MELBOURNE, Fla. – You may have heard of Sharknado. Now consider “Hurrishark.”
But unlike in the popular sci-fi comedy film, where sharks fall from tornadoes in man-eating frenzies, researchers are finding a real-life stormy drama in which sharks’ heightened senses at sea offer huge untapped potential to improve hurricane forecast models — a prospect far from science fiction, according to News 6 partner Florida Today.
[RELATED: Talk to Tom: Researcher says sharks can predict hurricanes]
As Discovery Channel’s Shark Week taps primal fears this week, researchers point to mounting proof of the world’s most-feared predator’s seemingly limitless potential to save far more humans than they kill. One way: they can teach us how to stay out of harm’s way during deadly hurricanes.
“This is an idea that’s been out there for quite a while, using animals as oceanographers,” said Michael Heithaus, a shark researcher and executive dean of the College of Arts, Sciences and Education at Florida International University.
Some sharks act like unflinching storm chasers, while others are storm duckers, diving to safer, deeper waters. Their movements before, during and after storms have tons to tell us about how hurricanes turn and intensify, researchers say. While we see five-day cone warnings, sharks sense dips in air pressure surrounding hurricanes as much as two weeks ahead of time and head for deeper water when the storm is still some 100 miles away.
We fly expensive planes and drones into hurricanes, deploy 16-inch tubes called dropsondes equipped to measure temperature, pressure and humidity or send underwater “glider” drones to try and keep up with or buck the storm’s powerful currents. But sharks and other fish already in or around the storm can be tapped as sentinels of disaster. They can sense the danger and gather the data safer, cheaper and faster — in real-time via satellites, researchers say. And they can outswim the best of underwater weather drones.
These toothy beasts’ super sensory powers could help find one of the holy grails in hurricane prediction: more precise predictions of storm severity.
Advancements in satellite tagging technology have thrust sharks and other animals closer to center stage in hurricane hunting and modeling.
“We have this kind of new capacity to put these smaller and smaller sensors, on a different suite of animals, including sharks, and then the data can get transmitted directly into the sort of oceanographic data pipeline and be available in the same places as the all those traditional datasets from from buoys and gliders,” said Tobey Curtis, a fishery management specialist for NOAA Fisheries in Gloucester, Massachusetts.
“Animals that are instrumented with these kind of fancy new satellite tags,” Curtis said. “They have the capability to capture these oceanographic data that can inform hurricane models, which is really cool. And some of the benefit is that they can be much less expensive than sending out an oceanographic survey vessel.”
It began with seals
Pioneers of the concept tagged elephant seals in the 1980s to gather oceanographic and meteorological data in hard-to-reach polar regions. Other attempts have tagged whales, sea turtles and birds, which also sense dips in barometric pressure and electrical fields from hurricanes.
While most efforts to date have only included a dozen or so tagged sharks, scientists say the concept could be scaled up with a fleet of thousands of roving shark forecasters, with varying surfacing habits, to fill data gaps in places expensive planes and drones can’t cover.
In many instances sharks seem to know better where the hurricane is going well before the meteorologists do. So knowing sharks better means knowing storms better, scientists say.
Sharks have built in oceanographic sensors with the capacity to measure temperature and conductivity “with an accuracy comparable to ship-based conductivity-temperature-depth casts or autonomous drifters,” according to one recent study by University of Delaware, Stanford University, and NOAA Fisheries.
Federal researcher began using underwater “glider” drones to measure ocean heat in 2012. But such expensive projects tend to find the gliders too slow and weak in currents. Sharks, some of the fastest swimmers around, can top 45 mph, putting drones to shame.
“One of the benefits to using sharks is that they swim across currents,” said Curtis, a coauthor of the study. “They move kind of randomly. We can’t make them swim in a grid pattern or something yet to accurately sample things. But they can move to places or sample parts of the ocean that are tough to get to by ship, or buoy or glider or these other typical traditional oceanographic data sources.”
Sharks even seem to sense the difference between an approaching hurricane and a typical Florida storm.
“You can get big pressure drops with thunderstorms, and we don’t see any evidence of them getting out of the system when the big thunderstorms come through,” Heithaus said.
