How does soil life develop in an abandoned sand extraction pit?

25 juli 2023

How does bottom life develop in sand extraction pits, in which sand has been excavated up to six metres below the seabed? This was investigated by the Royal Dutch Institute for Sea Research (NIOZ) and Wageningen Marine Research (WMR) in 2022 on behalf of the Sand from the Sea programme (Rijkswaterstaat and the LaMER Foundation), together with the OR ELSE project. For this, they compared the soil life in abandoned mid-deep sand extraction wells with surrounding reference areas using the NIOZ Triple D soil scraper.

Udo van Dongen

In the Netherlands, we extract a lot of sand from the North Sea, intended for coastal maintenance in the Netherlands and the construction of infrastructure and buildings. To keep meeting the growing demand for sand, we need to dig deeper and deeper in sand extraction pits. It used to be two metres, but nowadays we regularly dig about six metres deep into the seabed.

“Major effects are visible from this deeper sand extraction on the ecological development of the bottom life in such a sand extraction pit,” said Rob Witbaard, ecologist at the Royal Netherlands Institute for Sea Research (NIOZ). “Even 12 years after sand extraction, the biodiversity in old a sand extraction well still differs markedly from its surroundings. They are like scars on the seabed.”

Read more? How does benthic life develop in an abandoned sand extraction pit? – NIOZ