Michael Clarke, Environmental Manager at The Metals Company, brings over 30 years of conservation biology experience to impact assessment of potential mining in the CCZ. Mike explains the details of how TMC goes about conducting one of the largest-ever marine environmental baseline programs, the challenges of gathering and interpreting deep-sea data, and the critical trade-offs between land-based and ocean resource extraction.

From sediment plumes to carbon concerns, Mike breaks down what the data shows—and what it doesn’t—when it comes to the potential environmental impact of deep-sea mining. If you’re trying to understand the nuances of deep-sea mining’s environmental footprint, and how these decisions balance against terrestrial mining pressures, this episode is a must-listen.

Shortly after this was recorded The Metals Company made the first ever submission for a commercial recovery permit in international waters under U.S. law. Details can be found on their website: https://investors.metals.co/news-releases/news-release-details/world-first-tmc-usa-submits-application-commercial-recovery-deep.

Topics Covered:

* Michael’s global conservation background and path to DSM

* TMC’s $250M environmental baseline study

* Noise, light, sedimentation, and carbon impacts: findings and misconceptions

* Technical challenges of offshore environmental science

* The trade-offs between deep-sea and Indonesian rainforest nickel mining

* How science feeds into decision-making for sustainability

* Why polarized narratives around deep-sea mining often miss the real questions

Follow Mike on LinkedIn https://www.linkedin.com/in/michael-clarke-6575501b/

Resources Mentioned:

* International Seabed Authority Publications https://www.isa.org.jm/publications/

* Polymetallic Nodule Research Alliance https://noduleresearch.com/

* TMC’s Research web page https://metals.co/research/

* SMARTEX study https://www.nature.com/articles/s41586-025-08921-3

⏱️ Timestamps

02:08 — Early career: conservation work, invasive species research, global fieldwork08:23 — Transition to industrial EIAs and mining projects09:41 — Joining The Metals Company and focus on deep-sea mining12:29 — Trade-offs and decision-making in environmental assessments17:07 — How deep-sea environmental studies are designed and conducted20:07 — Research logistics: campaigns, challenges, and COVID adaptations22:36 — Partnering with universities and ensuring independent data publication27:22 — Key technical challenges in deep-sea sampling and monitoring34:48 — Findings on noise impacts from mining operations39:32 — Managing zones of impact and minimizing environmental spread42:34 — Sediment and midwater plume behavior and impact modeling58:06 — Understanding cumulative impacts and the role of regulation1:04:15 — Other impacts: carbon release, lights, and habitat loss1:06:56 — Protecting biodiversity: mining strategy and protected areas1:10:40 — Funding environmental research and trust in scientific integrity1:14:45 — Long-term monitoring plans and Pacific Islander involvement1:17:50 — Reflections on environmental consulting and early design influence1:20:38 — Media misrepresentation and public misunderstanding of research1:24:09 — Trade-offs: deep-sea mining versus rainforest destruction1:29:03 — Closing thoughts, resources, and where to learn more

Theme music Tamarack by Jesse Matas

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit tradingoff.substack.com