The Delaware, Stanford and NOAA researchers say sharks in the Mid-Atlantic Bight, which stretches from North Carolina to Massachusetts, have “enormous untapped potential” as harbingers of hurricanes to directly benefit coastal communities. Tagging more open-ocean shark species could generate high-quality information about the changes in conductivity, temperature and other data vital for predicting hurricane paths and intensity. This could “greatly improve regional oceanographic and hurricane models by providing real-time oceanographic data to the Integrated Oceanographic Observation System (IOOS),” the researchers wrote.
The IOOS is a national network that, among other ways, gathers ocean data via satellites, buoys, tide gauges, radar stations and underwater vehicles, and now increasingly, animals. “There’s a lot of data coming off the backs of animals that are going to be a part of that,” Heithaus, of FIU, said.
Early tries using animals to help predict hurricanes focused on marine mammals that regularly surface for air, such as whales. But Curtis and other researchers increasingly see significant unrealized potential for sharks, a non-air-breathing species that still surfaces regularly.
Researcher use battery-powered transmitters that send radio signals picked up by the Argos satellite system to analyze tag data.
Sensitive shark snouts sense storms’ electrical fields from afar
A shark’s ability to smell, feel or otherwise home in on targets from afar is unparalleled at sea. Through a series of sensory pores in their snouts, sharks can sense extremely weak electric fields, including those in prey used to move muscles or make hearts beat.
A 2007 Scientific American article likened this to sensing the field created by a 1.5-volt AA battery, with one pole dipped in waters off Jacksonville and the other into the Long Island Sound. A shark swimming between the two could, in theory, easily sense whether the battery was on or off. That super power enables them to sense the electrical fields created by hurricane winds and waves.
Should I stay or should I go now?
Like humans, sharks may weigh multiple risk-benefits of evacuation, research shows.
Millions of years of evolution showed them the way. They’ve been around way longer than us. Their environmental cues include perceived predation risk, size, shifting prey when making evacuation decisions during and after hurricanes.
Smaller sharks escape hurricane turbulence in coastal waters for deeper, calmer waters. If they stay, they can get pushed onto land. But larger sharks tap a different decision matrix.
A 2001 study by Mote Marine Marine Lab in Sarasota found blacktip sharks, a breed on the smaller side, responding to pre-storm drops in air pressure, fled to deeper water before Tropical Storm Gabrielle hit the central Gulf Coast of Florida. The response was consistent for all the fish being studied, and all blacktips returned to shallow nursery areas after the storm, suggesting it was an innate behavior, the authors concluded.
In 2017, University of Miami and Canadian researchers tagged sharks with acoustic telemetry devices during Hurricane Irma. They found the sharks swam to deeper waters before Irma made landfall. As Irma passed Miami, most nurse sharks, bull sharks and great hammerheads evacuated the shallows of Biscayne Bay to deeper waters. Past studied observed small sharks doing the same.
Larger sharks, such as tiger sharks, use the opportunity for a feeding frenzy, scavenging the smaller, weaker and injured: fish, birds and invertebrates. battered by debris.
Some big sharks fear no cyclone. In September 2016, the UM and Canadian researchers found big tiger sharks stayed in shallow inshore waters in the Bahamas despite a direct hit from Hurricane Matthew, a Category 5 storm. Right after Matthew, tiger sharks doubled in those waters, ostensibly to feed off the dead, weak and injured marine life.
Tagging a shark to tell more about hurricanes has its limits. Researcher have yet to scale up shark and other marine animal tagging to collect enough information to predict storm patterns reliably. Thousands of sharks or other fish would have to be tagged.
“You’re still sort of rolling the dice on, ‘are the animals in the area?’ " Heithaus, of FIU, said. “You can’t tell them where to go.”
And if all the sharks and other tagged animals flee to the same spot, it might not necessarily be where hurricane models seek the most telling data. “It’s more that it’s a great accessory tool, potentially,” Heithaus said.
“It would probably take quite a few animals moving around out there,” he added. “It’s good to have all the pieces of the puzzle you can have, even if they’re small pieces.”