Diver captures rare footage of great white shark—in the Mediterranean

It was mid-May, roughly 50 miles offshore in the Strait of Sicily, when Derk Remmers unexpectedly encountered a massive great white shark. 

Remmers was diving nearly 200 feet below the surface on a mission to remove abandoned fishing nets. Around three minutes into the dive, a 13-foot great white emerged from the depths. 

Heart racing, Remmers scrambled to turn on his camera. The video shows the shark passing by—within around nine feet, Remmers estimated—before swimming off into opaque blue water. It’s considered to be the first underwater video of an adult male great white in the Mediterranean.

“My first thought was: ‘I need to get the camera running or no one will ever believe us.’ I felt my fingers shaking very much,” says Remmers. “It was just passing by and seemed as surprised by this encounter as we were.” 

The video is a rare document of an elusive, so-called “ghost population” of great whites that call the temperate and busy waters of the Mediterranean home. While once abundant in the region, the apex predator has declined significantly over the last century. Sharks here face the loss of their habitats, get mistakenly tangled or hooked by fishers, and compete with large commercial fishing vessels for the same fish. Yet because these sharks are elusive and rarely seen, it’s difficult to quantify exactly how many remain.

For researchers, the video of the great white is “important as a piece of the puzzle, especially because sightings like this tell us the species is still present in the area, despite the massive decrease recorded over the recent decades,” says Alessandro De Maddalena, a former professor of vertebrate zoology at the University of Milano-Bicocca and now an independent expert on great whites in the Mediterranean. 

A long history of great white sharks in the Mediterranean

A genetic study led by the University of Bologna in 2020 revealed that Mediterranean great whites are a genetically distinct population that have been isolated from other great white shark populations for around 3.2 million years, since the Pliocene period. 

By analyzing mitochondrial DNA from shark remains found over the last 200 years, researchers discovered that the region’s sharks are more closely related to Pacific populations than to those in the Atlantic. It’s unclear how the species arrived in the region, but the study suggests that white sharks from the Pacific travelled through the Atlantic and arrived in the Mediterranean via an ancient ocean passage known as the Central American seaway.

The study also noted that within the Mediterranean, great white sharks share many of the same genetics. That means that the Mediterranean group is particularly vulnerable to environmental changes and human-induced threats because they’re less capable of adapting.

The archaeological record hints at humans spotting sharks in the Mediterranean thousands of years ago. A mural at Pompeii, for instance, depicts catsharks.  But the first known record of the great whites in the Mediterranean comes from the writings of French physician Guillaume Rondelet. 

In 1554, he wrote about a shark of enormous size caught off the coast of Marseille, France with a full suit of armor in its stomach. An illustration of the shark, which Rondelet named De Lamia (a female demon of Greek mythology who consumed children) was published alongside more than 200 depictions of other aquatic animals in his marine encyclopedia Libri de piscibus marinis. 

By the 19^th century, the species was seen as a threat to humans and actively hunted in the region. Between 1872 and 1905, the Imperial Maritime Austrian government issued monetary rewards to fishermen for every great white shark caught. 

Between 1872 and 1882 alone, 21 great whites were caught, De Maddelena found through his research. During this period, one of the world’s largest sharks was also caught: a nearly 18-foot female great white shark landed off the coast of Croatia in 1906. Nicknamed Carlotta, it is currently preserved at the Natural History Museum of Trieste and is the world’s largest taxidermied great white shark.

(Great white sharks are still a mystery to us. Here's why.)

Modern threats meet modern conservation

The Mediterranean population of great white sharks is one of dozens of local marine species that are illegal to catch and sell under a United Nations treaty. Despite this, great whites are, in some cases, still illegally caught and displayed in fish markets in certain North African countries.

Globally, great white sharks are classified by the International Union for the Conservation of Nature (IUCN) as vulnerable, but the Mediterranean population is listed as critically endangered.  Researchers believe this Mediterranean population is now teetering on the brink of extinction.

