In the vast, icy expanse of Antarctica, a silent but significant threat is unfolding beneath the waves—ship anchoring is inflicting unforeseen damage on fragile seafloor habitats. Ships from various sectors including tourism, research, and fishing frequently deploy anchors in shallow waters, leaving behind destructive footprints on biologically rich substrates. This hidden form of marine disturbance has long been underestimated, especially in the remote Antarctic region, where strict environmental regulations exist but do not comprehensively address anchoring impacts. Now, groundbreaking research led by an international team of marine scientists reveals the first video documentation of anchor and chain damage in these pristine waters, highlighting a conservation issue demanding urgent attention.
The team’s observational study, recently published in Frontiers in Conservation Science, captures a detailed picture of seafloor disturbances caused by anchor deployment and retrieval across 36 Antarctic sites during the austral summer season of 2022-23. Using underwater camera systems positioned strategically near the sea floor, midwater, and surface, researchers recorded striking evidence of mechanical scouring. The footage reveals characteristic striations and grooves etched into the ocean substrate—hallmarks of heavy chain dragging as anchors were deployed or pulled up. In many cases, these physical alterations corresponded with a marked reduction or complete absence of benthic fauna, indicating severe habitat disruption.
Analysis of these affected zones showed that species typical of Antarctic benthic ecosystems, including slow-growing sessile organisms such as sponges, were either crushed or missing entirely within the disturbed patches. This contrasts sharply with adjacent undisturbed areas where marine life thrived, suggesting a localized but profound impact. The ecological significance of this loss cannot be overstated. For example, giant volcano sponges observed near the damaged sites are believed to be some of the oldest animals on Earth, potentially surviving for up to 15,000 years. These sponges contribute critically to oceanic carbon sequestration, water filtration, and habitat complexity, all vital functions sustaining the Antarctic marine food web.
Marine ecologist Matthew Mulrennan, founder of the ocean conservation nonprofit KOLOSSAL and the study’s lead author, emphasizes the broader consequences. “The damage observed isn’t just physical scarring—it’s a disruption of entire ecological processes,” Mulrennan explains. “These sponges and other benthic species support a diversity of life, including fish, crustaceans, and even penguins and seals. When such foundational species are disturbed, the effects cascade through the ecosystem, threatening biodiversity and the resilience of Antarctic waters.”
The prevalence of ship anchoring in Antarctica is increasing alongside growing human activity and interest in this remote frontier. Despite cold temperatures and harsh conditions, at least 195 vessels—including private yachts, research ships, and fishing boats—were recorded operating at anchorable depths of up to approximately 82.5 meters during the 2022-23 season. However, the true extent of anchoring may be underreported due to ships without proper licenses or monitoring. This growing maritime footprint amplifies concerns about cumulative damage and limited recovery opportunities for the slow-recovering Antarctic benthic communities.
Marine geophysicist Dr. Sally Watson, co-author of the study, underscores the concern regarding recovery times in polar environments. “Cold-water species are characteristically slow-growing and sensitive to physical disturbances,” she notes. “In some tropical coral reef systems, anchor damage can linger visually and ecologically for over a decade. In muddy Antarctic sediments, scars made by anchors may persist even longer, given the reduced biological activity and slow sedimentation rates at these latitudes.” Such protracted recovery periods highlight the urgent need for precautionary management measures.
Complicating mitigation efforts is the lack of comprehensive data on anchoring frequency and spatial distribution in Antarctica. Without robust databases or real-time tracking of vessel anchoring behavior, it remains difficult to quantify the scale of seafloor disturbance or to prioritize areas under threat. This gap poses a fundamental challenge for policymakers tasked with balancing the protection of sensitive habitats with growing maritime operations for scientific research, tourism, and resource exploitation in the region.
Ecological consequences aside, anchoring in Antarctic waters also poses risks to critical infrastructure such as undersea cables and pipelines. Damage to these installations could have cascading effects, disrupting communication networks and power supplies that depend on reliable subsea connectivity. Such indirect impacts elevate the stakes of unregulated anchoring activities, positioning the issue as not only an environmental concern but also one of economic and strategic importance.
The documented footprint of ship anchoring in the Antarctic seabed aligns it with other recognized forms of human-induced seafloor disturbance, such as bottom trawling. According to the researchers, anchoring may be an underestimated contributor to habitat degradation on a global scale, deserving equal attention and regulatory oversight. This under-recognition stems largely from the invisible nature of the damage; unlike visible coastal impacts, anchoring scars lie beneath the waves, out of sight and consequently out of mind for many stakeholders.
Given these compelling findings, the research team advocates for enhanced monitoring and stricter regulations governing anchoring in Antarctic waters. Management strategies could include restricting anchoring to designated zones, mandating the use of environmentally sensitive mooring technologies, or implementing real-time vessel tracking systems to avoid sensitive benthic habitats. Moreover, ongoing scientific research is needed to better understand the full ecological ramifications, recovery trajectories, and potential restoration techniques suitable for cold-water benthic ecosystems.
The revelations brought forward by this first-ever video documentation of Antarctic anchoring damage form a critical call to action for ocean conservation globally. As the Antarctic region faces mounting pressures from human activity and climate change, safeguarding these ancient and complex marine habitats becomes increasingly urgent. Recognizing anchoring as a significant anthropogenic disturbance allows for targeted efforts to mitigate harm, preserving biodiversity and ecosystem services vital to planetary health.
This study not only fills a prominent knowledge gap in polar marine ecology but also serves as a stark reminder that even seemingly routine maritime operations have the potential for profound environmental impact. The fight to protect Antarctica’s seafloor ecosystems demands coordinated international attention, integrating scientific insights with governance to ensure that these remote marine wildernesses remain vibrant for generations to come.
Subject of Research: Not applicable
Article Title: Anchor and Chain Damage to Seafloor Habitats in Antarctica: First Observations
News Publication Date: 9-Jun-2025
Web References:
10.3389/fcosc.2025.1500652
Image Credits: Matt Mulrennan / KOLOSSAL
Keywords: Antarctic seafloor, ship anchoring, marine habitat damage, benthic ecosystems, underwater video evidence, ecological disturbance, slow-growing sponges, marine conservation, ocean floor impact, habitat recovery, maritime regulation, cold-water ecosystems
