\n By ALEXA ST. JOHN with AP\n<\/p>\n
\n Published on
\n 09\/11\/2025 – 8:02 GMT+1\n <\/p>\n
Drilling for minerals deep in the ocean could have immense consequences for the tiny animals at the core of the vast marine food web \u2014 and ultimately affect fisheries and the food we find on our plates, according to a new study.<\/p>\n
Deep-sea mining means drilling the seafloor for \u201cpolymetallic nodules\u201d loaded with critical minerals including copper, iron, zinc and more. <\/p>\n
While not yet commercialised, nations are pursuing deep-sea operations amid rising demand for these minerals in electric vehicles and other parts of the energy transition, as well as for technology and military use.<\/p>\n
The researchers examined water and waste gathered from a deep-sea mining trial in 2022.<\/p>\n
What the study discovered<\/p>\n
University of Hawaii researchers studied an area of the Pacific Ocean called the \u201ctwilight zone,\u201d about 200 to 1,500 meters below sea level. Their peer-reviewed findings, published Thursday in the Nature Communications scientific journal, say mining waste could affect anything from tiny shrimp smaller than 2 millimetres long to fish 5 centimetres long.<\/p>\n
That’s because, after mining companies bring the mineral-rich nodules up to the surface, they have to release excess seawater, ocean floor dirt and sediment back into the ocean. That creates a murky plume of particles about the same size as the naturally occurring food particles normally eaten by the zooplankton that swim at that depth.<\/p>\n
That’s a little more than half of the zooplankton in the ocean. If those organisms eat the waste particles \u2014 what senior study author Brian Popp called \u201cjunk food\u201d \u2014 then that affects 60 per cent of micronekton that eat the zooplankton.<\/p>\n
And that undernourishment is a problem because these tiny organisms are the food source up the chain, ultimately affecting commercially important fish such as mahi mahi or tuna.<\/p>\n
\u201cSurface fish can dive down deep into the water; they feed on organisms down at depth,\u201d said Michael Dowd, study lead author and oceanography graduate student. <\/p>\n
\u201cIf these organisms down at depth are no longer present because their food web has collapsed, then that can impact higher food webs and more commercial interests.”<\/p>\n
Impact on the water and alternative sources<\/p>\n