42. Where large numbers of similar sized fish and invertebrates were encountered, subsampling was carried out in an appropriate manner. Gobies, hermit crabs and small gurnards were identified to family level. Encrusting and colonial species were recorded on a presence and absence basis.
10.4.2.3 Statistical analysis 43. Multivariate statistical analysis of data from each survey campaign was conducted separately to characterise the benthic and epibenthic communities and investigate the relationships between the communities and the abiotic environment. The analyses used the Plymouth Marine Laboratories PRIMER v6 (Plymouth Routines in Multivariate Ecological Research) suite of programs. Further detail of these separate analyses is presented in Appendix 10.2, Appendix 10.3 and Appendix 10.4
44. Data were then were combined to form infaunal and epifaunal master data sets. All fish species were removed from the data as they are not considered part of the benthos and are considered within Chapter 11. The master data sets were also subjected to multivariate statistical analysis in order to characterise the benthic communities, the detail of which is presented in Appendix 10.6.
45.
Following a fourth- route transformation, both data sets were then subjected to hierarchical clustering to identify sample groupings based on the Bray Curtis index of similarity. A 20% similarity slice was used to separate infaunal communities and a 48% slice was used to separate epifaunal communities.
10.4.3 Impact Assessment Methodology 46.
The data sources summarised above in Table 10.4 were used to characterise the existing environment (section 10.5). Each impact, which has been identified using expert judgment and through consultation with Statutory Nature Conservation Bodies via the Evidence Plan Process is then assessed in terms of its significance using the following methods. The definitions for the sensitivity, value and magnitude of effect were also agreed in consultation during the Evidence Plan Process (see Appendix 10.1).
47.
The general approach to the assessment of the significance of each impact is detailed in Chapter 6 EIA Methodology and an explanation of how this is applied to benthic ecology within East Anglia THREE assessment is described below.
10.4.3.1 Sensitivity 48.
The sensitivity of the receptor for each impact is characterised as one of four levels, high, medium, low or negligible. The description of each level is given in Table 10.6, below.
Preliminary Environmental Information May 2014
East Anglia THREE Offshore Windfarm
Chapter 10 Benthic Ecology Page 26
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104