Located hundreds of miles offshore, the CCZ is an expansive deep-sea environment characterized by polymetallic nodules scattered across its seabed. These nodules contain valuable metals such as nickel, copper, manganese, and cobalt, essential for modern technologies like electric vehicle batteries and renewable energy infrastructure. The Canadian firm The Metals Company has announced plans to explore and potentially mine large swaths of this area, sparking scientific and environmental debates. Despite its economic allure, the ecological complexity of the CCZ remains poorly understood, particularly concerning its biodiversity and sensitivity to human-induced disturbances.

Marine mammals are among the most acoustically sensitive inhabitants of the marine ecosystem, relying heavily on sound for communication, navigation, and foraging. The first of two pivotal studies, published recently, systematically reviews the sensitivity of various taxonomic groups within the CCZ to anthropogenic noise generated by mining operations. Researchers reveal that just 35% of the species classes present in this area have been examined for potential noise impacts, underscoring significant knowledge gaps. Notably, soniferous fish and cetaceans — animals dependent on acoustic cues — exhibit heightened vulnerability to chronic, low-frequency noise pollution.

Deep-sea mining involves the extraction of polymetallic nodules using heavy machinery that disturbs the ocean floor, generating wide-reaching noise and sediment plumes. Sound propagates efficiently underwater, often traveling through specialized oceanic channels like the SOFAR channel, allowing noises to affect marine organisms across hundreds of kilometres. Chronic exposure to such noise can disrupt intricate behaviors essential for survival, including mating calls, mother-calf bonding, and hunting strategies. The cascade effects on marine food webs and ecological networks could be profound, yet remain poorly quantified.

The second study offers groundbreaking insights derived from extensive fieldwork aboard the Greenpeace vessel Arctic Sunrise. Over a focused 13-day period, the researchers employed both visual surveys and passive acoustic monitoring techniques to detect the presence of cetaceans in the CCZ. Sonar and hydrophone recordings registered 74 distinct acoustic signals attributable to whales and dolphins, while observers logged six visual sightings. Species identified included endangered sperm whales, Risso’s dolphins, common dolphins, and numerous unidentified dolphin groups. These observations confirm that this remote deep-sea landscape supports a diversity of cetacean life.

The presence of sperm whales, a species listed as vulnerable on the IUCN Red List, is particularly alarming given their known sensitivity to underwater noise and long-term exposure risks. These marine mammals use low-frequency clicks for echolocation and communication, which mining noise could mask, leading to behavioural changes such as habitat abandonment or impaired foraging. Displacement from critical habitats could jeopardize reproduction and survival, compounding existing pressures from climate change and ocean pollution. The notion that the CCZ might be a significant habitat or migratory corridor amplifies conservation concerns.

Noise pollution from mining extends beyond cetaceans to affect a myriad of other taxa within the CCZ ecosystem. Soniferous fish, crustaceans, and benthic invertebrates show sensitivity to acoustic disturbances, which can alter behaviors like spawning, feeding, and predator avoidance. The sediment plumes arising from mining excavation pose additional threats by smothering benthic organisms, disrupting filter-feeders, and impairing visual and chemical cues essential for species interactions. Limited data on plume dynamics and sediment dispersion hinder accurate risk assessments, creating an urgent call for multidisciplinary research.

Experts emphasize that the CCZ houses long-lived, slow-growing species adapted to a stable and resource-scarce environment. Disturbances to these communities may have irreversible impacts, given their limited reproductive rates and ecological resilience. Conservation frameworks traditionally focused on coastal and shallow-water ecosystems may not be adequate to protect these deep-sea habitats. Consequently, the precautionary principle is advocated, ensuring that seabed mining initiatives undergo rigorous environmental impact evaluations and incorporate noise mitigation strategies before any commercial activities proceed.

Dr Kirsten Young, a marine ecologist at the University of Exeter and lead author of the cetacean study, underscores the difficulty inherent in predicting ecological outcomes in this largely unexplored environment. She highlights that many ocean species, including marine mammals, are finely tuned to their acoustic surroundings. The interplay between mining-generated noise and habitat use remains difficult to model but is thought to influence crucial biological processes. “Chronic, pervasive noise” may act as a pervasive stressor with far-reaching ecosystem consequences, necessitating both scientific attention and regulatory oversight.

