Sharks are in Trouble
Sharks have long been portrayed as "monsters of the sea" and "man-eating machines". A lot of people are scared of sharks, and think the ocean would be a safer place without sharks. That image of sharks is just fiction. Those monster sharks are created in studios and exist only in movies.
The fact is, humans are not sharks' preferred food. Sometimes it is not clear to sharks whether the silhouette on the surface of the sea is human or prey.
Sharks are not really a threat to humans. There are 548 known species of sharks, but only 13 species have a confirmed record of biting humans 10 or more times.1 In 2020, 129 shark-human interactions were investigated by ISAF, with 57 unprovoked shark bites and 39 provoked bites on humans confirmed. Ten were fatal.
Worldwide, an estimated 10.0 million cancer deaths occurred in 2020.2 Approximately 1.35 million people die each year as a result of road traffic crashes.3 The WHO estimates that 438,000 people died because of malaria in 2015.4 More than 400,000 people die from homicide each year5, and rabies causes approximately 59,000 deaths worldwide annually.6 Smartphones are more dangerous than sharks; the number of selfie deaths was 98 in 2016 and 93 in 2017.7
Sharks are not a huge threat to humans, whereas human fishing activities have threatened the survival of sharks greatly. In just half a century (1970 to 2020), the abundance of oceanic sharks globally declined by 71.1%8
A third of the world's sharks and rays are threatened with extinction according to the evaluation of the IUCN Red List of Threatened Species Shark Specialist Group in 2020.9
The greatest threats to sharks are overfishing and bycatch. Fishermen sometimes catch and discard animals they do not want, cannot sell, or are not allowed to keep. This is called bycatch. Bycatch can be fish, but also includes other animals such as dolphins, whales, sea turtles, and seabirds.
Unlike bony fishes, sharks reproduce very slowly. Bony fishes can lay thousands of eggs at a time, several times a year. Sharks lay few eggs and have long gestation periods. Sharks also need years to sexually mature. For example, spiny dogfish shark pups grow in their mother's belly for 24 months before birth. A female thresher shark gives birth to two pups every year and can only give birth to about 40 pups over her lifetime. Greenland sharks live up to 400 years and do not start having babies until they are 150 years old. With such a slow birth rate and high fishing rates, more sharks are being killed than are being born.
Large predatory marine fishes like tuna, marlin, and sharks often have high levels of mercury and other dangerous toxins in their meat. These often make them unfit for human consumption, particularly for pregnant women. Some toxins found in sharks include mercury, arsenic, and BMAA, a neurotoxin that is associated with Alzheimer's disease.
Now that you have learned more, it's time to take some action and help save sharks!
Sources Cited
1 - Shark Attacks
2 - Cancer
3 - Global Road Traffic Deaths
4 - Malaria
5 - Homicide
6 - Rabies
7 - Selfie Deaths
8 - Global Decline in Oceanic Sharks and Rays
9 - IUCN Red List