On parts of the shoreline in the Moroccan beach town of Tangier, something is amiss. Though the ocean is there — its waves lapping, crashing and roaring as they have since time immemorial — it is not a place for long days of lazing on soft sand. Because there isn't any.

Instead of a rolling golden strand, there is a rockscape with lunar-like formations. Though spectacular to behold, they aren't natural phenomena — but actually just former beaches stripped bare by large-scale theft of sand.

But why steal it? "We have a lot of sand, but we also have a lot of demand," Hermann Kessler from the German Environment Agency (UBA) told DW.

It is used in many, many things. From toothpaste and plaster to stone-washed jeans; crockery, kitchen sinks and toilet bowls; from windows and beer bottles to silicon chips that are used in items from smart phones to cars.

But by far the biggest consumer is the construction industry, which uses sand to produce bricks, asphalt and concrete. It takes around 200 tons (400,000 pounds) of the stuff to make a mid-sized house; to build a kilometer of highway takes 30,000 tons; and a nuclear power plant around 12 million tons.

Construction consumes huge amounts of sand. A single kilometer of highway requires 30,000 tons

A recent report by the United Nations Environmental Programme (UNEP) estimated the annual global consumption of sand and gravel to exceed 40 billion tons.

"Sand is a fossil resource," said researcher Kiran Pereira, who founded sandstories.org to raise awareness of the issue. "It takes millions of years to form — but a mine can be exhausted in decades," she pointed out.

"We need to recognize and value the ecosystem services provided by sand, many of which are irreplaceable."

Read: The house that trash built

Construction, corruption and crime

How critical the situation is varies greatly from location to location.

"We won't be running out of sand here in Germany," said Kessler, who is responsible for resource conservation at UBA. "But globally, it's a very different story."

The biggest sand importer in the world is Singapore. In the past 40 years, the small and crowded island has used large-scale land reclamation — a process that entails filling in shallow waters to be able to build on them — to expand by its land mass by 130 square kilometers (about 50 square miles). That practice requires vast quantities of sand.

There was a time when much of it came from nearby Indonesia, Malaysia, Vietnam and Cambodia — but all four countries have now banned Singapore from exporting their beaches. This has pushed sand's metric ton price up from €2.55 (3.00 dollars) to €161. And that increase has had impact.

"The sand business is very corrupt," Kessler said, adding it is often conducted illegally, and is done by people who "don't shy away from threats and even murder."

Criminal gangs are stealing sand in countries ranging from Jamaica to Nigeria. India even has a sand mafia, known for its ruthlessness.

Some gangs will drive onto a beach with excavators and large trucks and help themselves to as much as they can in a single night — while others use simple hand tools to fill bags they load onto mules to take directly to nearby construction sites.

Environmental impact

Another method of extraction is to use suction dredge barges, which act like giant vacuum cleaners that suck up the sand from the ocean floor in shallow waters. This wreaks havoc on the ocean floor.

"Anything that gets pumped up by one of these suction dredge barges is essentially dead," said Kim Detloff, head of marine conservation at Nature and Biodiversity Conservation Union (NABU) in Germany. "There are studies that show sand habitats don't recover at all after they've gone through this."

This practice, like that of loading half a beach onto trucks in the dead of night, can also lead to coastal erosion. If miners take too much from the sloping shallows, it can cause the the beach to slide toward and eventually into the ocean, leaving nothing behind to protect the shore against the force of the waves.

Though land mining in sandy inland areas can be less damaging if done efficiently, that is not always the case.

"If you cut into the aquifer, which usually happens, there is always the danger that contaminants can enter the groundwater," said Till Hopf, who is in charge of conservation and land use at NABU.

Such contamination can be chemicals released during the mining process; or also biological contaminants like bacteria, which are normal in surface water, but are filtered out as that water seeps through the sediment.

Natural erosion processes are often combated by sucking sand up from the ocean floor and depositing on the beach. The effects are devastating for nearby marine life

No easy fix

There is no silver bullet to solve this problem, though there are various efforts underway to find alternatives.

Two German entrepreneurs are currently experimenting with desert sand, which in a twist of irony — given that the oil-rich countries of the Persian Gulf region are among the biggest importers — is too wind-polished to use in concrete.

Though it's still early days, they have found a way to combine smooth desert grains with synthetic resin to create polymer concrete, which is even more durable than its conventional counterpart.

In light of environmental problems around building with concrete, there's also concrete recycling — but for that to make economic and environmental sense, there needs to be enough old concrete close to the new construction site.

Watch: Concrete answers to a recycling problem

Likewise, there's a case to be made for the more widespread use of wood and more efficient mining methods.

Singapore is the world's biggest importer of sand. The crowded city state uses it to add to its territory and to construct its many skyscrapers

As things stand, miners usually seek a very specific grain size and discard the rest of the sand — although this could often be used in construction as well, reducing the need for further extraction.

Fossil material

Unfortunately, none of these approaches are immediate solutions to such a large-scale issue.

Part of the problem is construction industry's attachment to concrete. Architects, engineers and builders all know how to work with concrete and have the tools to do it, which provides no incentive for innovation.

In that sense, concrete — and by extension sand — is a lot like oil. We use it to solve many different problems, for which it will take extra effort to find alternatives.

"We need sand, there is no way around it," concluded Kessler. "But that doesn't mean we shouldn't try to use it more ecologically."