Scientists are warning that great white sharks may be quietly establishing a breeding population in the Mediterranean, based on a new analysis of 20th and 21st century records that reveals emerging offshore hotspots. Lead researchers behind a 2024 peer-reviewed study, identified by the DOI 10.3390/jmse13091704, argue that the pattern of sightings signals a shift away from historic coastal haunts and toward deeper central basins. I set out to examine what that evidence really shows, how strong the breeding claim is, and what it could mean for both marine ecosystems and people who swim and sail these waters.
Evidence of Changing Distribution
The new peer-reviewed analysis of Mediterranean great white sharks compiles and maps validated records from across the 20th and 21st centuries, using what the authors describe as a systematic review of historical archives, fisheries data and modern reports. By plotting these vetted sightings and captures, the team behind the Journal of Marine Science and Engineering study found that traditional coastal hotspots have faded, while activity has shifted toward the offshore central Mediterranean. According to their mapping, the southern Strait of Sicily and the adjacent Gulf of Gabès now stand out as key concentration zones in recent decades.
This geographic pivot matters because the Strait of Sicily and Gulf of Gabès sit at the crossroads of several Mediterranean sub-basins, creating a productive corridor for large predators. The study’s authors argue that the clustering of modern records in this offshore area, contrasted with the relative quiet in former coastal strongholds, suggests a broader redistribution of the regional population. Their work supports warnings highlighted in recent coverage that scientists now see the central Mediterranean as a potential core area for the species, rather than a marginal outpost, and that this shift may be tied to where great whites are feeding and possibly reproducing.
Key Sightings Supporting Breeding Hypothesis
The breeding hypothesis does not rest on maps alone. One of the most cited pieces of evidence is a gravid female documented in Tunisian waters and described in detail by Saïdi and colleagues. That case, preserved in the canonical Cybium paper, records a large female great white whose reproductive state was confirmed through examination of her embryos, providing rare, specimen-level proof that pregnant animals use the southern central Mediterranean. For researchers, a gravid female in this area is a strong hint that the region is not just a transit route but part of the species’ reproductive range.
A second pillar of the argument comes from a peer-reviewed case report of a young-of-the-year shark off the Croatian coast that had initially been misidentified as another species. The authors of that study, published in an open-access fisheries journal, used morphological details to correct the record and confirm that the animal was in fact a great white, as set out in the Croatian case report. One expert quoted in more recent coverage explained that the presence of such very young individuals, combined with a gravid female in nearby waters, implies that at least some reproduction is occurring within the basin rather than being supplied entirely by migrants from the Atlantic.
Why This Matters for Ecosystems and Humans
Great white sharks sit near the top of the food web, so any shift in where they congregate can ripple through Mediterranean ecosystems. Researchers involved in the central Mediterranean analysis argue that changes in predator distribution may reflect underlying shifts in prey, fishing pressure or environmental conditions, with potential consequences for biodiversity in the Strait of Sicily and Gulf of Gabès. Because the species is generally treated as protected or threatened in regional management frameworks, evidence that it may be breeding locally strengthens the case for safeguarding critical habitats and limiting bycatch in high-use areas.
There is also a human dimension, particularly in coastal zones popular with British holidaymakers. Recent reporting aimed at general audiences has emphasized that British tourists increasingly flock to Mediterranean destinations where these sharks have been recorded, raising concerns about risk perception even though documented attacks remain rare. One tabloid framed the new science as a warning for travelers, while a separate piece in The Express highlighted the possibility of breeding in areas frequented by UK visitors. For wider context, National Geographic’s coverage of giant great white sharks in the Mediterranean has long pointed out that some of the largest individuals on record have appeared here, underscoring that this is not a benign, small-bodied population but one that includes full-sized apex predators.
Scientific Methods and Challenges
The backbone of the new warnings is a peer-reviewed, data-compiled analysis that set strict rules for what counted as a valid Mediterranean great white record. The authors behind the central Mediterranean mapping study filtered out anecdotal or poorly documented sightings, relying instead on photographs, specimens, fisheries logbooks and other verifiable sources. By segmenting records into 20th and 21st century bins and overlaying them on geographic grids, they could compare historical coastal hotspots with modern offshore clusters, which in turn fed their projection that the southern Strait of Sicily and Gulf of Gabès might function as a core area and possible breeding zone.
Yet the science is complicated by misidentification risks, as the Croatian young-of-the-year case makes clear. That shark was first logged as a different lamnid species before a detailed re-examination, published in the peer-reviewed Croatian report, corrected it to Carcharodon carcharias. Such errors can inflate or deflate apparent juvenile numbers, which matters when scientists are trying to infer breeding from age structure. The lead authors of the distribution study, and experts quoted in follow-up news coverage, stress that while the pattern of gravid females and very young sharks supports a breeding hypothesis, firm confirmation of specific nurseries in the Mediterranean is still thin and will require more targeted fieldwork.
Conservation Responses and Future Monitoring
Warnings that great white sharks may be breeding in the Mediterranean are already feeding into calls for stronger conservation measures. The central Mediterranean study’s identification of the Strait of Sicily and Gulf of Gabès as hotspots has prompted some researchers to argue for spatial protections or gear restrictions in those zones, particularly where fisheries overlap with shark movements. In consumer-facing coverage, a Metro report on the potential breeding grounds quoted a conservation expert who urged authorities to treat these areas as high priority for monitoring and to work with fishers on bycatch reduction, while acknowledging that enforcement and political will remain uncertain.
Policy responses are still in early stages, and long-term trends are hard to pin down because reliable baselines are scarce. Some national and regional plans already list great whites as protected, but the new distribution data give managers a more precise map of where interventions might matter most. A conservation specialist cited by The Express argued that even the possibility of local breeding should be treated as a reason to invest in better reporting networks, standardized data collection and cooperative research cruises in the Strait of Sicily and Gulf of Gabès. I see that as a pragmatic stance: act on the best available evidence, while building the datasets needed to refine or revise the picture over time.
What Remains Uncertain
Despite the strong interest generated by these findings, several key questions remain unresolved. The presence of a gravid female documented by Saïdi and colleagues and the confirmed young-of-the-year off Croatia make a compelling case that reproduction is occurring somewhere in the region, but they do not yet pinpoint exact breeding sites or prove that the Mediterranean hosts a fully self-sustaining population. The authors of the canonical gravid-female report and the Croatian juvenile case study both stress that their specimens are snapshots rather than a complete demographic survey, and subsequent syntheses caution that some historical records remain disputed or too vague to map confidently.
Genetic work could help answer whether Mediterranean great whites form a distinct subpopulation or are regularly replenished by immigrants from the Atlantic, but such studies are still limited, and several recent news pieces explicitly describe this line of evidence as a gap. The distribution analysis in the Journal of Marine Science and Engineering highlights the need for coordinated tagging, tissue sampling and long-term monitoring to test whether the central Mediterranean hotspots function as nurseries, feeding grounds or both. For now, scientists are clear on one point: the best available records indicate that great white sharks are using the Mediterranean in more complex ways than previously recognized, and keeping track of that evolving pattern will be essential for both conservation planning and honest communication with the millions of people who share these waters.
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*This article was researched with the help of AI, with human editors creating the final content.
