The Nereus submersible was lost at sea while exploring the Kermadec Trench at 10,000 meters during a May 2014 research cruise. During its life, it was planned for the ROV to help investigate the evolution and diversity of life in the deepest part of the ocean, and explore how species adapt to extreme environments. With the lost of the Nereus submersible, what other resources do we have to continue deep water exploration?


Nereus as is, is currently not replaceable, but it was insured at a replacement value of $3.1 million, and my understanding Woods Hole currently plans to replace it, though unlikely at this point that there's a solid timeline for this taking place.

Landers, fish traps, and sediment core samplers will still be actively used, but again, these are not really comparable to the areas of research that Nereus was able to cover.

UPDATE: These appears to be the last log entry for the Kermadec Trench 2014 expedition, and the official statement on the day of the event.

  • $\begingroup$ The issue is what happens to the science when one "instrument" like the Nereus is no longer available. The insurance is great, but the science that was going to be conducted would have to wait a while to see when/if they replace it. $\endgroup$ – arkaia May 21 '14 at 1:27
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    $\begingroup$ +1 because I had not considered that it would be possible to insure such a vehicle, but of course it makes much sense. $\endgroup$ – Mark Rovetta May 21 '14 at 1:43
  • $\begingroup$ Right, though not sure that Nereus' research agenda was public information, and even if it was, it's unlikely that it would be easy to quantify what research will be lost as a result that is truly irreplaceable. To me, the much larger issue is that given the degree to which the ocean is exploited, that even with Nereus, massive amounts of irreplaceable discoveries are likely lost all the time, and this is unlikely to change. Fact is Nereus is gone, and in my opinion, the best thing to do is move forward, not rehash what has been lost. $\endgroup$ – blunders May 21 '14 at 1:47
  • $\begingroup$ That said, if you really want to know the impact, I'd suggest just calling Woods Hole, since I've called them before, and they're pretty friendly. Only suggestion would be to attempt to get the information while you've got them on the phone. $\endgroup$ – blunders May 21 '14 at 1:51
  • $\begingroup$ As I work next to them it will be easy to ask, but the research from Nereus was going way beyond the Woods Hole community. Thanks for the comments and suggestions $\endgroup$ – arkaia May 21 '14 at 11:02

I think the greatest impact may be upon the careers of the investigators on the project. Decades of work can be invested in the planning and building of a submersible or space probe, it an inherently risky undertaking, if it gets destroyed in the process, who takes up the job of learning from the experience and trying again? Hopefully, institutions support people through the inevitable setbacks, but sometimes not.

The instrument itself is relatively easy to replace, but the expertise to use it properly is not so easy to come by. We wish all the persons involved the best.


In the latest EOS number there is an interview with Woods Hole Oceanographic Institution's scientist Timothy Shank in which he responds to the question. It seems that we are back to just snapshots and grad samples of the hadal ecosystem.

Eos: What research opportunities have been lost as a result of the loss of Nereus?

Shank: The ability of Nereus to do directed surveys and sample collection is critical for hadal research. Without it, we will be limited to the snapshot views of static instruments that only provide a limited perspective on what is an exceedingly complex ecosystem.

Eos: How much of the science that was planned to be done with Nereus can be done with other methods?

Shank: The capabilities Nereus provided were unique. We will be forced to rely on chance to retrieve sediment samples or macro fauna. Some things are simply not possible—such as near-bottom camera surveys or non-scavenging macro faunal recovery. The big-picture questions that will be affected include how much carbon is being sequestered in hadal sediments, how hadal ecosystems are structured, how human activity is affecting the lower one-third of the ocean’s depth, how much of what type of food is available to life in the deep ocean, and the range of adaptations life has evolved to cope with conditions in the deep ocean. Many of these are fundamental, first-order questions that we are only beginning to address.


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