Shark scales, or dentricles, are roughened and will scrape if felt to wrong way, much like sandpaper. The true purpose for this is unknown, although it is thought the shape increases streamlined properties. Sharks have two pairs of fins and four singular fins, all of which are used for swimming or balance. The rear pelvic fins in males are lengthened to aid in reproduction. The oil in the shark’s liver adds buoyancy, due to the lack of a swim bladder. The gills are protected by gill arches and slits, and most sharks must swim continuously to keep oxygenated water flowing over their gills. Some sharks, such as the wobbegong or nurse sharks, have developed the ability to lie on the ocean floor and forcefully pump water over their gills. The body …show more content…
shape of a shark is dependent of its habitat, relative water temperature, and diet. Sharks with more sleek bodies and short, powerful tails are more often oceanic and fast, while sharks with a flattened design are usually bottom-dwelling and slow-moving. There are exceptions such as the whale shark, which is both oceanic and slow-moving, but most sharks are within these classifications. Sharks also possess the ampullae of Lorenzini, which is a line of electro-sensitive pores along the shark’s midline. These allow the shark to detect minute electrical signals given off by prey, and are often used to find food under sand or coral ledges. Sharks, unlike most fish, lack a bony skeleton and a swim bladder. To compensate for these, they have a liver filled with oils to provide extra buoyancy and a cartilaginous skeleton. Due to this lightweight build, sharks are arguably stronger and more flexible than bony fish. However, many sharks are forced to swim their entire lives to avoid sinking. This, inevitably, can make reproduction difficult, both in finding another shark and in breeding. The majority of pelagic sharks are viviparous, and only produce 2-3 pups annually. Coupled with maturity rates of about 10 years, many sharks are incredibly slow to reproduce. Sharks have been extensively hunted, for sport and for food, for hundreds of years.
Many species are endangered or at risk of becoming so due to this. Smaller sharks, such as the dogfish, have less issue of this due to the lack of fishing and industry they pose. Larger sharks are also often able to avoid population drops and fishing, simply due to the cost of catching one outweighing the benefits. The sharks that are hunted are common species such as great whites, tiger sharks, and other oceanic breeds that are easily found. When a shark is caught, it is either killed for its teeth and scales or for the purpose of finning. If the shark is finned, the pectoral, dorsal, and often caudal fins are removed and the shark, usually still alive, is thrown back into the water. Unable to swim and hunt, it soon dies.
One way to lessen the effect of finning and sport hunting on shark populations is to flood the market with artificial yet genetically real fins, such as has been done with rhinoceros horns. If the price drops, the amount of sharks killed annually will fall with it. Doing this will also help return ecosystems back to the way they were before the top predators had been hunted out of the area. This will aid in managing fish populations as well, especially those not fished commercially such as jacks and
grouper. Bull sharks are one of the more aggressive species, listed third in the amount of attacks per year. This willingness to attack, coupled with the ability to survive in freshwater for extended periods, makes this species potentially more dangerous than great whites or tiger sharks, the top two in attacks. They utilize osmosis to swim upriver, and have been found over 2,000 miles inland. Their high attack rate is due to increased levels of testosterone in their blood. These factors, when combined with size and higher population, create the possibility for far more attacks than have already happened. Most sharks, despite general belief, probably dislike the taste of human as a meal. Many bites are inflicted on surfers, which the shark mistakes for a seal or sea lion. Once they realize that it isn’t, the victim is usually just let go of. To the shark, it was simply a test bite to determine what exactly it was biting into. Unfortunately for the surfer, a single test bite can cause serious damage. Interactions like this are almost always accidental, however, and while safety measures should always be taken the shark itself is not at fault.
So why do we need sharks? Well, Sharks help keep the ocean healthy and clean for over 450 million years. They also help remove half of the worlds green house gases and produces oxygen more than all of the rainforest's combined! Sharks are just as important as all the trees in the world because they have one thing in common, provide us with oxygen. Without the sharks help we wouldn't be able to get rid as much of the greenhouse gases as we want to, which means global warming would have a lower rate of happening faster. Most importantly they provide us with food. How? They would usually eat the old, sick or slower fish in the population of the ocean to the right size so the prey species don't cause harm to ecosystem by becoming to populated. They are also at the top of the food web. If all the sharks went extinct the entire food web would collapse causing many other species of fish to disappear. So instead of killing the sharks, we could lure them away to somewhere else. As they have a huge impact to the environment.
Shark nets have been implemented in locations across the world in response to shark sightings and attacks. Nets are submerged beneath the surface of the water, roughly 200 metres from the shoreline. The meshing is designed to be large to capture sharks, leaving them to struggle before eventually drowning under the weight of their own body. The meshing allows small fish to pass through, however captures larger fish and marine species. Shark nets provide no discrimination between common, vulnerable and endangered species, resulting in a high mortality rate for a variety of marine wildlife.
Every year, there are about 100 million Sharks killed, ultimately for its commercial success. Their fins are used as the main ingredient for a dish so-called Shark soup. However, many are unaware of the actual importance of Sharks' existence on Earth. They do a number of things to control and balance aquatic life down below, which in return affects how we live on the surface. Sharks have existed in our world for over 400 million years, if they were to suddenly disappear for industrial purposes, much problems will be encountered throughout the world. We must preserve the lives of Sharks, for many reasons most importantly that shark hunting is morally wrong, it may provide economic failure in a given time, and it may serve a critical unbalance of a healthy environmental state.
