The presence of Great white shark in the Spanish Mediterranean It's not an urban legend or a movie plot device, but a scientifically documented, albeit extraordinarily rare, fact. A new study by the Spanish Institute of Oceanography (IEO-CSIC) and the University of Cádiz puts this species back on the map of our waters, but with important nuances to understand what is really happening.
Far from sensationalism, the data shows a much more discreet scenario: The great predator continues to sporadically cross the western Mediterraneanwith very few confirmed records in over a century and a half. The latest case, a juvenile specimen accidentally caught off the coast of Alicante in April 2023, offers valuable clues about the distribution and status of this vulnerable population.
A two-meter juvenile off the coast of Alicante
On April 20, 2023, some fishermen who were working in the waters of the MediterraneanIn Spain's Exclusive Economic Zone, a shark was accidentally caught after becoming entangled in their fishing gear. The incident occurred near Cape Nao and Cape San Antonio, approximately 11 nautical miles off the coast of Dénia and Xàbia (Alicante), in an area of submarine canyons and deep waters relatively close to shore.
The animal, which was already dead when it was hoisted aboard, measured around 2,1 meters total length and it weighed between 80 and 90 kilos, indicating that it was a juvenile. The great white shark is considered an adult at around 4,5 meters and can exceed six and a half meters in length, with a lifespan of around 70 years in the Mediterranean.
After confirming that it was not a commercially valuable species, the fishermen took photographs and videos of the specimen and returned it to the sea. That seemingly minor step proved crucial: thanks to the previous collaboration between the fishing sector and the scientists of the IEOThe images and samples were able to reach the laboratory to be analyzed in detail.
A genetic study was conducted on the animal's tissues at the IEO-CSIC. Mitochondrial DNA sequencing confirmed beyond any doubt that it was Carcharodon carcharias, the great white shark. This verification makes the episode one of the few fully confirmed records in Spanish waters in recent decades.
An exceptional record within a history spanning more than 160 years
The finding has not been studied as an isolated case. The team from the IEO-CSIC and the University of Cádiz carried out a thorough review of historical records of great white shark in Spanish waters, covering from the mid-19th century (1862) to 2023. In that period, between 62 and 66 documented records have been compiled, according to the criteria applied to direct and indirect evidence.
That set of records includes everything: accidental captures like the one in 2023, confirmed direct sightings (such as the one observed in 2018 near Cabrera National Park in the Balearic Islands) and indirect signs, for example, bite marks on stranded sea turtles that can only be attributed to large predators such as the great white shark or the tiger shark.
The review also includes unique episodes, such as the capture of a great white shark of more than five meters near Bolonia beach, in Tarifa (Strait of Gibraltar), during tuna fishing operations in 2015. With all these pieces, the researchers draw a clear patternThe species maintains a persistent but extremely infrequent presence in the Spanish Mediterranean.
The study, published in the scientific journal Acta Ichthyologica et PiscatoriaIt highlights that the low detectability of the great white shark means that some of its presence goes unnoticed. Even so, There is no solid data to suggest that the Mediterranean population is recovering.Rather, the authors point out that it is now detected better thanks to increased communication and collaboration protocols with the fishing sector.
In some areas, the numbers are even going in the opposite direction. Recent research indicates that, between 1980 and 2016, the abundance of great white sharks in Balearic waters may have fallen by more than one percent. 70%-73%In that context, each new verified record has a particularly high value for monitoring and conserving the species.
A sea of rare records: attacks, sightings and bites on turtles
One of the issues that arouses the most public interest is maritime safety. The historical review carried out by the scientific team shows that, in more than 160 years of records in Spanish watersIncidents involving people have been remarkably rare.
The researchers have only been able to confirm two attacks Documented incidents during this period include one in 1862 in Málaga, in which a swimmer died; and another in the 1980s, when a shark bit a surfer's board in Tarifa, causing serious injuries. No further confirmed cases have been found on our coasts since then.
If these two incidents are compared with the time elapsed and the intensity of use of Spanish beaches, The experts' conclusion is clearThe great white shark does not pose a significant risk to swimmers or to normal recreational activities on the coast.
Much of the evidence of their presence has nothing to do with humans, but with other marine animals. The historical review identifies bites on sea turtlesThis is especially true for the loggerhead turtle, whose shell can only be pierced by the teeth of large predators such as the great white shark or the tiger shark. These indirect clues help to complete the map of the species' movements in the absence of direct sightings.
