A recent study led by oceanographers at the University of Hawai‘i at Mānoa has shed light on the potential threats posed by deep-sea mining to some of the ocean’s most vulnerable and enigmatic creatures: sharks, rays, and chimaeras. These ancient cartilaginous fishes, many of which are already imperiled by overfishing and habitat loss, face new risks as mining operations aim to extract valuable minerals from the ocean floor. The research, published in the prestigious journal Current Biology, highlights a critical overlap between the habitats of thirty shark, ray, and chimera species and regions designated for deep-sea mining, signaling a looming conservation challenge that demands urgent attention.
Deep-sea mining targets polymetallic nodules and other metal-rich seabed resources sprawling across vast abyssal plains, particularly within areas like the Clarion-Clipperton Zone in the eastern Pacific Ocean. These zones are characterized by unique ecological communities that have evolved over millennia in stable, nutrient-poor environments. The study leverages advanced geospatial methodologies integrating global species distribution data from the International Union for Conservation of Nature (IUCN) Shark Specialist Group with territorial designations for mining under the International Seabed Authority. This approach allows for a nuanced understanding of the spatial and ecological overlap that could escalate extinction risks.
Key to this investigation was combining species-specific life history traits—such as reproductive strategies and depth preferences—with mining footprint projections. Unlike many shallow-water species, deep-sea sharks and rays often exploit a wide vertical range in the water column and engage in slow growth, late maturity, and low reproductive output. These biological characteristics magnify their vulnerability to disturbances. Of particular concern are demersal species like skates and chimaeras that deposit eggs on the seafloor, which could be directly imperiled by mining vehicles disrupting nursery habitats and sediment layers.
The research uniquely underscores how sediment plumes generated by mining could have widespread ecological consequences beyond direct physical habitat destruction. Sediment discharge into the water column can reduce water quality, smother benthic communities, and disrupt sensory cues essential for hunting and navigation among sharks and rays. These indirect but pervasive effects are predicted to impact most of the thirty overlapping species, with nearly all facing spatial interference from sediment plumes and most also at risk from direct seafloor disruption.
Among the species highlighted are globally recognized charismatic megafauna such as whale sharks and manta rays, alongside lesser-known but ecologically significant taxa including the pygmy shark and the chocolate skate. The pygmy shark (Euprotomicrus bispinatus), the world’s second smallest shark species and a member of the deep-sea fauna termed “ghost sharks,” exemplifies the diversity of vulnerable species potentially imperiled by mining. These species play vital roles in nutrient cycling, trophic dynamics, and maintaining the health of deep-sea ecosystems, where baseline ecological data remains limited.
This emerging threat coincides with a period when these species already face intense pressures from overexploitation and habitat degradation. Sharks and their relatives are categorized as the second most threatened group of vertebrates globally. Consequently, adding mining-related impacts could further strain populations, pushing some species closer to local or even global extinction. The study argues that current regulations and conservation frameworks must incorporate mining impacts explicitly to safeguard these vulnerable species.
Given the high mobility of many shark species, including those assessed, the ecological footprint of mining activities may extend well beyond immediate seabed disturbance zones. Mobile predators are likely to experience altered prey availability and altered habitat quality across their extensive ranges, potentially affecting entire marine food webs. Notably, the proximity of mining regions to biodiversity hotspots such as the Hawaiian archipelago means that indirect consequences could ripple into coastal and island ecosystems, impacting both ecological integrity and human communities reliant on healthy marine environments.
The authors emphasize the urgent need for a multi-pronged conservation strategy to mitigate mining’s impacts on deep-sea elasmobranchs and chimaeras. Central to their recommendations is adopting comprehensive environmental impact assessments that include detailed monitoring of affected species, spanning baseline studies, continuous monitoring during mining operations, and post-mining recovery assessments. Protected areas strategically placed within mining regions could serve as refuges to preserve critical habitats and maintain population connectivity.
In tandem with regulatory reforms, the study advocates for investment in scientific research to fill knowledge gaps regarding species range extensions, population dynamics, and resilience mechanisms in deep-sea communities. Ongoing efforts to document range expansions and new species occurrences are vital, as they might increase the number of species vulnerable to mining activities. Such knowledge will enable more accurate risk assessments and inform adaptive management policies responsive to emerging ecological data.
The profound ecological risks presented by deep-sea mining to sharks, rays, and chimaeras underscore the need for global governance structures to incorporate conservation science proactively. While the economic allure of mining critical minerals for technological development is strong, balancing these interests with the intrinsic value and ecosystem functions of deep-sea fauna is paramount. This study provides a critical blueprint for integrating biological risk evaluation into extraction policies and highlights the ethical imperative to protect some of Earth’s most ancient and specialized marine inhabitants.
As mining exploration advances across the abyssal plains, cross-disciplinary collaborations between oceanographers, marine biologists, policymakers, and mining companies will be essential to formulate evidence-based sustainability measures. Protecting these species is not only a matter of preserving biodiversity but also of sustaining ocean health, fisheries productivity, and cultural heritage linked to marine megafauna. The study’s findings echo a growing consensus that preserving the deep sea’s ecological integrity must be a core component of humanity’s approach to resource extraction in the 21st century.
In conclusion, this comprehensive global assessment offers a sobering perspective on the intersection of emerging industrial activities and deep-sea marine conservation. By highlighting which species are at greatest risk and illuminating pathways for mitigation, the research paves the way for informed decision-making that could reconcile resource utilization with long-term planetary stewardship. Without concerted action, the hidden depths that harbor these extraordinary species may suffer irreversible changes, compromising oceanic resilience and diversity for generations to come.
Subject of Research: Animals
Article Title: Deep-sea mining risks for sharks, rays, and chimeras
News Publication Date: 2-Oct-2025
Web References: https://www.cell.com/current-biology/fulltext/S0960-9822(25)01189-3?utm_medium=homepage
References: DOI 10.1016/j.cub.2025.09.019
Image Credits: Blue Planet Archive / Masa Ushioda
Keywords: deep-sea mining, sharks, rays, chimaeras, deep ocean biodiversity, environmental impact, conservation biology, marine ecology, abyssal plain, sediment plumes, vulnerable species, oceanography
