Sharks are among the most powerful and feared animals in the ocean, if not the world. When most people think of sharks, they experience fear rather than interest. The fact is, however, that many species of sharks are endangered or heading in that direction, so humans need to be thinking more about how to protect them than how to avoid them. (Though, avoiding them in many cases would help to protect them).

The first step in learning how to help sharks survive into the future is to learn more about them. Unfortunately, sharks are notoriously difficult to study because they travel in such large areas and getting up close and personal with them is very dangerous. Researchers have tagged many sharks with GPS trackers to learn more about their swimming habits, but that only tells part of the story.

One research team has recently published a study in the journal Frontiers in Marine Science that looked at the scars and other injuries of sharks to try to piece together more information about the life they live. Scot Anderson is one of the coauthors of the study and a Senior Researcher at the California White Shark Project. In an interview with BBC Wildlife Magazine, he said:

“The scars and wounds seen on the sharks tell us about their interactions with each other, their environment, their prey and humans. Many of the scars are distinctive enough [that] they can be easily classified.”

The study points out a number of different types of scars that can be easily identified. If you see a circular hole looking scar (or open wound) on a shark, it will almost certainly have come from a cookie cutter shark. Sharks (especially great whites) that have straight lines of scars in their skin were most likely attacked by an orca that was trying to bite into the shark to eat its liver. The list goes on with many other examples of scars that scientists already know the likely sources of. With additional study, they will undoubtedly be able to know more.

The paper specifically includes information about white sharks, saying:

“White sharks […] are one of the most studied elasmobranch species with over 21,000 instrumented tracking days, documented regional population trends, and a sequenced genome. Despite decades of dedicated research, targeted tourism, and natural history observation, significant gaps remain in our basic knowledge of their natural history. For example, no one knows the gestation period of a white shark, where they give birth, when and where they mate, and how they interact with prey, predators and each other.”

One way that this type of scar directory could help to learn more about sharks is by looking at, for example, the scars that come from mating. Many species of sharks copulate by having the male bite into the female to hold on throughout the process. This will leave distinctive scars that indicate that the female has at some point mated. Depending on how well healed the scar is, researchers could estimate how long ago the mating took place or even how many times that particular shark has mated. This could give some clues as to where the mating takes place.

Sharks live a very dangerous and violent life, so there are typically many different scars present on each individual. Having a directory like the one in this study will help researchers to paint a more complete picture of what each shark has gone through. This can be especially useful when they are able to study an individual shark over the course of multiple years. They will almost certainly get more and more scars as they age, allowing the researchers to get to know that shark much more completely.

Shark scars are able to teach us a lot about the lives of these ocean predators.

If you think that’s impressive, check out this story about a “goldmine” of lithium that was found in the U.S. that could completely change the EV battery game.