Shark Sightings

In deeper water, Gajić has encountered bizarre-looking rough sharks and lanternsharks. Gajić doesn’t need his powerful camera light to see lanternsharks. They glow! They are little fish, no bigger than 50 centimeters (about 20 inches) long. The light comes from many small organs called photophores, which dot their bellies and sides.

Gajić’s interactions with rays and skates are a little less problematic than with sharks. He’s able to get closer to rays, in particular. He interacts with common stingrays, eagle rays, and leopard whiprays as he studies them.

For Gajić, it is a dream come true to be among these animals. He grew up in wartorn Yugoslavia. His family moved many times when he was young, always looking for a safer and more stable place to be. He never lived anywhere near the ocean. Yet, he was fascinated by the sea and what lived in it, especially sharks. He was inspired by copies of National Geographic magazine. He vowed one day to visit some of the magnificent places he saw in the magazine and to one day swim with sharks.

researching unborn smoothhound sharks

Gajić examines a deep-water rough shark in the lab. 

Dangerous Waters

As much as he loves sharks, Gajić knows that they are in trouble in the Adriatic. Pollution is causing illnesses in many marine animals. Plastics, pesticides, heavy metals (like lead), and waste poison the sea. And in the Adriatic, war wasteammunition, grenades, bombsalso contaminates the water. The coastline along Neum is a popular vacation spot. Yet, much of the town’s sewage flows into the seasome of it is unfiltered waste. Combined, these factors make conditions for sea life hazardous.

Outwardly, a marine animal might seem healthy. To know for certain, Gajić must take off his dive suit and put on his white lab coat. In the lab, he examines shark organs and tissue through a powerful microscope. Only then can he see what’s really happening.

Under the Microscope

Gajić rarely collects samples from live sharks. If he needs a tissue sample, it is taken from an already-dead shark. These come in the form of bycatchwhen a shark is accidentally caught in a fisher’s net and killed. Many of the local fishers know that Gajić is studying sharks and their health. When a shark is caught by mistake, they contact him immediately.

In the lab, each specimen is given a full xray and a CAT scan. Tissue samples are taken. From these samples, Gajić can learn a lot. In one shark, he found an usual amount of fat in the shark’s liver. It is normal for that type of shark to have up to 50 percent of fat within the liver. This shark had far more than that. In another shark, he found the disease hepatitis. That’s an inflammation of the liver. It might be caused by high concentrations of heavy metals in the water. In other sharks, he found disease in both kidney and brain tissue. At one particular site, around 90 percent of the tissues sampled showed some evidence of disease.

This sevengill shark was bycatch off the coast of Malta in the Mediterranean Sea.