Figure 20 illustrates the distribution of Spiophanes bombyx across the area of interest. Spiophanes bombyx is a polychaete worm (Plate 2) which constructs tubes of sand grains; it
is common across the
southern North Sea and can often be found in high densities.
Spiophanes bombyx was found at 25 stations across the study site. These stations were spread over much of the cable corridor except for an area in the mid-section of the cable corridor and a section at the western end of the cable corridor. Twenty-two of the stations where S. bombyx was found supported fewer than 25 individuals of this species. None of the stations sampled supported more than 90 individuals of this species.
The amphipod crustacean Apherusa ovalipes is considered nationally
rare and has only
been recorded at a hand-full of sites around the UK, although it may be under-recorded.
Figure 21 outlines the station at which this species was recorded. Only one individual was recorded across the EAOW cable route sub-tidal area of search.
C.2.4 Relating the Multivariate Patterns within the Sediment Data to the Multivariate Patterns within the Faunal Data
A brief review of the information presented in Section C.1.2 and C.2.2 reveals the existence of a possible relationship
between
multivariate faunal groups and multivariate sediment groups sampled during the course of the East Anglia cable route area survey. In order to establish the robustness of this relationship, the faunal data were compared with the sediment data using the BIO-ENV and RELATE (see methods) multivariate statistical routines within PRIMER v6.
The RELATE routine provides a means of testing for correlations between two multivariate patterns, which in this case was a test for correlations between the distribution of biological communities and the distribution
of sediment types. The full
results of this test are presented in Appendix Table 10 which demonstrates that there was a significant relationship (Rho = 0.476, Significance Level = 0.1%) between the multivariate
patterns observed
sediment data and in the communities.
in the faunal
In order to ascertain which particle sizes correlated most strongly with the multivariate patterns observed within
the
faunal data the faunal and sediment data were tested using the BIO-ENV routine. The full results of this test are presented in Appendix Table 10 and reveal that the strongest correlation between the multivariate patterns in the sediment data and the faunal data occurred between sand (particle sizes 1 mm and 0.25-0.063mm) and silt (particle size <0.063mm). A combination of these sediment sizes together accounted for approximately almost 50% of the observed variation in faunal communities. Other factors that could influence the community composition are likely to include current speed, water depth and influence of the tidal regime.
