07 2.05 22 8
8 Noust of Burraland Adults 88 0.11 2.19 16 13
9 Mavis Grind 10‑15 100 0.46 1.33 3 1
15‑21 63 0.27 1.13 8 11
21‑26 57 <0.01 0.86 7 11
26‑35 50 0.01 0.90 10 9
Adults 87 0.17 2.4 15 23
10 Voxter Ness Adults 56 0.02 1.25 16 14
11 Northward Adults 86 0.31 2.73 22 13
12 Kames 10‑15 NA NA NA 0 0
15‑21 50 1.10 1.00 12 6
21‑26 70 0.23 1.70 10 10
26‑35 70 0.15 1.70 10 11
Adults 88 0.17 2.25 16 17
13 Skaw Taing Adults 70 0.07 1.6 20 20
14 Grunna Taing Adults 19 0.00 0.19 16 22
15 Orfassary Adults 22 <0.01 0.26 23 17
16 Samphrey/The Helliach Adults 7 <0.01 0.14 14 18
17 Uynarey Adults 23 <0.01 0.27 22 18
18 Little Roe Adults 46 <0.01 0.62 13 18
19 The Brough Adults 4 <0.01 0.08 24 15
22 Sweinna Stack Adults 6 0.00 0.06 17 20

Table 2

Summary of sampling carried out at sites 1-21 in Yell Sound and Sullom Voe for imposex development in toothed adult (*) and juvenile/sub-adult un-toothed adult (J) dogwhelks ( Nucella lapillus). Data taken from Bailey and Davies (1991), Harding et al. (1997), Minchin and Davies (2000), Gubbins et al (2005, 2008), Gubbins (2010) and the present survey.

Site 1987 1990 1991 1993 1995 1997 1999 2001 2004 2007 2009 2011
1 - - *J *J *J *J *J *J *J *J *J *J
2 - - * * * * * * * * * *
3 * * *J *J *J *J *J *J *J *J *J *J
4 * * * * * * * * * * * *
5 * *J *J *J *J *J *J *J *J *J *J *J
6 * *J * * * * * * * * * *
7 * * * * * * * * * * * *
8 * *J * * * * * * * * * *
9 * *J *J *J *J *J *J *J *J *J *J *J
10 * * * * * * * * * * * *
11 * *J * * * * * * * * * *
12 * *J * *J *J * *J *J *J *J *J *J
13 * * * * * * * * * * * *
14 - - * * * * * * * * * *
15 - - * * * * * * * * * *
16 - - * * * * * * * * * *
17 * * * * * * * * * * * *
18 * * * * * * * * * * * *
19 - - * * * * * * * - * *
20 - - * * * * * * * - * -
21 - - - - - *J * - - - - -
22 - - - - - - - - - - - *

Table 3

Data from surveys undertaken in 1987-2011. Numbers of toothed dogwhelk ( Nucella lapillus) individuals, percentage of females (%F) and percentage of sterile females (%FS) at each site.

- = No sampling; 0 = No sterile females found.

Site Site name 1987 1990 1991 1993 1995
Total %F %FS Total %F %FS Total %F %FS Total %F %FS Total %F %FS
1 Easterwick - - - - - - 48 60 0 40 45 0 41 56 0
2 Burgo Taing - - - - - - 40 73 0 40 43 0 41 20 0
3 Billia Skerry 41 54 0 41 56 0 40 50 0 40 43 0 40 48 0
4 Scarf Stane 40 63 0 41 46 0 38 45 0 40 40 19 40 43 0
5 East of Ollaberry 40 50 0 42 55 5 37 62 0 40 50 5 40 38 0
6 Grunn Taing 40 45 0 40 58 0 39 49 0 36 42 0 40 60 13
7 Tivaka Taing 40 45 22 39 41 71 39 44 29 38 42 19 40 30 25
8 Noust of Burraland/ Blanches Geo 40 35 21 28 32 33 38 30 91 40 33 15 40 43 59
9 Mavis Grind 40 48 21 43 49 55 29 28 63 26 15 50 40 43 35
10 Voxter Ness 30 57 65 40 75 77 39 26 60 40 25 60 40 35 57
11 Northward 40 40 44 36 28 30 40 28 91 41 32 77 40 25 40
12 The Kames 38 42 93 40 50 95 39 44 100 40 30 92 40 30 83
13 Skaw Taing 40 50 0 37 43 69 39 44 35 40 45 62 40 33 39
14 Moss Bank/ Grunna Taing - - - - - - 40 50 15 40 33 0 40 33 0
15 Orfasay - - - - - - 40 48 0 40 45 0 40 58 0
16 Samphrey/The Helliack - - - - - - 40 48 0 40 38 0 40 60 0
17 Uynarey 34 56 0 40 53 0 40 53 0 40 50 0 40 48 0
18 Little Roe 38 55 0 42 60 4 39 54 14 38 63 13 40 40 6
19 Brough - - - - - - 40 53 0 40 28 0 41 46 0
20 Norther Geo - - - - - - 40 43 0 40 23 0 38 63 0
21 Breiwick - - - - - - - - - - - - - - -