Greenpeace International’s Louisa Casson, participating in the Arctic Sunrise expedition, echoed these concerns by labeling the planned mining operations a “dangerous industry” that threatens fragile deep-sea ecosystems. Activist groups advocate for a moratorium on seabed mining until more is understood about the potential impacts on marine biodiversity and ecosystem functions. Their position reflects a broader debate about balancing technological advancement and resource extraction with the stewardship of ocean health and species protection.

The syntheses derived from these two seminal papers provide a vital foundation for future environmental policymaking regarding ocean mining. Published in the journals Frontiers in Marine Science and Marine Pollution Bulletin, these studies not only document the vulnerability of cetaceans and other taxa but also emphasize the glaring knowledge voids hindering impact assessments. Stakeholders must engage interdisciplinary experts, incorporate advanced acoustic sampling, and foster international cooperation to mitigate irreversible ecological damage in the CCZ and other deep-sea mining hotspots.

As the global demand for metals intensifies, the CCZ’s polymetallic nodules will undoubtedly attract increasing industrial interest. Nevertheless, the mounting evidence presented by these researchers makes a compelling argument for urgent caution. Protecting one of the planet’s largest and most mysterious oceanic biomes is not merely an environmental imperative; it is crucial to maintaining the biological integrity of the Earth’s interconnected marine systems. Future research must prioritize filling scientific gaps around noise impacts, sediment plume behavior, and deep-sea species ecology to inform responsible management of these precious underwater frontiers.

Subject of Research: The impact of deep-sea mining noise and activities on marine mammals and other taxa in the Clarion Clipperton Zone, Eastern Pacific Ocean.

Article Title: Threatened cetaceans in a potential deep seabed mining region, Clarion Clipperton Zone, Eastern Pacific.

News Publication Date: 24-Jun-2025

Web References:

• https://www.sciencedirect.com/science/article/abs/pii/S0025326X25006101
• http://dx.doi.org/10.3389/fmars.2025.1511075/abstract

Image Credits: Credit: Leonidas Karantzas

Keywords: Marine conservation, Noise pollution, Cetaceans, Marine biodiversity

At the core of PCM’s technology is a deceptively simple yet highly effective device: a black disc engineered with a specialized anti-fouling coating. These discs float on the surface of traditional open evaporation ponds—vast shallow basins containing mineral-rich brine—and absorb sunlight much more efficiently than the pond surfaces themselves. Acting like miniature solar collectors, the discs convert incoming solar radiation into thermal energy, substantially accelerating the evaporation process and thereby increasing the rate at which valuable minerals crystallize and can be harvested.

While conventional evaporation ponds disperse solar energy diffusely across large surface areas with less than 50% efficiency, PCM’s discs have demonstrated over 96% efficiency in converting sunlight into heat in real-world applications. This near-total absorption of solar energy effectively supplements the sun, turning these ponds into highly productive and compact evaporation systems. The concept has been vividly described by Princeton’s civil and environmental engineering professor Z. Jason Ren as “adding a second sun” to mineral extraction ponds, highlighting the stark contrast in energy conversion performance.

Field tests carried out in northern Chile—a global hotbed for lithium and nitrate mining—illustrate the transformative impact of this technology. In collaboration with Sociedad Química y Minera de Chile (SQM), one of the world’s leading chemical companies specializing in mining and agriculture, PCM deployed their floating discs in operational evaporation ponds. Results showed evaporation rates increased by an impressive 40 to 122 percent compared to traditional open ponds, variations depending on the specific brine composition. This drastic improvement not only boosts mineral yield but also shortens production cycles, directly addressing supply chain bottlenecks impacting clean energy technologies like electric vehicle batteries.

The implications of PCM’s technology extend beyond just improving output; by elevating the effectiveness of existing ponds, this innovation could curb the sprawling expansion of new evaporation sites. Conventional lithium extraction operations often require vast land areas—stretching across hundreds of square miles—to meet demand, a footprint that poses significant environmental challenges including habitat disruption and water resource depletion. PCM aims to substantially reduce this spatial footprint. More efficient ponds could mean fewer sites with smaller environmental impact, allowing mineral production to scale sustainably alongside global efforts to combat climate change.

