Coastal Structures, Waste Materials and Fishery Enhancement

Current U.K. practice relating to the disposal of material at sea is reviewed. The use of stabilization technology relating to bulk waste materials, coal ash, oil ash and incinerator ash is discussed. The extension of this technology to inert minestone waste and tailings, contaminated dredged sediments and phosphogypsum is explored. Uses of stabilized wastes are considered in the areas of habitat restoration, coastal defense and fishery enhancement. It is suggested that rehabilitation of marine dump sites receiving loose waste such as pulverized fuel ash (PFA) could be enhanced by the continued dumping of the material but in a stabilized block form, so creating new habitat diversity. Global warming predictions include sea level rise and increased storm frequency. This is of particular concern along the southern and eastern coasts of the U.K. The emphasis of coastal defenses is changing from “hard” seawalls to “soft” options which include offshore barriers to reduce wave energy reaching the coast. Stabilized waste materials could be included in these and other marine constructions with possible economic benefit. Ministry of Agriculture, Fisheries and Food (MAFF), the regulatory authority in England and Wales for marine disposal/construction, policy regarding marine structures and fishery enhancement is outlined. A case is made for the inclusion of fishery enhancement features in future coastal structures. Examples of the productivity of man-made structures are given. Slight modification of planned structures and inclusion of suitable habitat niches could allow for the cultivation of kelp, molluscs, crustacea and fish.