Furthermore, many of these observations coincide temporally with the seasonal migration of Atlantic bluefin tuna towards the Mediterranean to reproduce. This overlap supports the idea that the movements of the great white shark are closely linked to the availability of prey, and that Spanish waters often act more as a transit corridor than as a stable residential area.
Juveniles in Spanish waters: clues about possible breeding areas?
The fact that the specimen captured in 2023 was a juvenile of about two meters This adds a special scientific interest to the case. In species listed as vulnerable, the detection of young individuals provides valuable information about the demographic structure and on whether recruitment of new generations is taking place.
In the Mediterranean, the lack of records of newborns and juveniles has been a constant. Traditionally, they have been identified as potential breeding areas the Strait of Sicily and the Gulf of Gabès (east of Tunisia). More recently, the appearance of several newborns since 2008 has led to the proposal of Edremit Bay, in the northeast Aegean Sea, as another potential hotspot for the Mediterranean great white shark.
The presence of a juvenile in the Spanish Mediterranean opens up two main hypotheses: that it is an individual born in those breeding grounds of the central and eastern Mediterranean that it has migrated westward, or that there are breeding areas closer to the Spanish coast that have not yet been formally identified.
The authors of the study urge caution. Based on current data, it cannot be stated that there are breeding areas off the coast of Spain.To answer that question rigorously would require continuous monitoring programs, tagging and telemetry, as well as population genetics and environmental DNA techniques that allow tracking the presence of the species without needing to see it.
At the same time, scientists point out that the Mediterranean Sea today differs greatly from what it was in recent geological times. During the Pleistocene, the great white shark was supposedly much more common in this sea and shared its habitat with large prey species that are now extinct. The modern scenario is rather poor in comparison, which complicates the survival of such demanding superpredators.
A highly mobile predator in an increasingly pressured sea
The great white shark is a highly mobile and mostly pelagic animalThat is, it spends much of its time in the open ocean, far from the coast. It is not a species that frequents the shore regularly, and in fact, researchers point out that these sharks avoid very shallow waters due to the risk of becoming stranded.
That a specimen appears in waters relatively close to the coast, as in the case of the capture off the coast of Alicante province, is usually interpreted more as a anomaly in their normal behavior which is a pattern. Scientists point out that these approaches may be due to disorientation, illness, or specific movements following schools of prey.
At the same time, the Mediterranean is a closed sea subject to a strong human pressureIntensive fishing, maritime traffic, pollution, loss of coastal habitats, and the effects of climate change all impact food availability and the ecosystem's capacity to support healthy populations of large predators.
In this context, the link between the great white shark and the Atlantic bluefin tuna This takes on particular significance. The spatial and temporal overlap between tuna migration to the Mediterranean and many great white shark sightings suggests a direct relationship. In fact, studies point to a worrying synchronicity: the historical decline of bluefin tuna in certain regions goes hand in hand with the disappearance of the great white shark in those same areas.
For researchers, all of this reinforces the idea that it is not enough to focus on a single predator. The conservation of the great white shark also depends on the good management of its prey and the ecosystems that support them.It's just one more piece of a much larger ecological puzzle.
From alarm to data: what science tells us about risks and conservation
Popular imagination, fueled by decades of films and sensational headlines, has constructed the image of the great white shark as a constant threat. However, data gathered by the IEO-CSIC and the University of Cádiz point in another direction: We are faced with an extraordinarily rare animal in our waters, whose relationship with people is minimal and almost always non-existent.
That doesn't mean the risk is literally zero, but it does mean that The probability of a dangerous encounter on the Spanish coast is extremely low when compared to other common risks at sea, such as currents, waves crashing, or even human recklessness.
Beyond safety, the study emphasizes the ecological role of this species. As a top predator, the great white shark acts as regulator of food chainsinfluencing the behavior and distribution of their prey and contributing to the stability of the entire marine ecosystem. Their presence, even if minimal, is an indicator of the ocean's health.
For all these reasons, the researchers are calling for a strengthening of the monitoring and conservation programs of the great white shark in the Mediterranean. They propose combining classic tools (collaboration with the fishing sector, records of stranded fauna, direct observations) with more recent techniques such as genetics, environmental DNA and telemetry to better track their movements.
The story of the great white shark in the Spanish Mediterranean, as depicted by science, is that of a a superpredator that we barely see but that is still presentThis is linked to the migrations of large prey and a sea that has changed rapidly. Far from a “return of the monster,” the data points to a vulnerable, scarce species that is key to the balance of the ecosystem, and whose protection depends largely on our continued accumulation of reliable information about its location, its movements, and its needs to maintain a presence in our waters, however discreetly and fleetingly.