Andrej Gajić usually dives alone. At night. In shallow, murky water. He dives under these conditions because that’s where and when he’ll find sharks. And Gajić needs to find sharks.

Gajić is more than just a diver. He’s a National Geographic Explorer and marine biologist dedicated to understanding the effects of pollution on sharks and skates and rays (flat fish closely related to sharks). To do this work, he needs to work both in a lab and in the water.

Difficult Dive

Many of Gajić's dives take place at Neum Bay on the Adriatic Sea. It’s a hotspot for sharks, rays, and skates, and a good place for him to directly observe these nocturnal creatures.

He doesn’t have to go far to reach bottom at Neum Bayonly about 30 meters (98 feet). The water here is thick with sediment and choked by colonies of planktonsmall organisms that float in the sea. To him, it feels more like swimming through yogurt than water. Visibility at this depth is zero. Gajić can’t see his hand in front of his face. He waits, letting his eyes adjust. After a few minutes, he can just make out some shapes around him.

His video camera carries a powerful light. He switches it on to cut through some of the gloom. And that’s when he sees them: smoothhound sharks. They are swimming in lazy circles near the seabed. Gajić is excited to see them but knows that he is the visitor here; this is not his home. His job is only to observe. Avoid sudden movements. Be watchful.

Gajić examines an unborn smoothound shark, searching for signs of deformities.

A lesser spotted dogfish rests on the seabed.

It’s that last piece of advice that is the most important. Most of the marine animals he encounters have no interest in people and are not likely to attack. But his presence must not cause stress to the animals. To ensure this, he pays close attention to the body language of the sharks. Do any of them seem aggressive? Is he seeing any sudden changes in movement toward him? No. The sharks appear curious, but not threatened by him. That’s good.

By the light of his camera, he begins his observations. As they swim around him, he looks closely at their jaws and teeth. He studies their gills, skin, and muscles. He’s looking for any swelling or abnormalities. He’s looking for signs of disease.

Gajić spends close to an hour in this silent world, taking notes, photographs, and shooting videos before it is time to resurface. To his eyes, the sharks appear healthy. But Gajić knows that looks can be deceiving. To truly know the health of these animals, he needs to look much deeper.

Sharks in the Adriatic

Research indicates that there are 33 species of sharks in the Adriatic Sea. Catsharks, smoothhounds, and dogfish are the most abundant. These sharks are fairly small and like to stay near the ocean floor.

In the open water, his team has encountered elegant blue sharks as well as lightning-quick mako sharks. Makos are one of the fastest marine animals, capable of bursts of speed up to 18.8 meters a second (68 kilometers or 42 miles an hour).

Another fascinating species found in the Adriatic is the thresher shark. Its body grows up to 6 meters (almost 20 feet)half of which is an elongated tail fin. Thresher sharks encircle schools of fish and then stun the prey with their tails.





Neum Bay