What Types of Sharks Are Found in U.S. Waters and Are They Dangerous?

Many types of sharks are found in Atlantic coastal waters and along the Pacific Coast. Among those reported in the U.S. include the great white shark (or simply known as the white shark)—which are among the top predators—and the whale shark, the world's largest fish.

According to the U.S. National Oceanic and Atmospheric Administration (NOAA), there are over 50 species of sharks in the waters off the country's East Coast alone.

The Shark Research Committee, a nonprofit research group, says there have been at least 34 shark species recorded off the Pacific Coast, mostly around California, Alaska and Oregon in the U.S.

Are All Sharks Dangerous?

The International Shark Attack File (ISAF) that is administered by the Florida Museum of Natural History—explains: "Say the word 'shark' and the first image most people conjure up is a Jaws-inspired white shark devouring unsuspecting bathers while well-meaning authorities and scientists helplessly stand by."

But contrary to what most people might think, most sharks do not pose a threat to humans.

Speaking to Newsweek, Dr. Mike Heithaus, a marine ecologist who specializes in predator-prey interactions and the ecological importance of sharks and other large marine species, said: "Most sharks are no threat at all to people unless they are harassed or grabbed. The vast majority of encounters - even with larger species - do not pose a risk to people."

Sharks on U.S. Atlantic Coast

Sharks in the East Coast range from the small spiny dogfish to the much larger white shark and the sharks here are "found in just about every kind of ocean habitat," the NOAA says.

The Atlantic blacktip, spinner, Atlantic sharpnose and lemon sharks are among the species more prominent in nearshore waters of the coast's southeast region.

Sandbar, sand tiger and smooth dogfish sharks frequent the waters near the shore of the Mid-Atlantic region, especially during the summer. These are also found in New England waters, where spiny dogfish and white sharks also commonly swim in search of their natural prey, according to the NOAA.

Most Atlantic sharks are reported to spend at least a portion of their lives in coastal waters. Many species go in search of food through the bays and estuaries along the U.S. coast.

Other species are known to be "open-ocean dwellers that use shallower waters as nurseries or occasional feeding grounds," the NOAA explains.

Sharks on U.S. Pacific Coast

Over on the Pacific Coast, sharks have been reported in coastal waters stretching along California, Alaska and Oregon.

Some of the sharks reported in the region include the broadnose sevengill shark (most abundant off the coast of Central California), the smooth hammerhead (found along Central California to the Gulf of California), megamouth shark (found in Southern California) and the leopard shark (in the waters from Oregon to Baja California and the northern part of the Gulf of California).

According to the Shark Research Committee, whale sharks, which can grow up to 40 feet and weigh as much as 40 tons according to some estimates- can be found "occasionally off Southern California."

White sharks have also been reported to be in the waters from the Gulf of Alaska to Gulf of California in mostly shallow coastal waters, according to the committee.

The NOAA says these apex predators, found mostly in temperate and subtropical waters, spend time both far out at sea as well as near the coasts.

In the northeastern Pacific region, "young of the year and juvenile white sharks" are commonly found along the Southern California Bight and further south into the Vizcaino Bay area of Mexico, according to the government body.

"White sharks expend a significant amount of energy migrating across the Pacific and need to accumulate as much energy as possible during their short feeding season in sanctuary waters," the NOAA explains.

Sharks in U.S. Most Dangerous to Humans

Speaking to Newsweek, Dr. Gavin Naylor, the director of the Florida Program for Shark Research at the Florida Museum of Natural History, said: "The most frequent [shark] bites are from requiem sharks that are targeting schooling fishes," such as blacktip sharks.

Larger species, such as bull sharks, tiger sharks and white sharks, naturally pose the greatest threat for more severe injuries, said Naylor, who is also the curator of the Florida Museum of Natural History.

"A nibble from a white shark can be fatal if it severs the femoral artery of a swimmer or surfer," he explained.

Speaking to Newsweek, Heithaus, who is also the dean of the College of Arts, Sciences & Education at the Florida International University (FIU) and a professor in FIU's department of biological sciences, said bull sharks, tiger sharks and white sharks are the most dangerous shark species people are likely to come across.

"But even for these species, it is only large individuals that are a real threat and even these individuals will ignore people in most circumstances,"

Shark Attacks in the U.S.

According to the ISAF, in the U.S. there have been nearly 1,500 "confirmed unprovoked shark attacks" reported across 21 different states from 1837 to the present.

The vast majority of the attacks have been in Florida, where 868 such attacks were reported since 1837.

The Florida museum's Naylor told Newsweek: "There are about 530 different species of sharks in the world. Only about 30 of these have ever been implicated in biting people, and of these about 10 species are responsible for more than 90 percent of shark bites on people."

The FIU's Heithaus told Newsweek: "In the vast majority of places, sharks are less of a danger to people than the actual drive to the beach. The same is true for rip currents or other risks they might encounter."

In their lifetime, people are more likely to die from heart disease and other health conditions (such as the flu and an excessive cold), car accidents and lightning than from a shark attack, based on data from the U.S .National Safety Council, the U.S. Centers for Disease Control and Prevention as well as the ISAF.

How to Survive a Shark Attack

Naylor told Newsweek the most important aspect to bear in mind for survival after being attacked by a shark is to "get out of the water and stop the bleeding."

Naylor said: "Remove yourself from the environment. Always keep your eye on the shark when leaving the water.

"Once on the shore, stop the bleeding with a make-shift tourniquet or direct pressure. Call for help," he added.

There are also several ways to avoid a shark attack, such as staying clear of "some areas where we know large sharks congregate," the FIU's Heithaus told Newsweek.

"For example, people should probably avoid seal or sea lion colonies because that's where you might find white sharks. Predators often are more active near dusk and dawn.

Heithaus explained that in places where sharks might be more common, "it's best to avoid areas where people are fishing and where there is a lot of potential prey in the water" to help reduce the chances of an encounter with a shark.

Here are some quick tips to avoid shark attacks and stay safe in the water, as outlined by the ISAF:

• Swim with a buddy
• Stay close to shore
• Don't swim at dawn or dusk
• Don't swim around schools of fish or where people are fishing
• Avoid wearing jewelry
• Avoid excess splashing

See the ISAF website for more information.