Deep Sea Mining

Prelims: Current events of national and international importance | Science

Why in News?

A recent study on deep-sea mining reveals significant biodiversity loss, with sharp declines in marine species following test operations.

Deep Sea Mining – It is the process of retrieving mineral deposits from the ocean floor, hundreds or even thousands of meters below its surface (at depths greater than 200 meters).
Targeted Minerals – Like copper, cobalt, nickel, aluminium, manganese, zinc, silver, gold and rare earth elements are extracted from rocks called "polymetallic nodules”.
Key Mining Environments
- Polymetallic Nodules – Scattered across abyssal plains.
- Cobalt-rich crusts – Found on seamounts.
- Hydrothermal vents – Biologically rich but fragile ecosystems.

Abyssal plains - The huge flat bottoms of the deep ocean. Covered by fine-grained sediment like clay and silt, abyssal plains are also peppered with “abyssal hills” and underwater mountains known as seamounts.
Seamounts-A Mountain, usually formed of volcanoes, rising from the seafloor but not reaching above the surface of the water.

Abyssal Plain and Seamount

Current Status – Despite decades of interest, no country or company has successfully launched sustained commercial deep-sea mining.
Attempts by firms such as Nautilus Minerals (Papua New Guinea project) and Loke Marine Minerals collapsed financially, highlighting the high costs and risks involved.
Global Governance – International Seabed Authority (ISA) regulates mining in international waters under UNCLOS.
Benefits – Deep-sea mining minerals are essential for the green transition (renewables, batteries, smartphones).
Threat – Research suggests that it could cause irreversible species loss and ecosystem degradation lasting generations.
India’s Role – India launched the Deep Ocean Mission (2021) to explore and develop technologies for sustainable ocean resource use, with a budget of Rs.4,077 crore over 5 years.

To know about Samudrayaan Mission, Click here

Quick Fact

Key findings of the study

A large-scale test in the Clarion–Clipperton Zone (CCZ) of the Pacific Ocean recovered over 3,000 tonnes of nodules at a depth of 4,280 m.
The CCZ spans 6 million sq km and may hold 21 billion tonnes of nodules, making it the prime target for mining companies.
Methodology – Uses a Before-After-Control-Impact design over two years, comparing biodiversity before and after mining.
They found natural declines even before mining, but mining accelerated losses dramatically.

Impact on Marine Life

37% decline in macrofaunal density (large invertebrates like worms, crustaceans, molluscs, annelid).
32% reduction in species richness, showing significant biodiversity loss.
Researchers documented 788 species from 4,350 specimens, highlighting the immense diversity at risk.
Natural declines in species were already observed even before mining began (Nov 2020–Sept 2022).

References