Sand mining harms marine environments, new data suggest

New data from the newly launched platform, Marine Sand Watch, suggest that the dredging industry is extracting about six billion tonnes of sand from the marine environment annually.

Experts say the extraction of sand can have numerous impacts on the marine environment such as harming biodiversity, polluting water and making coastlines more vulnerable to sea level rise.

While the sand mining industry is currently operating at unsustainable levels, experts say there are solutions to mitigate its damage.

New data suggest that the extraction of sand from marine environments – known as “sand mining” – is happening at an unsustainable rate across the world. However, experts say there are solutions to mitigate this activity’s damaging effects.

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Recently, the UN warned that the dredging industry is extracting about six billion tonnes of sand from the marine environment each year – roughly equivalent to the carrying capacity of one million dump trucks. Not only does this put marine biodiversity and the ecosystem at risk, it makes coastal communities more vulnerable to the impacts of climate change, including sea level rise.

These data were extracted from the Marine Sand Watch, a global data platform that tracks and monitors the dredging of sand, clay, silt, gravel and rock in the marine environment. The platform uses the same algorithm as the fishing monitoring platform, Global Fishing Watch, gathering information on dredging vessels through Automatic Identification System (AIS) signals and Artificial Intelligence (AI).

Sand mining is “invisible because it’s underneath the water,” Pascal Peduzzi, the Director of GRID-Geneva at UN Environment Programme (UNEP), the organisation that launched Marine Sand Watch, told Mongabay.

“So, this platform is making the invisible visible, and we are shedding light on this industry that so far was a bit under the radar,” he added.

Sand and other natural resources are extracted for a number of purposes, including the making of cement or concrete, buildings, roads or other infrastructure. And while sand mining can make coastlines more vulnerable to sea level rise, sand is also mined for beach replenishment projects to protect coastlines against sea level rise.

Peduzzi said that many sand mining operations used equipment that appeared to be “giant vacuum cleaners” to suck up sand from the seafloor while also “sterilising the bottom of the sea.

“If you do it on a small scale, then you leave enough time for life to recover and the impacts can be mitigated. But if you continue massive extraction and you are doing it at a large scale, then we see a disappearance of life. And that’s what we are observing worldwide, not only from the dredging industry, but also because of fishing, deforestation and change in habitat,” Peduzzi said.

According to him, sand mining in the ocean can have a range of impacts, including the destruction of biodiversity and habitats, water pollution and altered water quality and increased vulnerability of coastlines to sea level rise.

Data from the new platform show that sand mining is happening at “hotspots” in the North Sea, South East Asia and the East Coast of the United States. However, there are differences in how sand extraction is practiced in different parts of the world, according to Vera Van Lancker, a marine geologist at Royal Belgian Institute of Natural Sciences.

“In the North Sea, sand extraction is not taking place within the active beach nearshore system. For instance, in the Netherlands, extraction can only take place deeper than 20 metres (65.6 feet). On the Belgian shelf as well, extraction is only allowed in the zone where you would not have an active exchange of sediments of sand with the beach or with the nearshore. This knowledge that you should not be doing that is quite widespread, but indeed, there are cases globally, especially near small islands, where this would occur,” Van Lancker told Mongabay.

Sand mining isn’t a practice that only happens in and around the ocean – it also takes place on land. A report published in 2022 by UNEP revealed that industries were extracting an estimated 40 to 50 billion tonnes of sand, gravel, crushed stone and aggregates from the global environment, including the ocean. The report suggested that this amount of extracted material has exceeded the planet’s natural replenishment rates.

While the impacts of sand mining are widespread, Peduzzi said there were solutions to the issue. For instance, industries can try to minimise the wastage of sand and other resources and recycle materials. Additionally, companies can dredge in a more “natural shape” in the marine environment and leave 50 to 60 centimetres (20 to 24 inches) of sand at the bottom, which could allow more biodiversity to return to the area, he said.

“The simple fact is that the way we are dealing with natural resources is totally unsustainable. And this story about sand is the same about overfishing, the same about deforestation, the same about the problem we have for climate biodiversity of pollution. We just have to think differently,” he added.

Alberts is a senior staff writer for Mongabay. Follow her on Twitter @ECAlberts.