There are a lot of thoughts that cross your mind when you hear the word “shark.” You likely have flashbacks to all those horror movies that showed you a Great White Shark and made you scared. The last thing that probably crosses your mind is endangered. Many sharks are endangered, and much of the reason has to do with the actions of humans. There are so many repercussions that come with the declining shark populations, but not many people know about them.
Before you learn about the endangerment of sharks, there are few things that you should understand about sharks in general. Scientists believe sharks have been around for more than 400 million years, which are based on teeth and scales found in fossils. This is long before dinosaurs were on Earth. Over time, the ocean’s top predators have evolved into over 400 species that come in different sizes and colors. They also have varying diets and behavior, which is amazing for an animal that many people believe is all the same.
Sharks belong to a subclass of fish called elasmobranchii. Species in this subclass have skeletons made from cartilage and this is different from other fish which have skeletons made of bones. They also have five to seven gill slits on the side of their head. These gills are used to filter oxygen from the water so that they can breathe. Sharks come in such a wide variety of sizes that some are over 50 feet long but others are only 8 inches long.
They also have different behaviors. Throughout the world’s oceans you can find sharks and both deep and shallow waters. They migrate vast distances to feed and breed. They also give birth to their young differently. Scientists are still trying to figure out how long sharks live and they’ve only studied a fraction of the shark species on Earth. Some sharks also eat smaller fish and invertebrates but other species are known to eat larger animals, like seals, sea lions and other marine animals.
Overall, sharks are facing a battle that they’re losing. Humans are afraid of sharks, but they are not purposefully eating humans. They often believe that humans are a seal or they’re confused because they believe they’re defending themselves from a threat. Sharks are the ones that are being harmed by the actions of humans. All over the world, they are facing the threats of overfishing and climate change. 100 million sharks are killed each year to supply the demand for expensive dishes. Meanwhile, rising water temperatures in coastal developments are also contributing to shrinking shark populations.
These large predators are the top predators of the ocean and they’re critical for ensuring a balanced food web. Even though the shark populations are the ones that are shrinking, many other animal species are being distracted in the ocean by the same actions.
How Much Has the Population Declined
There’s a lot of different information that shows how much the shark population has declined globally. A lot of the information is different because there are different types of sharks and different habitats that are all affected differently by many different outcomes. In general, there’s a drastic decline in all shark populations all around the world, but this doesn’t seem serious until you learn about some of the declines in a few of the species.
Overall, a study of the Hong Kong shark fin market shows the humans killed 26 to 73 million sharks each year. This is only a comprehensive estimate of the world white shark catches and it’s usually three to four times higher than the estimate of the UN Food and Agricultural Organization. The disparity in the information is due to the fact that his organization records only shark Landings and has no data related to shark catches that are unrecorded, recorded in non-strike categories or those discarded at sea. This estimate on global shark catches from the fin market may be low because landings in Asia and discards many sharks at sea may not have been accounted for in the data.
Furthermore, 30% of the 1043 species of sharks and rays assessed have found that they are threatened or near threatened with Extinction. Then, shark numbers along the Queensland Coast have declined by more than 90% for some species in the past five decades. The University of Queensland and Griffith University researchers analyzed a shark control program data to measure changes in shark populations in a 55 year period.
The shark control program has used drum lines and nets since 1962 to try to reduce the risk of shark attack and it now spans 1760 km of the Queensland coastline. The scientists studied the number of hammerhead, white, tiger and whale sharks caught in these nuts from 1962 to 2016. The data showed the number of hammerheads and white sharks had to climb each by 92%, whale sharks by 82% and tiger sharks by 74%.
There are many different factors that lead to these large populations declines, but many of the reasons are the results of the actions of humans. Here is more information about which sharks are the most threatened by the environmental changes around them.
Which Sharks are Most Threatened
There are many different sharks globally that are threatened, but some shark populations are more threatening than others.
The great white shark is vulnerable on the Red List. Dethe spite high-profile media attention, the endangered great white shark has little known about his biology. The species has a reputation for being a ferocious maneater but humans are not their preferred prey. Humans are making these great sharks one of the most endangered species due to overfishing and collisions with shipping vessels. When people think about how many shark species are endangered, most won’t believe that the great white shark is one of them. The decline in this shark’s population is already occurring and it’s facing threats of being targeted commercially.