But occasionally the younger sharks are preyed on by bigger sharks that do not necessarily have to be Bull sharks they can be become prey to any larger species of shark and occasionally a crocodile. However there are parasites like Pandarus sinuatus, and Periscopus dentatus that use the surface of the shark’s skin and use it to survive (Curtis). Though that does not in anyway decrease or increase the economic uses for the bull shark, its effects on the environment, or level of danger to humans. In certain places around the world the amount of bull sharks is decreasing slightly, because sharks can be harvested to make fish food, for their meat, for oils, and their fins for shark fin soup, or in asia their skin can be used to make “good leather” (“Bullshark”; Curtis). Even though their numbers are thought to be decreasing according to the International Shark Attack Files, otherwise known as the ISAF, has reported that there have been at least 70 reported unprovoked attacks on humans of which 17 were fatal, but that is only the known number of the reported attacks by bull sharks there most likely have been many more attacks that went unreported (“Bullshark”; Curtis). They are known for being one of “the most dangerous sharks in the world” because they along side the tiger shark,and great white they are the most common sharks to attack a human
The Great Shark debate – to cull or not to cull, has been at the forefront of the minds of conservationists, as well as the general population for many decades now. The opinions of everyone are divided, according to their personal experiences, and views on what is right and wrong for the environment.
One of the governments main reasons for culling the sharks is because they are coming in too close to the shores and becoming a potential threat to swimmers. But why is this happening? This is due to a change in shark feeding habits, but because they are eating more human of course not! Rather because us humans are over fishing and eliminating the fish/food sources of which sharks normally feed on. This is forcing sharks to come in closer to find food. Us as humans have forced sharks to come in closer and are now killing sharks because of our a...
Shark slaughter has led to shark populations being rapidly decimated all around the globe. Fishermen report that sharks are also getting smaller because they are not being given enough time to fully mature. Although there are other fish that are targeted more than sharks, they are not exactly affected by the kind of endangerment that sharks are currently experiencin...
They have paired fins that lift the shark, as it is able to swim; paired pelvic fins, which stabilize the shark and letting it steer to reach its prey in a more effective manner; dorsal fins also further aide the shark in stabilization as well as the anal fin. For propelling, the shark uses the caudal fins. The caudal fins allow the shark to charge directly toward its prey.
Back in the dynasty the Emperors would serve the dish to honor the guest, because they believed it had healing benefits from the concurring of a shark (Fairclough, Caty). Fin soup still occurs today even when not on special (Fairclough, Caty). In addition the shark fins for can sell for a pretty penny anywhere from $500 a pound or even $1,000 a kilogram (Fairclough, Caty). As a matter of fact, fishermen in Melbour, Segal would export $1300 pounds worth of shark fins a week. It was recorded that a single adult fin sells for $80 and a two-meter monster can sell for $300. Additionally, 1 out of every 100 sharks reported killed between 2000-2008 comes from these fisherman(Hinshaw, Drew). (commentary) about Its question that fisherman practice “unsustainable finning” because it does pay nice , but the amount of money gained by finning isn’t comparable to how much sharks are worth to our economy. The global value of shark finning is around $630 million but is declining, while shark tourism is worth $312 million and promises to be worth $780 million in 20 years ( source 8). Human activity of finning isn’t the only reason to the decline of Great White sharks, human protection is another
Information (sub-point): The solution to the problem of shark finning is to sign petitions and force the government to pass legislature that will ban shark finning, as well as ban the import of shark fins. In 2000, Bill Clinton signed the Shark Finning Prohibition Act of 2000 (SFPA), which “banned finning on any fishing vessel within United States territorial waters, and on all U.S.-flagged fishing vessels in international waters” (Speigel, 2011). Currently, it is also illegal to hunt sharks in many parts around the world due to various restrictions set by other government, but it is not illegal to import and sell shark fins. Finding shark fins in the US can be as easy as walking into an Asian restaurant and ordering shark fin soup. If we truly want to make a difference, and see a rise in the shark populations around the world, we need to ban the sell and trade of shark fins
Thesis: Sharks should be conserved because they are an important part of the ocean, attacks are often incidental, and human behavior influences the behavior of sharks.
Sharks appear to be very vicious creatures that will eat or kill anything in its path. People think that all sharks are harmful and deadly to humans. However, research shows that this statement is not true. Sharks can be trained and tamed. They are just like big, aquatic dogs. Only about 2 dozen types of sharks are potentially harmful to humans. Shark attacks are also much more uncommon than one may think. Despite their fearsome appearances, sharks are not as vicious as they look.
It is no secret that sharks have a bad reputation for being blood-thirsty man-killers. Sharks are known as the “killers of the sea.” Every year, on average, 10 people are killed by sharks; however, every second 3 sharks are slaughtered by humans. So who is the real “killer of the sea?” Sharks are victims to a cruel and inhumane practice known as finning. Finning is a practice that is more practiced in the pacific today but used to be practiced all around the world. Finning refers to when commercial fishermen will pull a shark onto the boat and slice off the fins. The typical target fins that are cut off the shark are the primary dorsal fin, secondary dorsal fin, the lower caudal fin, anal fin, pelvic fin, and the pectoral fins. The removal of these fins leaves the shark a slender, finless carcass. After cutting the fins off, the fisherman toss the still living shark back into the water to die a gruesome and painful death. The practice of finning sharks should be banned and enforced internationally.
Great white sharks are the main predators in the ocean. The only things that are responsible for the deaths of sharks are Age, Health, Humans and other sharks. Humans are responsible for 70% of deaths for great white sharks. Today there are more than 440 known species of sharks. Great whites only have 2-12 babies at one time unlike others who have hundreds. Great whites can live up to 60 years old! Great white sharks are phenomenal animals and but still are vulnerable to extinction. Do your part to kill of the rest of them before they kill you!
Rowat, D., and K. S. Brooks. 2012. A review of the biology, fisheries and conservation of the whale shark Rhincodon typus. Jour. Of. Fish. Bio. 80:1019-1056. (DOI:10.1111/j.1095-8649.2012.03252.x).