Challenges of restoring polluted industrialized muddy NW European estuaries
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| Keywords |
Marine/Coastal; Brackish water; Fresh water |
| Author keywords |
Estuaries; Fluid Mud; Nautical depth; In situ bio-remediation; Tidal asymmetry; Intertidal zone; Restoration; Deep-drafted vessels |
| Abstract |
Estuaries are susceptible to man-induced changes. Among others, two intertidal and two subtidal alterations can, in circumstances, be regarded as exploitation, not “management.” Coupled intertidal and unprecedented channel changes to facilitate modern ship movements have greatly diminished bed friction. Tide range and flood velocity increases have caused pumping and trapping of mud from seawards. Modeling reveals that the Scheldt, Weser, Ems, and Loire estuaries have all shifted in various degrees to new unnatural, stable hyper-turbid regimes. Early faltering attempts at restoration are outlined.Expected variable sea-level rise, peaking in the north Irish Sea and waters fronting the Weser, Ems, and Scheldt have major coastal protection implications. High costs from this will be exacerbated by estuary restoration needs.Looking positively, more sustainable navigation will derive from better “waterside management” for ports. Vessels can sail through mud without dredging. Crude removal and storage of contaminated mud is beginning to be replaced by in situ bio-remediation. |
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