The seal attack on Saturday marked the fourth time a shark has been spotted at Nauset Beach, leading to the closure.
About a half-a-dozen sharks were captured enjoying a feeding frenzy in North Carolina waters.
New Smyrna Beach on the state's central east coast is considered to be the shark attack capital of the world, according to the International Shark Attack File.
Blacktip sharks can grow up to eight feet long and nearly 300 pounds in weight.
Researchers say they were stunned by the close encounter.
The bluntnose sixgill is one of the largest sharks in the world and it has not changed much in around 180 million years.
"In the history of fisheries science, only two pocket sharks have ever been captured or reported," Henry Bart, director of the Tulane Biodiversity Research Institute, said in a statement.
The oldest embryo kills and consumes its siblings, causing it to grow exponentially bigger and stronger.
Jeff Weakley was bitten by an unidentified shark while surfing in the waters off Flagler Beach in 1994.
"Selfiecides" account for more than five times the number of fatalities, and the numbers are only rising.
Shark attacks 19-year-old surfer off the coast of North Carolina as he swam in the water with his brothers.
One-hundred percent of the profits go to saving the sharks.
The men were fired from their jobs over the violent incident.
A marine biologist says the footage of the sharks hunting is the best his team has ever captured.
"Sharks are being lifted out of the Atlantic Ocean and dumped into the storm because it's so strong."
Bonnethead shark, a relative of the hammerhead, eats seagrass for nutrition—and may be able to survive on it alone.
Little is known about the world's second largest shark.
These sharks are now the most popular in the ocean.