But when it comes to assessing precise great white numbers in the region, there is very little data. 

Knowing exactly how many great white sharks exist here would require tagging individual sharks with GPS trackers and a large-scale photo-identification program conducted across all Mediterranean countries, both of which are currently nonexistent, explains De Maddalena. 

He’s the creator of the Italian Great White Shark Data Bank, an ongoing project cataloging every great white shark sighting in the Mediterranean, all the way back to the Middle Ages. Out of concern for a much maligned species, De Maddalena keeps his database private. He adds to it by studying preserved specimens in museums and private collections, visiting fish markets, combing through historic records and artworks, and collaborating with researchers, fishermen, divers, and private citizens. He says it currently has over 700 records.

Sightings of live animals are few and far between, and not always accurate, which further hinders white shark research in the region. Juvenile great whites can be mistaken for shortfin mako sharks, also classified as critically endangered in the region, and vice versa. 

“The information we have largely comes from scattered records of fishery interactions and surface observations, which hinders precise assessments of population structure and distribution, and limits our understanding of the species in an ecological context,” explains Carlo Cattano, a researcher at the Sicily Marine Centre of the Stazione Zoologica Anton Dohrn in Palermo, Italy.

A 2019 study estimated that the great white shark population in the region has declined by 61 percent  since the second half of the 20th century. 

“I believe there are at most a few hundred individuals left in the entire Mediterranean,” says De Maddalena. While difficult to quantify, “over the last century the decline of the species is likely greater than 90 percent,” he thinks.

There are at least 48 shark species currently recorded in the Mediterranean, and about half of them are classified by the IUCN as vulnerable, endangered, or critically endangered. 

While great whites in the region are known to eat marine mammals and large pelagic fish such as bluefin tuna, the species will also prey on smaller species of sharks and rays. Effective protections for the Mediterranean’s other shark species are therefore also essential to conserving the local great white population, says De Maddalena.

Last remaining stronghold

When he captured his great white shark video, Remmers was volunteering in the Straight of Sicily with a group of divers from non-profits—the Healthy Seas Foundation, Ghost Diving, and the Society for Documentation of Submerged Sites—to remove the abandoned nets left behind by fishing vessels, commonly called ghost nets. Divers were clearing this litter from a submerged shipwreck to prevent marine animals such as sharks, fish, and turtles from getting entangled in nets. 

This biodiverse area is believed to be a nursery for great white sharks and one of the population’s last remaining strongholds. The channel is also a key area for other shark species in the region and is located along the migratory routes for large pelagic fish like bluefin tuna, one of the primary food sources for Mediterranean great whites. “[Pregnant] females, juveniles, and adult individuals of both sexes have been recorded between Sicily, Tunisia, and Libya,” explains Cattano. 

The Eastern Adriatic, particularly the waters fringing Croatia, and the Gulf of Edremit in Turkey are also believed to be nursery areas. 

(This was the best place place on Earth to see great whites. Then they vanished.)

While the rare encounter may be a symbol of hope, much still needs to be done for the local white shark population to recover. Scientists and conservationists say laws protecting the species must be enforced in all Mediterranean countries, and they want particular fishing methods, like using longlines, banned. 

“Improving our understanding of critical habitats, identifying key hotspots, and clarifying the species’ behavioral patterns would greatly facilitate conservation efficacy and future research efforts in the region,” says Cattano.

Cattano is one of the researchers involved in the LIFE PROMETHEUS project, which is testing electromagnetic deterrent devices applied to fishing gear to reduce interactions between sharks and fishing operations.

For now, researchers are focused on learning what they can about Mediterranean great whites while they can still be found. 

“Historically, the lack of interest in shark research among the institutions responsible for marine biology studies in the area has significantly slowed the acquisition of information on these animals,” explains De Maddalena. “Fortunately, the situation has changed significantly in recent years. Let's just hope it's not too late.”