COASTAL STRUCTURES, WASTE MATERIALS AND FISHERY ENHANCEMENT

Current U.K. practice relating to the disposal of material at sea is r eviewed. The use of stabilization technology relating to bulk waste ma terials, coal ash, oil ash and incinerator ash is discussed. The exten sion of this technology to inert minestone waste and tailings, contami nated dredged sediments and phosphogypsum is explored. Uses of stabili zed 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 frequen cy. This is of particular concern along the southern and eastern coast s of the U.K. The emphasis of coastal defenses is changing from ''hard '' seawalls to ''soft'' options which include offshore barriers to red uce wave energy reaching the coast. Stabilized waste materials could b e included in these and other marine constructions with possible econo mic benefit. Ministry of Agriculture, Fisheries and Food (MAFF), the r egulatory authority in England and Wales for marine disposal/construct ion, policy regarding marine structures and fishery enhancement is out lined. A case is made for the inclusion of fishery enhancement feature s in future coastal structures. Examples of the productivity of man-ma de 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.