Quirks & Quarks

Japan just mined the ocean floor and people want answers

Scientists warn that biodiversity loss from deep-sea mining will be unavoidable.

Japan just mined the ocean floor. Scientists are worried about what this will mean for sea floor biodiversity

5 years ago
Duration 1:00
Japan just mined the ocean floor. Scientists are worried about what this will mean for sea floor biodiversity

Japan's deep sea mining test

Japan just became the first country in the world to mine its seabed. The ocean floor is rich with resources that are becoming increasingly difficult to obtain on land, such as zinc, cobalt, copper, etc. Deep sea mining advocates think this could be the next gold rush.

In its test, Japan says they successfully crushed and then brought the ore to the surface. They conducted this test within their own territorial waters, otherwise known as their Exclusive Economic Zone or EEZ. And while the International Sea Bed Authority will eventually regulate deep sea mining in international waters, those rules aren't in effect yet. 

Why deep sea scientists are concerned

Many scientitsts believe that biodiversity loss among life at the bottom of the ocean will be unavoidable from deep sea mining. That was the conclusion of a paper published this summer in the journal Nature Geoscience, which was co-authored by Dr. Cindy Van Dover from Duke University and Dr. Craig Smith from the University of Hawaii. 

A mining machine is lowered into the sea to extract minerals from the seabed in the Okinawa Trough (Japan's Agency for Natural Resources and Energy)
The material Japan mined in their pilot test came from an inactive hydrothermal vent, which according to Dr. Tatsuo Nozaki from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is "several hundred metres away" from an active chimney. These extremely rare active chimneys are home to very specialized creatures that have evolved to live in these extremely hot habitats. 

Deep sea scientists are concerned about the the toxicity and turbidity of the material being dug up and its potential effects on nearby organisms. 

Japan released a statement that said, in part, they have "conducted research for the anticipated impact of the test on the surrounding environments and carefully confirmed that no serious impact might occur." When pressed for more details, Elisa Muroi from Japan Oil, Gas and Metals National Corporation (JOGMEC) in Vancouver said, they were "unable to provide with the answers, as the answers to your questions involve lot of confidential information."

The future of deep sea mining 

The potential risks go far beyond what might occur to organisms in and around hydrothermal vents. The International Seabed Authority has granted 27 contracts to explore for mining purposes - not only the polymetallic sulphides - or inactive hydrothermal vents, but also polymetallic nodules and cobalt-rich ferromanganese crusts. 

Pilot test of excavating and ore-lifting seafloor polymetallic sulphides (Japan's Agency for Natural Resources and Energy )
When it comes to mining the polymetallic nodules, which are potato shaped metal concretions made of manganese, cobalt, copper etc., the mining footprint would become much larger than it is for mining inactive hydrothermal vents. To mine these resource dense nodules, mining operations would essentially strip the habitat for organisms that have evolved there over millions of years.

There are still many unknowns when it comes to deep sea mining: 

- What kind of distrubtion of deep sea organisms is there at potential mining sites? 
- How will the sediment that gets kicked up affect deep sea life? 
- How will large scale mining affect water chemistry? 

As Dr. Cindy Van Dover puts it, "I think we could easily take one square metre of the seafloor away and not have a problem, or ten square metres or a hundred square metres for these manganese nodule beds, but what we don't know is the tipping point. Where is it going to matter for the health of the ocean. We have no clue, no clue at all. And if we screw it up, we can't fix it."