Apart from fresh water, sand and gravel are the most exploited substances on Earth. Used for most new constructions, they are simply treated as insignificant natural re-sources. But besides constituting the foundation for human subsistence, ecological systems depend on them. It is becoming increasingly difficult to find new areas suitable for extraction on land, pushing extractions towards the sea, where it is invisible to the human eye. This investigation into the practice of dredging for marine sand and gravel in the North Sea and the Baltic Sea has revealed the necessity for more comprehensive examinations and understandings of the complex ecological system of the seabed in order to provide a more accurate assessment of externalities. Three significant externalities are uncovered, suggesting stopping gravel extraction at sea, which underlines the urgent need for construc-tion strategies that are not based on primary sand and gravel.
Holm et al. (Wed,) studied this question.