Table 3 (continued)

Site Site name 1997 1999 2001 2004 2007
Total %F %FS Total %F %FS Total %F %FS Total %F %FS Total %F %FS
1 Easterwick 40 40 0 40 45 0 40 60 0 39 56 0 40 65 0
2 Burgo Taing 40 63 0 40 40 0 40 50 0 40 63 0 40 50 0
3 Billia Skerry 40 58 0 40 50 0 40 43 0 40 35 0 39 38 0
4 Scarf Stane 40 53 0 40 45 6 39 44 59 38 37 7 40 58 0
5 East of Ollaberry 38 40 0 40 48 0 40 38 0 39 59 0 40 50 0
6 Grunn Taing 39 33 0 40 58 0 40 48 0 39 62 0 40 45 0
7 Tivaka Taing 39 54 10 40 65 10 40 48 0 39 72 0 40 48 0
8 Noust of Burraland/ Blanches Geo 40 43 24 40 55 9 40 40 25 39 46 6 40 68 11
9 Mavis Grind 40 28 27 40 20 13 40 30 42 39 46 22 40 23 11
10 Voxter Ness 40 38 7 40 25 0 40 53 5 40 53 10 40 23 0
11 Northward 40 35 7 40 35 0 40 23 0 40 43 18 37 35 8
12 The Kames 23 13 67 40 40 19 40 50 25 37 41 33 40 48 21
13 Skaw Taing 40 48 16 40 48 0 40 43 29 39 39 0 40 38 0
14 Moss Bank/ Grunna Taing 40 40 0 41 41 0 40 40 0 40 60 0 40 30 0
15 Orfasay 40 60 0 40 58 0 40 40 0 40 60 0 38 63 0
16 Samphrey/ The Helliack 40 38 0 40 45 0 40 35 0 40 38 0 40 50 0
17 Uynarey 40 45 0 40 40 0 40 45 0 39 46 0 40 43 0
18 Little Roe 40 38 0 40 45 0 39 41 6 42 57 0 40 45 0
19 Brough 40 35 0 40 45 0 40 48 0 39 46 0 - - -
20 Norther Geo 40 58 0 40 48 0 40 58 0 40 63 0 - - -
21 Breiwick 20 30 50 40 43 12 - - - - - - - - -

Table 3 (continued)

Site Site name 2009 2011
Total %F %FS Total %F %FS
1 Easterwick 40 55 0 40 70 0
2 Burgo Taing 40 65 0 38 76 0
3 Billia Skerry 40 58 0 40 20 0
4 Scarf Stane 40 50 0 10 30 0
5 East of Ollaberry 40 53 0 37 41 0
6 Grunn Taing 40 43 0 38 47 0
7 Tivaka Taing 38 58 0 30 73 0
8 Noust of Burraland/ Blanches Geo 39 49 0 29 55 0
9 Mavis Grind 40 40 0 38 39 0
10 Voxter Ness 39 31 0 30 53 0
11 Northward 39 56 0 35 63 0
12 The Kames 40 35 0 33 48 0
13 Skaw Taing 40 43 0 40 50 0
14 Moss Bank/ Grunna Taing 39 44 0 38 42 0
15 Orfasay 39 38 0 40 58 0
16 Samphrey/ The Helliack 40 45 0 32 44 0
17 Uynarey 40 53 0 40 55 0
18 Little Roe 40 48 0 31 42 0
19 Brough 38 58 0 39 62 0
20 Norther Geo 39 64 0 - - -
21 Breiwick - - - - - -
22 Sweinna Stack - - - 37 46 0

Table 4

RPSI and VDSI in adult dogwhelks ( Nucella lapillus) from populations in Sullom Voe and Yell Sound surveyed between 1987 and 2011.

J = sites at which juvenile/subadult surveys were carried out; - = No sampling.

