In deeper water, Gajić has come upon rough sharks and lanternsharks. He doesn’t need his camera light to see lanternsharks. They glow! The light comes from many small organs that dot their bellies and sides.
It's easier for Gajić to work with rays and skates than with sharks. He can get closer to rays, such as stingrays, as he studies them.
For Gajić, this is a dream come true. He grew up in the country of Yugoslavia. He never lived near the ocean. Yet, he was fascinated by the sea and what lived in it. He vowed to one day swim with sharks.
Gajić examines a deep-water rough shark in the lab.
Gajić knows that sharks are in trouble in the Adriatic. Pollution is causing illnesses. Plastics, pesticides, and waste poison the sea. Sewage, for example, flows into the sea. This becomes hazardous.
Outwardly, a marine animal might seem healthy. To know for certain, however, Gajić must put on his lab coat. He must examine shark organs and tissue.
Under the Microscope
Most tissue samples are taken from already-dead sharks. These come in the form of bycatch. That’s when a shark is accidentally caught in a fisher’s net and killed. When this happens, local fishers call Gajić.
In the lab, each shark is given a full x-ray and a scan. Tissue samples are then taken. From these samples, Gajić can learn a lot. In one shark, he found the disease hepatitis. That’s a disease of the liver. It might be caused by metal pollution in the water. In other sharks, he found disease in their kidneys and brains.
This sevengill shark was bycatch off the coast of Malta. This is in the Mediterranean Sea.