WILDLIFE
MARATHON WEEKLY / MAY 16, 2019
“White sharks are protected,” said Rice. “There was a law that was enacted in 1993 that protected them, so populations are rebounding. There is an increase in sharks and increase of people going in the water; there will be an increase in encounters.” Rice references a study that attributes the perceived population increases to the 1993 implementation of the U.S. National Marine Fisheries Service (NMFS) Fishery Management Plan (FMP) for sharks of the Atlantic Ocean. Indeed, Florida Fish and Wildlife Conservation Commission spokesperson Amanda Nalley confirms that great whites are prohibited from harvest. “That means that anglers who hook one are required to release it as quickly as possible. Beginning July 1, shark anglers will be required to meet even more stringent details such as requiring the shark to stay in the water, and requiring anglers to have some type of device to cut the steel leader quickly.” Why is it crucial to protect these shark species, especially in places populated with boaters and swimmers?
SHARK DEATH IN THE KEYS
According to the Florida Museum of Natural History, sharks only kill about six humans a year, while humans kill about 100 million sharks. This week, a reef shark familiar to local divers perished in a net, a cautionary tale of the human toll on sharks. Southpoint Dive Instructor Mike Jackson tells the story:
“These large shark species are apex predators,” said Nowicki, “and they deserve the respect that any apex predator deserves, whether on land or water.” They are also irreplaceable — the loss of apex predators, because of their position at the top of the food chain, can have disproportionate affects on a marine ecosystem. “They can impact entire populations of prey just by being present: what they do, where they go, what they eat, how they eat. These cascades are really important for ecosystems.” People who love the water can peacefully coexist with the creatures that call it home—even those with lots of sharp teeth. Shark bites are very uncommon in the Keys, and almost never fatal. “Most shark attacks occur because someone is standing in murky water, and they take an investigatory bite,” said Rice. Most “attacks” (a misnomer — they are nearly always investigatory bites) with great whites are because of surfing, wherein the person floating on a surf board looks a lot like a seal. We don’t have a lot of surfing in the Keys, and we often enjoy clear water, so we aren’t a prime location for these encounters. To combat what Nowicki calls the “Jaws effect” – responses of horror and fear in the face of white sharks – he recommends moving away from sensationalist media that focus on attack tropes. “Folks need to spend some time with these animals, in an aquarium or out in the wild. I encourage people to get dive certified.” Nowicki says he prepares amateur divers before diving wrecks that may attract sharks by telling them that if they are afraid, they can come back to the surface, no questions asked. But that’s never what happens. “Once you spend some time around the animals, you see they aren’t hunting or killing machines, as they are portrayed. They are big predators that deserve respect, but aren’t out to get people.” So as it turns out, maybe it is safe to get back in the water.
“We go to one spot on Rock Key where sharks hang out. There’s a shark named Roxy that’s hung out for years— they say since 1987. She has a particular snaggletooth, and that’s what we distinguish her by. We went out, and I had terrible visibility. I saw a dead shark lying upside down and its head was through a net. It was a little spooky. It was the same
Patrick Rice with a bluefin tuna, primary prey for great white sharks, whose migratory patterns were the focus of his doctoral thesis. PATRICK RICE/Contributed
GREAT WHITE SHARK FACTS • White sharks have ampullae of Lorenzini, special sensing organs that function as electroreceptors, which detect electrical signals generated by fish or other organisms’ muscles contracting. There is no comparable sense in humans. • The white shark is an “apex predator,” which means that it is at the top of the food chain. The only known natural predator of white sharks is the killer whale. • White sharks were first described by Carl Linnaeus, the “father of modern taxonomy” in his “Systema Naturae” in 1758, though fossils date the species back 16 million years. • In January, divers off Oahu, Hawaii, took photographs of what is believed to be the largest shark ever recorded, named “Deep Blue” and estimated to be 50 years old and weigh 2.5 tons. • There is a “white shark café,” between California and Hawaii in the Pacific Ocean, where tagging projects have shown a high volume of whites hanging out. It hasn’t been established if this is where whites are having their pups, though scientists have posited theories about Pacific and Gulf grounds for having pups. • Rice and partners Eric Stroud and James Hanson developed Shark Defense, a chemical repellent based on necromone, the chemical released from putrified sharks, which can help repel sharks and reduce bycatch for fisheries.
size, and it looked the same as our Roxy, but I wasn’t 100%. We had non-certified divers so I had to be super careful and turned around. When we returned, there was nothing, no trace of her. I assume the net was a fishing net. This is in a marine sanctuary, so there’s no reason it would be out there. Her whole head was stuck through it, and she must have drowned.”
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