Another great shark that’s endangered is the basking shark. This is endangered on the red list. This is a slow-moving and harmless shark that gets his name from basking in shallow temperatures where they like to feed. They are very large, filter-feeding sharks. They are cool water, pelagic sharks and they’re migratory. They’re located all around the world and it’s only regularly seen in a few favorite coastal locations. Sadly for these sharks their fins are among the most valuable and international trade they’re over hunted.
The sand tiger shark is another vulnerable shark on the red list and it’s currently listed it as critically endangered. This shark is commonly referred to as the grey nurse shark, and it’s found mostly along sandy coastlines, Continental shelves, and submerged reefs along the coast of North and South America, South Africa, Japan and Australia. They have pointed noses and can grow up to 10.5 feet in length once they reach adulthood. They only produce two pumps for a letter and their populations in several locations have been severely depleted by commercial fishing and habitat destruction from pollution.
The last shark that’s greatly endangered is the whale shark. There are so many whale shark facts known but it’s one of the world’s most popular largest living fish. Will sharks can live up to a hundred years old and grow up to 40 feet long. They’re filter feeders that Steve Plankton through their gills for their nourishment. What are the reasons for the rapid decline in their population is due to direct fishing.
What Are the Main Threats to Sharks
Commercial fishing is the activity of catching fish and other sea food for commercial profit, mostly from Wild Fisheries. It provides a large quantity of food to many countries around the world but those who practice in the industry often pursue fish far into the Earth’s ocean under adverse conditions. Commercial fishing depletes the ocean of the main food source of most sharks. As humans catch fish for their own food, sharks are left with less choices to eat. This lack of food not only endangered sharks but it discourages breedings because the conditions are not ideal for shark pups to be healthy.
Bycatch in the fishing industry is a fissure other marine species that’s caught unintentionally while catching certain target species in a target size. Bycatch is either of a different species, the wrong sex, or is undersized or juvenile individuals of the target species. Bycatch is used for untargeted cats and other forms of animal harvesting or collecting also. Non marine species that are caught but regarded as generally undesirable are referred to as rough fish and coarse fish elsewhere, but either way this is a type of bycatch.
Sharks are also killed as a bycatch from commercial fishing. They’re often caught accidentally in fishing net designs for trapping and catching other fish. Other times, they are attracted to the panicked fish and will try to swim into the net, getting tangled and caught. They sometimes even strangle in the ropes.
This is a reason why a large portion of the sharks are endangered. There are various ways that the habitats of sharks are destroyed. Some are direct, like the cutting down of mangroves or trawling fishing nets over reefs, while others are indirect, such as pollution which affect water quality. The water quality of the sharks can become uninhabitable at times especially near coastal developments.
Coastal development has accelerated over time as the human population grows and more people decide to live on the coast. Mining and aquaculture are the other culprits of habitat degradation. The areas that are most accessible to the people are the ones most degraded so the ones most affected are terrestrial areas, freshwater habitats, estuaries, coastal areas, the inshore region and the open ocean. The sharks that live in these areas are the ones most affected by habitat degradation.
There is a lot of garbage in the sea and a lot of it is plastic. Plastic pollution is when plastic has gathered in an area and it has been negatively impacting it. Plastic pollution was first noted in the late 1960s and early 1970s and since then, the upper parts of our ocean have been filled with plastic. Many often forget that it sinks to the bottom and even all the way to the deepest parts of the ocean. Animals are finding plenty of it and they’ve started to use it as a resource. That could be a risk for ecosystem maintenance.
In time the plastic breaks into small pieces but many animals can mistake it for food and be harmed. The ingestion of plastic by sharks is understudied but many sharks that were caught between 1978 and 2000 were found with plastic in their stomach contents. Filter-feeding sharks are especially vulnerable to microplastic pollution because they get their food by moving through the water with their mouth open to consume large quantities of it.
You can participate in the conservation efforts of the ocean. The sharks of the world are quickly becoming endangered and there are many things that you can do individually that can help protect the shark species. The first step is learning as much as you can about sharks. The second step is to not use shark products. Also, choose to reduce, reuse and recycle to reduce garbage in the ocean. Lastly you can donate and volunteer with shark conservation organizations if you have spare time or money. Saving sharks can be an amazing way to save the ocean.