A remarkable underwater encounter in the Strait of Sicily has provided scientists with a rare glimpse of one of the Mediterranean Sea’s most elusive predators: an adult great white shark.
While diving in mid-May about 50 miles (80 kilometers) offshore to remove abandoned fishing nets, diver Derk Remmers unexpectedly came face-to-face with a 13-foot (4-meter) great white shark nearly 200 feet (60 meters) below the surface.
The encounter is believed to be the first underwater video ever recorded of an adult male great white shark in the Mediterranean Sea.
An Unexpected Encounter
Remmers was participating in a conservation mission to remove ghost nets—discarded fishing nets that continue trapping marine life long after being abandoned.
About three minutes into the dive, a massive shark slowly emerged from the blue.
His first reaction wasn’t fear.
“My first thought was: ‘I need to get the camera running or no one will ever believe us,'” Remmers said.
The shark calmly swam within roughly 9 feet (3 meters) of the divers before disappearing back into the deep water.
According to Remmers, the shark appeared just as surprised by the encounter as the divers were.
A “Ghost Population”
Scientists describe Mediterranean great white sharks as a “ghost population.”
Although they once occurred throughout the Mediterranean, sightings today are extremely rare.
Researchers know the sharks still exist, but because they are so elusive, determining exactly how many remain has become incredibly difficult.
The new footage is valuable because it confirms that adult great whites are still present in one of their last known strongholds.
A Unique Population
Research published in 2020 revealed something remarkable.
Mediterranean great white sharks are genetically distinct from great white populations elsewhere in the world.
Scientists estimate they have been isolated for about 3.2 million years, dating back to the Pliocene Epoch.
Genetic analysis suggests these sharks are actually more closely related to Pacific Ocean populations than Atlantic ones, likely descending from sharks that entered the Mediterranean through the ancient Central American Seaway before it closed millions of years ago.
However, because today’s Mediterranean population shares relatively little genetic diversity, it is especially vulnerable to disease, environmental change, and human impacts.
A Long History
Humans have known about Mediterranean great white sharks for centuries.
The first detailed written description dates back to 1554, when French physician Guillaume Rondelet described an enormous shark caught near Marseille, France. According to his account, the shark even contained a full suit of armor in its stomach.
During the late 1800s, governments actively encouraged fishermen to kill great whites.
Between 1872 and 1905, the Austro-Hungarian government paid rewards for every shark caught.
One of the largest known specimens, an almost 18-foot (5.5-meter) female nicknamed Carlotta, was caught off Croatia in 1906. She remains preserved at the Natural History Museum in Trieste, Italy.
Why They’re Disappearing
Today, Mediterranean great white sharks face numerous threats, including:
- Overfishing
- Accidental capture in fishing gear (bycatch)
- Illegal fishing despite legal protections
- Habitat degradation
- Declining prey populations
- Entanglement in abandoned fishing nets
The Mediterranean population is now classified as Critically Endangered, even though the species is listed globally as Vulnerable.
Researchers estimate that the Mediterranean population has declined by approximately:
- 61% since the second half of the 20th century.
- More than 90% over the past century.
Some experts believe only a few hundred individuals remain throughout the entire Mediterranean Sea.
Why Counting Them Is So Difficult
Unlike some shark populations, Mediterranean great whites are extremely difficult to monitor.
Scientists currently lack:
- large-scale satellite tagging programs,
- coordinated photo-identification databases,
- comprehensive surveys across Mediterranean countries.
Many sightings are also misidentified because juvenile great whites closely resemble shortfin mako sharks, another critically endangered Mediterranean species.
To improve knowledge, researchers maintain extensive databases of historical sightings, museum specimens, fishing records, artwork, and eyewitness reports. One database now contains more than 700 records, some dating back to the Middle Ages.
The Strait of Sicily: A Vital Refuge
The shark filmed by Remmers appeared in what scientists believe is one of the species’ last major refuges.
The Strait of Sicily, between Sicily, Tunisia, and Libya, is thought to serve as:
- a nursery area,
- an important migration corridor,
- a feeding ground rich in Atlantic bluefin tuna, one of the great white’s preferred prey.
Other suspected nursery areas include:
- the eastern Adriatic Sea near Croatia,
- Turkey’s Gulf of Edremit.
Conservation Efforts
Several conservation projects are working to improve the species’ chances of survival.
Current efforts include:
- removing ghost fishing nets,
- strengthening enforcement of existing fishing bans,
- identifying important shark habitats,
- testing electromagnetic deterrent devices on fishing gear to reduce accidental shark captures,
- improving scientific monitoring and research.
Researchers stress that stronger cooperation among Mediterranean nations will be essential if this unique shark population is to recover.
A Symbol of Hope
Although seeing an adult Mediterranean great white is extraordinarily rare, this encounter offers hope that the population still survives.
For scientists, every confirmed sighting helps fill another piece of the puzzle about one of the world’s least understood shark populations. At the same time, the footage serves as a reminder that protecting these ancient apex predators will require continued research, stricter conservation measures, and international collaboration before it is too late.