Juan Fernández Archipelago – Remote underwater mountains off Chile’s coast continue to display clear traces of fishing activity that ended more than two decades ago. Researchers documented the persistent damage during surveys conducted in 2024, highlighting how slowly deep-sea environments recover from certain human pressures. The findings underscore the long-term consequences for marine habitats that support unusually high levels of unique species.
Surveys Capture Lasting Seafloor Disruption
Teams from Chile and the United States deployed remotely operated vehicles from the Schmidt Ocean Institute’s research vessel R/V Falkor to examine four seamounts. Three of the sites lie within the Juan Fernández Archipelago, while the fourth, Solito Seamount, sits farther north. Footage from the dives revealed visible alterations to the seafloor on the archipelago sites, including tracks and disturbed sediment consistent with past net-dragging operations. The surveys took place well after the activity had stopped, allowing direct observation of conditions more than two decades later. No comparable disturbances appeared at the Solito location. These differences provided a natural contrast that strengthened the evidence linking the observed changes to earlier fishing practices.
Rich Biodiversity in a Remote Setting
The Juan Fernández Archipelago stands out for its marine endemism, with an estimated 62 percent of its reef fish species found nowhere else. Additional endemic residents include the Juan Fernández fur seal and the Juan Fernández rock lobster. Such concentrations of unique life make the area particularly sensitive to habitat disturbance. Seamounts in the region function as biodiversity hotspots by rising from the deep seafloor and creating varied conditions that support specialized communities. The persistence of physical marks on these features raises questions about how long associated species may face altered environments.
Timeline of Fishing Pressure and Policy Response
Bottom trawling targeted orange roughy and alfonsino on the Juan Fernández seamounts during the late 1990s and early 2000s. These deep-water species supported commercial catches until populations declined sharply and the fisheries collapsed. Trawling in the area then ceased. Chile introduced a nationwide permanent ban on bottom trawling across all its seamounts in 2015. The 2024 observations therefore reflect conditions well after both the local collapse and the broader prohibition took effect.
Contrasts Highlight Recovery Challenges
The Solito Seamount, which showed no signs of prior trawling, offered a reference point free of the same physical alterations. This comparison illustrated that the visible disruptions on the other sites align with the documented history of fishing rather than natural processes alone. Recovery timelines in deep-sea settings remain poorly understood, and the current evidence indicates that certain impacts can endure for at least 25 years. Further monitoring will help clarify whether gradual improvement occurs or whether additional measures are needed to support habitat restoration.