RPSI

Site No Site name 1987 1990 1991 1993 1995 1997 1999 2001 2004 2007 2009 2011
1 J Easterwick - - 0.00 0.00 0.00 0.00 0.00 1.43 <0.01 <0.01 0.00 <0.01
2 Burgo Taing - - 3.37 <0.01 <0.01 0.02 <0.01 0.03 <0.01 <0.01 <0.01 <0.01
3 J Billia Skerry 0.64 1.45 0.24 0.06 0.02 0.02 0.05 0.16 0.27 <0.01 0.13 0.00
4 Scarf Stane 2.16 1.67 3.76 4.38 2.69 15.24 22.29 28.81 8.69 0.14 <0.01 0.00
5 J East of Ollaberry 2.41 7.51 3.53 0.31 0.23 0.94 0.39 0.09 0.12 <0.01 <0.01 0.00
6 Grunn Taing 12.71 13.52 15.00 4.92 7.33 7.18 4.69 6.20 4.62 0.95 0.00 <0.01
7 Tivaka Taing 58.85 34.19 23.72 14.06 20.34 19.90 21.52 14.21 10.55 3.45 0.54 0.07
8 Noust of Burraland 54.50 45.59 50.75 39.39 21.44 21.88 24.26 18.06 11.00 1.73 0.41 0.11
9 J Mavis Grind 40.91 30.24 30.15 23.19 11.63 24.11 21.33 28.61 20.33 4.29 1.08 0.17
10 Voxter Ness 58.54 39.59 41.32 32.38 27.65 28.05 24.27 27.65 12.63 2.69 0.01 0.02
11 Northward 34.03 30.54 42.57 31.37 26.70 36.70 40.26 30.71 14.73 7.86 0.31 0.31
12 J The Kames 56.78 69.44 54.93 37.49 31.32 73.12 35.65 34.03 16.99 0.90 0.26 0.17
13 Skaw Taing 42.46 32.34 45.00 18.26 20.59 27.16 20.02 23.61 14.43 2.59 0.26 0.07
14 Moss Bank/ Grunna Taing - - 5.04 0.18 0.37 0.76 0.64 0.50 0.07 0.01 0.67 0.00
15 Orfassary - - 0.54 0.05 0.09 0.01 0.59 0.02 <0.01 <0.01 <0.01 <0.01
16 Samphrey/ The Helliack - - 1.30 <0.01 0.01 0.02 <0.01 0.00 <0.01 <0.01 <0.01 <0.01
17 Uynarey 0.99 1.25 0.18 0.01 0.02 0.11 0.03 0.02 0.02 <0.01 <0.01 <0.01
18 Little Roe 13.46 9.69 18.89 14.10 5.30 12.00 5.81 8.91 3.76 1.62 0.03 <0.01
19 The Brough - - 0.63 <0.01 <0.01 0.00 <0.01 0.00 0.01 - 0.01 <0.01
20 Norther Geo - - 0.13 0.01 0.00 0.00 0.00 0.00 0.00 - 0.00 -
21 Breiwick - - - - - 38.89 33.51 - - - - -
22 Sweinna Stack - - - - - - - - - - - 0.00

Table 4 (Continued)

