Research finds phosphate matching Morocco’s reserves in disputed Spain-Morocco seabed: what to know

Phosphate rock beneath an Atlantic seamount claimed by both Morocco and Spain contains concentrations comparable to the deposits that underpin Morocco’s fertilizer industry, according to research published on June 22 in the scientific journal Minerals.

The study found phosphate levels of about 28% to 34% at Mount Tropic, around 500 kilometres off Morocco’s southern Atlantic coast. The findings sharpen the economic stakes around an already contested seabed that also holds cobalt, manganese and rare earth elements used in batteries, renewable energy equipment and defence technology.

Researchers analysed samples recovered from Mount Tropic and other northeastern Atlantic seamounts to determine how the phosphates formed and accumulated critical minerals. The deposits were already known, but the study provides a more detailed assessment of their composition and geological relationship to North African phosphate reserves.

The researchers also discovered that the underwater phosphate deposits formed around the same time as Morocco’s major onshore phosphate reserves. That suggests both were created through the same geological processes millions of years ago.

The study found that Mount Tropic also contains several minerals considered essential for the global energy transition and advanced industries. Estimates suggest the seamount holds nearly 15 million tons of phosphate rock, along with around 6,500 tons of rare earth elements and yttrium.

Above the phosphate layer sits a layer of mineral-rich rock. Researchers estimate it contains around 940,000 tons of manganese, 28,000 tons of cobalt, 47,000 tons of titanium. Under Europe’s MIN4EU classification system, the cobalt deposit is considered “large to super-large.”

These minerals are widely used in electric vehicle batteries, wind turbines, solar panels, defense equipment and other high-tech industries, making them increasingly important as countries race to secure reliable supplies.

The findings come as Morocco and Spain continue to disagree over who has rights to the seabed around Mount Tropic.

In 2020, Morocco approved two laws extending its maritime boundaries by establishing a 200-nautical-mile exclusive economic zone and seeking to extend its continental shelf to at least 350 nautical miles along its Atlantic coast, including waters off Moroccan Sahara. 

Spain objected, saying that maritime boundaries cannot be changed without agreement between neighboring countries under the UN Convention on the Law of the Sea. 

Madrid had already submitted its own request to the United Nations in 2014 to extend its continental shelf into much of the same area.

The competing claims are still awaiting a final decision from the UN’s Commission on the Limits of the Continental Shelf.

The legal picture became even more complicated after the 2024 ruling by the Court of Justice of the European Union, which said the Moroccan Sahara is not part of Moroccan territory. The decision affects the legal arguments surrounding Morocco’s claim to nearby waters. 

The minerals beneath Mount Tropic are unlikely to be extracted anytime soon. Sitting nearly three kilometers below the ocean’s surface, the seamount presents major engineering and technical challenges. 

Experts believe commercial mining remains at least two decades away, meaning the site’s strategic importance is likely to shape diplomatic and economic discussions long before any minerals are brought to the surface.