Has Loss of Accommodation Space in the Humber Estuary Led to Elevated Suspended Sediment Concentrations?

The role of anthropogenic modification of the Humber estuary (England, UK) is examined in the context of its exceptionally high suspended sediment concentrations (SSCs). Loss of accommodation space through land claim for agriculture over the past 1,000 years has led to the evolution of channel that may be described as a tidal canal. We explore some relevant analogues in order to determine whether any correlation exists among the degree of narrowing, the extent of tidal propagation, and the persistence of elevated SSCs. Several examples are shown of estuaries whose tidal range and SSC have been manipulated by anthropogenic changes to their geometry. It is postulated that this modern form has resulted in increased tidal propagation and that elevated sediment loads within the Humber Estuary have been influenced by a loss of accommodation space. We propose that should this association be substantiated then accommodation space should be regarded as a significant ‘ecosystem function’ in regulating suspended sediment concentrations and water quality. Our analysis highlights a suite of ecosystem services that include the regulation of tidal range as well as of SSC. It provides the basis for a broader approach to coastal management in which the role of accommodation space is given a higher profile from an engineering perspective. A wider suite of biochemical benefits may also arise in the aftermath of substantial realignments, emphasising the broader relationship between managed realignment, sediment availability and ecological functioning.