VDSI

SITE NO. SITE NAME 1987 1990 1991 1993 1995 1997 1999 2001 2004 2007 2009 2011
1 J Easterwick - - 0.26 0.05 0.04 0.06 0.33 0.17 0.36 0.15 0.46 0.21
2 Burgo Taing - - 1.72 1.13 1.00 0.92 1.125 0.25 0.28 0.50 0.58 0.31
3 J Billia Skerry 2.32 2.35 2.30 2.06 1.11 1.04 1.25 1.76 1.79 1.20 1.50 0.38
4 Scarf Stane 3.44 3.42 3.53 3.75 3.82 3.67 4.06 4.59 4.07 2.56 0.95 0.67
5 J East of Ollaberry 3.21 3.95 3.39 2.55 2.47 2.33 2.68 1.60 1.57 0.70 0.38 0.13
6 Grunn Taing 4.00 4.00 4.00 3.73 4.13 4.00 4.00 4.00 3.46 3.50 0.59 1.44
7 Tivaka Taing 4.22 4.93 4.41 4.19 4.25 4.09 4.00 4.00 4.00 3.58 2.64 2.05
8 Noust of Burraland 4.21 4.33 5.00 4.15 4.65 4.24 4.09 4.31 4.05 4.00 3.53 2.19
9 J Mavis Grind 4.26 4.64 4.75 4.50 4.35 4.27 4.125 4.42 4.25 4.11 3.67 2.4
10 Voxter Ness 4.71 4.83 4.80 4.60 4.57 4.07 4.00 4.05 4.10 3.78 1.30 1.25
11 Northward 4.44 4.87 5.18 4.77 4.40 4.07 4.07 4.33 4.18 4.08 3.14 2.73
12 J The Kames 5.27 5.33 5.59 5.08 5.17 4.67 4.19 4.25 4.33 3.89 3.00 2.25
13 Skaw Taing 4.00 4.69 4.41 4.61 4.31 4.16 4.00 4.29 4.00 3.33 2.77 1.60
14 Moss Bank/ Grunna Taing - - 4.05 1.77 2.46 2.13 2.65 1.88 1.47 1.08 3.24 0.19
15 Orfassary - - 2.74 1.78 1.04 0.88 1.65 0.81 1.12 0.83 0.40 0.26
16 Samphrey/ The Helliack - - 2.32 0.53 0.63 0.87 0.72 0.43 0.40 0.20 0.33 0.14
17 Uynarey 2.58 2.86 2.05 1.20 0.90 1.56 1.375 0.78 1.17 0.82 0.38 0.27
18 Little Roe 4.00 4.04 4.14 4.13 4.06 3.93 3.94 2.19 3.63 3.56 1.95 0.62
19 The Brough - - 2.57 1.09 1.16 0.43 0.83 0.61 0.89 - 0.38 0.08
20 Norther Geo - - 1.35 0.56 0.00 0.30 0.43 0.17 0.08 - 0.20 -
21 Breiwick - - - - - 4.50 4.10 - - - - -
22 Sweinna Stack - - - - - - - - - - - 0.06

Table 5

Oslo and Paris Commission biological effects assessment criteria for imposex in Nucella lapillus, based on VDSI ( OSPAR, 2004) and amended to show which classes exceed Background Assessment Criteria ( BAC) and Environmental Assessment Criteria ( EAC).

Assessment class Nucella VDSI Effects and impacts
A (< BAC) VDSI = <0.3 The level of imposex in the more sensitive gastropod species is close to zero (0 - ~30% of females have imposex) indicating exposure to TBT concentrations close to zero, which is the objective in the OSPAR strategy of hazardous substances.
B (> BAC < EAC) VDSI = 0.3 - <2.0 The level of imposex in the more sensitive gastropod species (~30 - ~100 % of the females have imposex) indicates exposure to TBT concentrations below the EAC derived for TBT. E.g. adverse effects in the more sensitive taxa of the ecosystem caused by long-term exposure to TBT are predicted to be unlikely to occur.
C (> EAC) VDSI = 2.0 - <4.0 The level of imposex in the more sensitive gastropod species indicates exposure to TBT concentrations higher than the EAC derived for TBT. E.g. there is a risk of adverse effects, such as reduced growth and recruitment, in the more sensitive taxa of the ecosystem caused by long-term exposure to TBT.
D (> EAC) VDSI = 4.0 - 5.0 The reproductive capacity in the populations of the more sensitive gastropod species, such as Nucella lapillus, is affected as a result of the presence of sterile females, but some reproductively capable females remain. E.g. there is evidence of adverse effects, which can be directly associated with the exposure to TBT.
E (> EAC) VDSI = > 5.0 Populations of the more sensitive gastropod species, such as Nucella lapillus, are unable to reproduce. The majority, if not all females within the population have been sterilized.
F (> EAC) VDSI = - The populations of the more sensitive gastropod species, such as Nucella lapillus and Ocinebrina aciculata, are absent/expired.

Table 6

Temporal changes in OSPAR imposex classes at sites in Sullom Voe and Yell Sound. See Table 5 for key to OSPAR classes (A: VDSI<0.3; E: VDSI>5.0).

Site 1987 1990 1991 1993 1995 1997 1999 2001 2004 2007 2009 2011
1 - - A A A A B A B A B A
2 - - B B B B B A A B B B
3 C C C C B B B B B B B B
4 C C C C C C D D D C B B
5 C C C C C C C B B B B A
6 D D D C D D D D C C B B
7 D D D D D D D D D C C C
8 D D D D D D D D D D C C
9 D D D D D D D D D D C C
10 D D D D D D D D D C B B
11 D D E D D D D D D D C C
12 E E E E E D D D D C C C
13 D D D D D D D D D C C B
14 - - D B C C C B B B C A
15 - - C B B B B B B B B A
16 - - C B B B B B B A B A
17 C C C B B B B B B B B A
18 D D D D D C C C C C B B
19 - - C B B B B B B - B A
20 - - B B A A B A A - A -
22 - - - - - - - - - - - A

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