PCM’s story is deeply intertwined with Princeton’s rich innovation ecosystem. The company originated in the academic collaboration between Professor Ren and Sean Zheng, who joined Ren’s lab as a Distinguished Postdoctoral Fellow at the Andlinger Center for Energy and the Environment. Their initial investigations stemmed from fundamental research into brine evaporation enhancement, which culminated in a scientific paper exploring the thermodynamics and interfacial processes governing solar evaporation. Recognizing the real-world potential, they leveraged university-supported entrepreneurship programs to translate laboratory knowledge into commercial technology.

Participation in initiatives such as the National Science Foundation’s I-Corps and Princeton’s IP Accelerator program provided crucial market insights and sharpened PCM’s business strategy by aligning scientific innovation with industry needs. These programs helped the founders discern that some technical phenomena that intrigued researchers held less significance for commercial viability, guiding them toward focusing on pragmatic operational improvements. Additionally, the START Innovators program fostered the transition from academic experimentation to entrepreneurship, equipping the team with essential skills in business planning and venture creation while nurturing continued technological development.

Support from Princeton’s Keller Center for Innovation in Engineering Education further accelerated PCM’s journey. The Design for Impact program, which blends financial support with expert mentorship, prepared the founders to hone their pitch and navigate the complexities of early-stage commercialization. This comprehensive support network exemplifies the multifaceted approach required to bridge the gap between academic breakthroughs and industry-scale deployment. According to Craig Arnold, Princeton’s Vice Dean for Innovation, PCM exemplifies how leveraging interdisciplinary university resources catalyzes translational research that can profoundly impact global challenges.

PCM’s rapid progress underscores the synergy between rigorous research and entrepreneurial drive. From testing small-scale prototypes in makeshift setups such as kiddie pools to deploying fully operational products in South American mineral facilities, their trajectory reflects a model of agile development anchored in real-world validation. This approach not only enhances product performance but also uncovers new research avenues. For instance, field data revealed that the solar-absorbing discs maintained higher surface temperatures relative to open ponds, with less heat transmitted to the pond bottom—a thermal stratification effect influencing mineral solubility and crystallization dynamics. Such insights fuel ongoing investigations into brine chemistry optimization at Princeton.

The partnership with SQM and other industry players is instrumental in advancing both scientific understanding and commercial deployment. Collaborative pilot projects substantiate not only the feasibility of the technology but also its adaptability across various brine compositions and extraction contexts. This iterative feedback loop between laboratory research and field application exemplifies a convergence of innovation and practicality critical for sustainable resource extraction, setting a precedent for future technologies to follow.

Beyond its immediate commercial promise, PCM’s innovation intends to inspire broader shifts within the scientific community. Professor Ren advocates that academic researchers view their work through the lens of societal impact, extending beyond publications to tangible solutions addressing pressing resource and environmental challenges. The success of PCM highlights the tangible benefits universities can offer by fostering ecosystems that support researchers in taking bold steps towards entrepreneurship without sacrificing academic rigor.

In an era where the demand for lithium and other critical minerals underpins the global transition to cleaner energy futures, technologies like PCM’s represent vital tools in minimizing environmental harm while maximizing resource efficiency. By doubling the efficiency of solar evaporation systems through advanced materials and clever design, PCM is poised to help build a more sustainable and resilient supply chain for the technologies driving the 21st-century energy transition.

As PCM moves toward full commercialization, the future holds promising vistas not only for mineral extraction but also for expanded scientific inquiry and sustainable engineering. Its story exemplifies how strategic university-industry partnerships, coupled with innovative technology and entrepreneurial zeal, can accelerate solutions to some of the most challenging problems facing humanity today.

Subject of Research: Not applicable

Article Title: Interfacial solar evaporation for sustainable brine mining

News Publication Date: 10-Feb-2025

Web References:

• Princeton Critical Minerals
• Nature Water Article
• I-Corps Northeast Regional Hub
• HAX Program

References:

• Ren, Z. J., Zheng, S., Khandelwal, A., Oelckers, B. "Interfacial solar evaporation for sustainable brine mining," Nature Water, 2025. DOI: 10.1038/s44221-025-00394-y

Image Credits: Bumper DeJesus, Andlinger Center for Energy and the Environment

Keywords: Solar evaporation, Lithium extraction, Critical minerals, Brine mining, Renewable energy, Evaporation ponds, Sustainable mining, Princeton University, Innovation ecosystem, Clean technology, Mineral production, Environmental engineering