Around six billion tonnes of sand are extracted from the bottom of the ocean and coastal areas every year, disrupting ecosystems and affecting nearby communities, according to data compiled by a new UN initiative launched in Geneva.
Sand is the second-most exploited natural resource after water. It is used in buildings, bridges, windows and solar panels, and yet we barely keep track of its extraction.
The UN Environment Programme (Unep) launched a new online platform on Tuesday that can trace dredging activities in the world’s seas and beaches. The Marine Sand Watch has been trained with artificial intelligence to detect the movement patterns of dredging vessels, which it can track through the signals emitted by all ships for marine traffic purposes.
“We need to consider sand as a strategic material rather than a common one,” said Pascal Peduzzi, director of Grid-Geneva, a data analysis centre created by the UN Environment Programme (Unep), the Swiss government and the University of Geneva, which is behind the platform.
Some 50bn tonnes of sand are mined from quarries, land, riverbeds, shores and the seafloor every year, according to Unep. Data gathered on the platform from 2012 to 2019 has revealed that around six billion tonnes of that comes from marine areas – the equivalent of one million trucks every day, said Peduzzi.
Why it’s problematic
Dredging entails either crunching, scooping up, grabbing or vacuuming sand, rock and other sediments. When taken from a static environment, for example from quarries or by crushing rocks, it has little lasting impact on the environment.
But when it is removed from rich life habitats such as riverbeds, estuaries, coastlines and the sea floor, it can upset ecosystems by killing microorganisms, removing vital nutrients, and causing sediments to stir up and deposit elsewhere. In coastal areas, sand acts as a barrier against storms and tidal waves as well as salinity.
As climate change drives sea levels rise, these natural walls are all the more critical to protect low-lying coastal areas.
But the marine habitats are losing sand to dredging at a pace that is quickly catching up to the rate at which they can naturally replenish, estimated at between 10 and 16bn tonnes of sand reentering the ocean each year.
How the platform can help
The platform not only provides the number of dredging vessels but also maps out operations worldwide, including the creation of artificial islands, new harbours, replenishing of beaches and cleaning up canals.
Due to a lack of global regulations and monitoring, industry practices vary a lot from one country to another, making it hard to assess the environmental impact, said Arnaud Vander Velpen, sand industry and data analytics officer at Grid-Geneva, who developed the tool’s methodology.
“Very few countries know the reserves of sands and of marine sand that they have available. In the light of sea rise, it's extremely important that countries take stock of the amount of usable sand that they have offshore to shore up their coastlines,” he said, citing Belgium as one of the exceptions. The country has estimated it has 80 years worth of sand left if it continues to extract it at the current pace.
Belgium is one of the top countries with the largest dredging fleets, preceded by China, the Netherlands and the United States, Vander Velpen noted, responding to questions by reporters in Geneva.
He added that the platform reveals that the world’s hotspots for dredging activity are the South China Sea, the Persian Gulf, the North Sea and the east coast of the United States.
Vander Velpen said the the tool was meant to be “a capacity building tool to provide data and transparency to all stakeholders” and that he hoped it would spark a conversation on how to extract sand in a sustainable way.
Real-time monitoring on the horizon
The platform for now has information up until 2019 but Peduzi said they would update it to include data up to 2023 and would like to see it provide in the longterm “near real time” data about what these vessels are up to.
Since the platform works with the signals emitted by vessels, it can only track those that are operating legally and with a tracking device. Small-scale, artisanal mining in shallow areas along the coastline, for example, are not included in the data. But Peduzzi said the organisation had “ambitions” to go beyond and integrate other data collecting methods such as using drones or remote sensing with satellite imagery to fill in those gaps.
The Marine Sand Watch, he said, is one of the components of a larger proposal for a Global Sand Observatory, which states are set to discuss later this week in Geneva at a meeting on minerals and metals.