As dead sawfish began washing onshore in the Lower Keys this winter, state researchers and wildlife officers raced to respond to the mounting number of endangered fish thrashing on beaches, circling flats and uncharacteristically jerking their toothy rostrums out of the water.
One was spotted near Marathon in a channel once used for a James Bond movie scene. The same day another appeared miles away, south of the Key West airport, then even farther away, in the remote Mule Keys.
On social media, pictures from the Southernmost Point in Key West competed with videos of smalltooth sawfish pitching onto beaches and swimming into seawalls near the popular tourist town.
Then late last week, videos posted on YouTube looked showed a large sawfish swinging its rostrum out of the water in Boynton Inlet, looking eerily similar to images from the Keys.
Altogether, the trail of sick or dead sawfish in the Keys stretched across 78 miles of shallow water, from Boca Grande to Long Key State Park, according to records from Jan. 30 to March 5 released to WLRN. By mid-February, records show, reports began flooding a state hotline, sometimes up to six a day.
Using the records, WLRN compiled an interactive map howing the approximate locations for dead and sick sawfish reported to the hotline. Because sawfish are endangered, exact locations were redacted and only the name of the closest Key was provided.
“I've lived in the Keys my entire life. I've never seen anything like this,” said Republican state Rep. Jim Mooney, a former teacher, real estate agent and mayor of Islamorada elected to the Legislature four years ago. “There's usually some kind of relatively easy fact behind when they start to get stressed. But this is an anomaly.
Mooney convinced lawmakers this month to set aside $2 million in emergency funding to try to unravel the mystery that’s also stressing, and sometimes killing, dozens of other fish species.
“You got to ask yourself, is this something to do with last summer's heat that has some kind of offshoot that we haven't seen before?” he said. Sawfish “are basically a dinosaur, so they have survived some very harsh conditions over the course of their life on Earth. And for them to be floundering and dying is super concerning.”
The dead sawfish capped a simmering, but mostly out-of-sight event that started in November, months after an extreme ocean heatwave swept across South Florida and spiked inshore water temperatures by 5 degrees on average. Days of sizzling temperatures bleached coral throughout the Keys and baked other important life: jellyfish also bleached, sponges died and spongy mats of halimeda, a plentiful macroalgae, wilted.
Alarmed fishing guides and anglers reported seeing fish behaving strangely. Many circled and seemed to struggle to maintain equilibrium. Whatever was ailing them appeared to be indiscriminate, afflicting species as small as minnows and pinfish, as well as sturdier snook, tarpon and Goliath grouper. The Lower Keys Guides Association reached out to the Bonefish Tarpon Trust, which organized a team of researchers and state wildlife biologists the second week of January to begin studying the escalating event.
Then in late January, the first sawfish turned up dead, deepening the mystery.
“Given how rare sawfish are, and there are a lot of other big animals out there and they're not turning up on the beaches in the shallows,” said Dean Grubbs, a Florida State University coastal fish ecologist who studies sharks and sawfish and is a member of the National Oceanic and Atmospheric Administration’s sawfish recovery team. “It's mostly the sawfish.”
Nearly all the dead sawfish have had necropsies performed by Florida Fish and Wildlife Conservation Commission’s sawfish research program based at its Charlotte Harbor field laboratory. Lead scientist Gregg Poulakis, who has referred questions to FWC media staff, has been investigating the fish for more than a decade.
“They're going to open them up and start looking into their internal organs,” Grubbs said. “You might look at their digestive tract. You might look at the liver, gallbladder and kidneys. Do they look normal? Maybe you'll take bile from the gallbladder. Those are your filtration organs so those are the ones that are going to filter any toxins.”
They’ll also likely take blood samples. Blood he collected from 11 apparently healthy sawfish in February are being used as comparison, Grubbs said. Older samples from about 100 sawfish tagged and examined over the years will also be provided by biologist Jim Gelsleichter at the University of North Florida, Grubbs said. These contain blood and genetic material used to examine reproduction and eating habits.
“We don't have a lot of other samples available, so they're using whatever is available, which is mostly going to be blood plasma,” Grubbs said.
Meanwhile, a separate pathology team is continuing to work to identify the toxin making other species sick.
Fish have tested positive for multiple toxins, including one found in ciguatera - food-borne illness caused by eating fish contaminated with ciguatoxin - that was initially thought to be the cause.
But the appearance of other toxins has complicated that theory and no smoking gun has emerged, Florida Gulf Coast University algae expert Mike Parsons said. His team has not received samples from the dead sawfish, but he said results of necropsies would not necessarily shed light on toxins identified by pathologists.
State researchers began monitoring them in the 1990s, even before sawfish were added to the endangered species list in 2003, so they have the most expertise, Grubbs said. But the number of experts in the field is small. Only five species of sawfish exist, and the only one in the U.S. is only reliably found in South Florida.
“There are only a limited number of people that are even permitted to work with them,” he said. “Within FWC, there's not very many people that work on sawfish and have never looked inside of a sawfish. So it is a pretty small group. So yeah, they're up to their elbows.”
First findings in January
Since January, when the first dead sawfish was found near a marina on Geiger Key, experts have been scrambling, records show. The following two weeks, five dead female sawfish turned up dead between Cudjoe Key and Key West.
Numbers jumped the following week, records show. Four more were found dead and another six thrashing or stranded in shallow waters in a widening circle as far south as the Mule Keys and north to Big Pine and the toney Little Palm Island resort. Seven more were found on Feb. 22.
In late February and early March, numbers and locations mounted: a resident filmed one swimming onto rocks at the White Street pier in Key West. A caller on Boca Chica saw what appeared to be a dead sawfish on rocks but swam away when its rostrum was freed. In Bahia Honda, a caller reported a sawfish stranded on the beach that later approached kayakers in deeper water. Dead sawfish were found at faraway Boca Grande and in Shark Channel.
For each report, FWC officers and staff from the Sawfish Research Program in Charlotte Harbor or the Fish and Wildlife Research Institute in Marathon scrambled to respond, records show. Sometimes they got help from staff at the Seacamp science center in Big Pine or researchers from the Bimini biological field station working in the area.
Dead sawfish were usually taken to the Charlotte Harbor field station to be necropsied. When they could, researchers tagged sawfish that were still alive and pushed them into deeper water. Some bore tags, although none were tagged previously by Grubbs.
Other than being mostly large, adult sawfish, Grubbs said no clear patterns are evident. Both male and female are among the dead. And while most were spotted on the Atlantic side, he said that could be a factor of observational bias: the back country has more mangroves where fish can hide and fewer people are watching.
Recent video from the Boynton Inlet is troubling, he said.
“I don't know if that's the same thing happening or not,” he said. “But if it is, and it's moving north, that's even more of a concern.”
Anyone who sees unusual fish or sawfish behavior should report it to authorities, Grubbs said. Those reports will help scientists understand how far things have spread or if they’re continuing.
Sawfish information should be reported to FWC’s sawfish hotline at 844-472-9374, 1-844-4SAWFISH, or by email to Sawfish@myfwc.com. Other fish should be reported to FWC’s fish kill hotline at 1-800-636-0511 or online at MyFWC.com/ReportFishKill.
This story was produced in partnership with the Florida Climate Reporting Network, a multinewsroom initiative formed to cover the impacts of climate change in the state.
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