Action: Remove discarded sediment material from the seabed following cessation of aggregate extraction
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of removing discarded sediment material from the seabed following cessation of aggregate extraction on subtidal benthic invertebrate populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.
'Aggregates’ is the collective term for sand, gravel and crushed rock. They are used as raw materials for the construction industry as well as for beach replenishment schemes (De Groot 1996). During extraction, a portion of sediment is often discarded, being unwanted or in excess depending on the industry requirements, and left on the seabed, changing its characteristics and further impacting invertebrates through habitat modifications. Following the cessation of aggregate extraction, this discarded material could be removed from the seabed through additional dredging (Cooper 2013), thereby removing the threat and potentially allowing natural recovery (Cooper et al. 2011). Additional evidence for intervention related to sediment discard during aggregate extraction and other activities are summarised under “Threat: Energy production and mining – Limit, cease, or prohibit sediment discard during aggregate extraction”, and “Set limits for change in sediment particle size during rock dump”.
Cooper K.M. (2013) Setting limits for acceptable change in sediment particle size composition: Testing a new approach to managing marine aggregate dredging. Marine Pollution Bulletin, 73, 86–97.
Cooper K., Ware S., Vanstaen K. & Barry J. (2011) Gravel seeding - A suitable technique for restoring the seabed following marine aggregate dredging? Estuarine, Coastal and Shelf Science, 91, 121–132.
De Groot S.J. (1996). The physical impact of marine aggregate extraction in the North Sea. ICES Journal of Marine Science, 53, 1051–1053.