More Signs of Trouble

Gajić also examines sharks’ other organs. He found signs of trouble there, too. Many sharks had eaten plastic. He found fragments in their stomachs and their intestines. This may cause some of the problems and diseases in sharks.

These results are alarming. Were they isolated cases? He doesn’t think so, but he needs more samples from more sharks to be sure. One thing is certain: Each of these diseases can be traced to pollution.

Gajić studies sharks in captivity, too. 

Next Steps

Gajić has a lot of work aheadnot just in further shark studies, but in conservation, too. He has a lot of questions. Can existing laws be strengthened to protect the environment? Can awareness be raised so that people understand how human actions are affecting marine animals? What can kids do to help keep sharks healthy?

Gajić says there are many things that kids can do to help. Some might surprise you. For example: Take a look at the toothpaste you use. Some toothpastes contain microplastics. Microplastics are small plastic pieces less than five millimeters (0.2 inches) in size, which can be harmful to aquatic life. You can also help by not using disposable plastic bags or plastic drinking straws. Many of these things end up in our waterways.

He says that you can help by participating in citizen science. Is there a beach near you? Take a walk. Look at what you find thereyou may find the egg cases of some shark or skate species. Take a photo and upload it to iNaturalist. This may help researchers like him learn precisely where shark nursery grounds are.

Most of all, learn as much as you can about sharks and their environment. Then share what you know with others. The more we know about our world and how our actions can affect it, the easier it will become to help build a planet in balance.

Gajić encounters a huge jellyfish in Neum Bay.

skate egg case found on a beach in Malta

iNaturalist is a citizen science project and online network of naturalists and citizen scientists built on the concept of mapping and sharing observations of biodiversity across the globe. To learn how to use this free program, go to: