It’s a sunny day on the beach. A boy and his dog are playing fetch in the water, but the dog has disappeared. The boy calls for the dog at the water’s edge. Duunnn dunn… duuuuuunnn duun… Suddenly there’s a commotion of splashing and a gray shape cuts the surface of the water ahead.
A fin in a net?
It’s not the dog or people who are in trouble here. It’s the shark.
What is bycatch?
You likely wouldn’t spot a shark freshly caught in a net from the beach, but this unintended entrapment or bycatch is a very real threat throughout our oceans. Bycatch is when non-target marine animals are hooked or netted inadvertently by fishermen targeting other species.
Shark bycatch is common in longline fisheries for large pelagic — or open-ocean — fish like tuna and swordfish. These boats set out lines up to 45 miles long rigged with thousands of baited hooks. Other fisheries that depend on large nets also catch sharks unintentionally.
Why is bycatch scary?
Surveys of some pelagic longline fisheries have found sharks making up at least 25% of total catch. Unfortunately, this is likely an underestimate because of underreporting of bycatch.
Sharks lucky enough to be unhooked and thrown back have a high mortality rate because of associated injuries and stress from the catch. All too frequently, though, fishermen will retain bycaught sharks to sell their valuable fins and meat.
These catches add up: humans kill over 80 million sharks each year. As a result, 30% of all shark and ray species are now threatened with extinction. And bycatch is only one major threat to these ocean dwellers. Other threats include overfishing to meet demand for shark fins and meat, habitat destruction and loss of prey.
So, are sharks dangerous?
Sharks are not generally dangerous to humans. There is an estimated one in over 11 million chance of a shark attack occurring. In fact, ocean-goers are over 1,800 times more likely to drown than suffer a shark bite. In 2023, there were 69 unprovoked shark attacks globally, with 36 occurring in the United States. Only 14 of those 69 attacks were fatal, including two fatalities in the U.S. Although these fatalities are tragic, they are incredibly rare.
When unprovoked attacks or bites do happen, it’s likely from a confused or curious shark. Sharks are known to use their mouths to investigate unfamiliar objects. Apex predator sharks, like great whites (Carcharodon carcharias), tiger (Galeocerdo cuvier) and bull sharks (Carcharhinus leucas) — the top three species involved in shark attacks — may mistake a splashing human as prey.
Still, it is important to respect sharks as wild and powerful animals. It’s always good to maintain your distance. You can also stay safe in the water by:
- Avoiding swimming near fishing activity and swooping seabirds.
- Avoiding steep drop-offs in the water and areas between sandbars, as sharks favor such spots.
- Swimming with others. Sharks are less likely to approach a group.
- Wearing dull swimwear and taking off jewelry before swimming. Shiny objects can mimic a fish’s scales and make you look like food.
Why are sharks important for our oceans?
Sharks are indicators of our ocean’s health and serve several ecological roles. Apex predators at the top of the food chain help maintain healthy populations of the species below them. Some sharks are both predator and prey, and others are scavengers, helping keep our oceans free of rotting carcasses. By changing the feeding patterns of their prey, sharks also help to conserve coral reefs and seagrass beds, both of which are important, biodiverse marine habitats.
There are also filter-feeding sharks that eat plankton. Whale sharks (Rhincodon typus) are a well-known type of filter-feeding shark and are the largest known living fish species. (Yes, sharks are fish, not mammals!)
There is only one known omnivorous shark species or known to eat both plants and meat. Bonnethead sharks (Sphyrna tiburo) primarily eat crustaceans, but will also eat clams, octopus, small fish and seagrass.
How you can help sharks!
"Jaws” is just one example of how movies have falsely made sharks villains. It’s up to all of us to change the narrative and show that sharks are not what we should be most afraid of in the ocean. Here are three ways to help sharks:
- Share the real shark story. Help spread the word about the role sharks play in our oceans. Use your platforms to talk about how much healthy oceans depend on sharks.
- Eat sustainable seafood. Ask questions about the food you purchase and look for brands or labels indicating your food was caught sustainably. Monterey Bay Aquarium Seafood Watch is a trustworthy certification source.
- Decrease the demand. Avoid eating shark meat or shark fin soup. Read supplement and personal care ingredient labels for chondroitin, which may be made from shark cartilage, and squalene or squalane, which may be made from shark liver oil. Choose products made from plant-based or synthetic ingredients instead.
Join Defenders all October for twists on classic horror movies. Learn about some not-so-spooky animals and the real threats they face!
Author
Allison Cook
Areas of Expertise: Communications, writing for the blog and website
Allison joined Defenders of Wildlife in 2023 after working for Smithsonian's National Zoo and Conservation
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