NAPLES, April 23, 2026 – Researchers from the Anton Dohrn Zoological Station have reported a significant discovery in the Gulf of Naples: a large aggregation of sixgill sharks (Hexanchus griseus) in close proximity to the urban area of Naples. This finding, part of activities funded by the National Biodiversity Future Center, has been published in the journal Ecology.
Rare Sighting: Up to 5-Meter Sharks in the Gulf
The study details the observation of numerous sixgill sharks, with some individuals reaching an impressive 5 meters in length. These sharks were found associated with deep-sea bioconstructions situated between the islands of Ischia and Capri.
“Few individuals had been observed previously,” stated Simona Noè, the lead author of the study, “during dives with remotely operated vehicles coordinated by our colleague Simonepietro Canese, but we had no idea that there were so many in such a small area. They probably benefit from some protection thanks to the deep-water coral banks on the reef, which, by discouraging fishing activities, can offer a potential refuge to these specimens.”
Methodology: Non-Invasive Data Collection
To collect data, researchers utilized custom-built underwater video systems equipped with bait to attract the sharks. This non-invasive method allows for the estimation of fish abundance without harming or killing them.
Despite their imposing size, comparable to that of great white sharks, sixgill sharks are not considered a threat to humans. They typically inhabit deeper waters, with these sightings occurring at a depth of approximately 200 meters. In the Mediterranean Sea, their diet primarily consists of small fish.
Ecological Importance and Conservation Implications
Trevor Willis, the project leader, commented on the ecological role of these creatures: “These sharks could play an important role in deep-sea ecosystems, transporting nutrients from surface layers to the depths, but at the moment we still know very little.”
Simona Noè added, “Despite the species being occasionally caught as by-catch in fishing activities, reliable estimates of local population abundance are not available. The presence of such a large aggregation of these sharks near a major metropolitan area is encouraging for the ecosystem of the Gulf of Naples.”
This discovery highlights the rich biodiversity of the Gulf of Naples and underscores the importance of continued research and conservation efforts in the region’s deep-sea environments. The deep-water coral banks appear to provide a crucial sanctuary for these large marine predators, contributing to the health and balance of the marine ecosystem.
Further Research and Public Awareness
The Anton Dohrn Zoological Station plans to continue its research to better understand the behavior, population dynamics, and ecological impact of these sixgill sharks. Public awareness campaigns may also be considered to inform local communities and visitors about the presence of these magnificent creatures and their role in the marine environment, dispelling any unfounded fears.
The study’s findings contribute significantly to the understanding of deep-sea ecosystems and the conservation of marine species, particularly in areas subject to human activity and environmental pressures.
