New Research: Ecological effects sand extraction

25 juli 2023

Because of sea level rise, we need more and more sand from the North Sea to protect our coast. With the OR ELSE project, new research is starting that focuses on optimizing sand extraction in the North Sea ecologically to keep the marine ecosystem healthy and provide us with food. Together with an interdisciplinary team, new knowledge on the effects of sand extraction will be developed over the next five years. The project is led by Wageningen Marine Research.

In the Netherlands, much sand is extracted from the North Sea for coastal protection, as construction sand for roads and residential areas, and for concrete and masonry sand. Every year, a piece of seabed as big as the isle of Schiermonnikoog is excavated by about eighty centimetres deep. Our sand demand is growing, because of sea level rise but also because of the increasing demand for housing.


Effects of sand extraction in the North Sea

Our conurbation is protected by dunes. These are beautiful natural systems that protect us from the sea. We want these dunes to grow in a natural way. To let them grow according to rising sea levels, we need sand nourishments. The sand needed for this is extracted from the North Sea at a minimum water depth of 20 metres. A spatial reservation area has been designated for this purpose.

When sand is extracted, damage is done to life in and on the seabed. Shells, worms, starfish and fish get sucked up and die. In addition, sand extraction can cloud the water, resulting in a negative effect on the growth of algae, the basis of the marine food chain.

So how to do it?

As we need more and more sand, we need to think carefully about how we want to leave the North Sea floor, according to marine ecologist Martin Baptist. “If you extract shallow sand, you do ecological damage to a huge area. If you extract it deeper, you kill less marine life, but the sea bed needs more time to recover,” he says. “For example, we have already seen that in the sand extraction pit for the Maasvlakte 2, which was up to 20 metres deep, a lot of silt is caught. This is worrying, because the Dutch coast is very important as a rearing ground for commercial flatfish species such as sole and plaice.”

Read more? Research ecological effects sand extraction honoured in NWA ORC call – WUR