Tunnel-valleys are prominent features of the southern North Sea, where they form actuate and linear seabed depressions with a limited sediment infill. In the outer Humber area, the valleys attain water depths up to 100 m and radiate outward from the mapped palaeo-ice margin of the Devensian (Weischelian) glaciations. The location and orientation of the valleys indicates that their origin is associated with the ice sheet, although the precise process of formation is uncertain. It is likely that the valleys were formed by either subglacial fluvial activity or ice-damn breakouts. Extensive areas of Sabellaria spinulosa reefs have been identified on the western flanks of the Silver Pit that extend down to the valley floor, representing a resource of significant conservation interest. The eastern flanks were found to support a diverse faunal assemblage with widespread hydroid and bryozoans turfs and abundant ascidians. The seabed of the Sole Pit is characterized by much sandier deposits than that of the Silver Pit, and it supports an abundant bivalve community, dominated by Abra alba. This bivalve assemblage also contains Coarcuta obliquata, which has only been recorded once before in the UK. A multivariate analysis of similarity (ANOSIM) test was used to investigate differences between the macrofauna associated with the tunnel-valleys and macrofauna recorded across the wider Humber study area. The ANOSIM test is analogous to a univariate analysis of variance (ANOVA) test based on permutations, or randomization, of the data, making minimal assumptions about the distribution of that data.