Not Afraid of Sharks? Well, Now They're on Cocaine. - The New York Times
S E E D E D C O N T E N T
Researchers have confirmed the presence of cocaine in sharks off the coast of Rio de Janeiro, though questions remain about the effects of the drug.
One of the 13 sharpnose sharks caught by researchers off the coast of Rio de Janeiro. All 13 were found to have cocaine in their system.Credit...Dr. Rachel Ann Hauser Davis
By Sarah Hurtes
July 24, 2024, 8:06 a.m. ET
If the prospect of sharks lurking just off the beach wasn't frightening enough, researchers in Brazil have discovered a new reason to be unnerved: Some of them have cocaine in their system.
In a study published last week, researchers tested 13 sharks off the coast of Rio de Janeiro and found that all had traces of cocaine in their liver and muscle tissues. The levels of cocaine found in these sharks were reported to be as much as 100 times higher than in previously observed marine life.
"We were actually dumbfounded," said Rachel Ann Hauser Davis, a co-author of the study and a biologist at the Oswaldo Cruz Foundation in Brazil. "We were excited in a bad way, but it's a novel report. It's the first time this data has ever been found for any top predator."
This was the first study to analyze cocaine in sharks, following various studies on smaller species, including mollusks, crustaceans and even eels. All 13 sharks examined were found to have unfiltered cocaine in much higher concentrations than in previous studies on other animals, indicating chronic exposure to the drug.
But the study examined only a small sample, leaving many questions about whether the exposure harms the sharks or the humans who eat them.
"I thought it was pretty remarkable that they got it published even with just 13 animals," said Daniel Snow, the director of the Water Sciences Laboratory at the University of Nebraska, who did not participate in the research.
Over a decade ago, Dr. Snow was among the first researchers to measure an illicit drug, methamphetamine, in wastewater in Nebraska. “It’s not too big of a stretch to imagine that these chemicals that wind up in the water can affect aquatic organisms that live in that same water,” he said.
The study in Brazil was conceived earlier this year after researchers discovered high levels of cocaine in the rivers that form Rio de Janeiro’s watershed. Other marine experts had looked into whether sharks in the Gulf of Mexico were ingesting cocaine from the numerous packages lost or dumped in the waters in a 2023 documentary titled “Cocaine Sharks,” which served as an inspiration for the title of last week’s study.
The team of biologists from the Oswaldo Cruz Foundation — an organization affiliated with Brazil’s Ministry of Health — were particularly interested in testing top predators inhabiting these watersheds. Having previously conducted tests on sharks for other contaminants, they sent to a lab samples of the Brazilian sharpnose — a relatively small species of shark from Rio de Janeiro’s coastal waters often consumed by locals.
Dr. Hauser Davis said there were several hypotheses as to how cocaine found its way to the marine creatures, including illegal labs refining cocaine or cocaine packages lost or dumped by traffickers. But she believes these account for only a small amount of the drug found in the ocean.
“We feel that the major source would be excretion through urine and feces from people using cocaine,” she said. Most wastewater treatment plants worldwide cannot effectively filter these substances, leading to their release into the ocean.
Image 
Copacabana Beach in Rio de Janeiro, in 2020. One of the authors of the study said there were several different ways cocaine could have entered the waters there.Credit...Dado Galdieri for The New York Times
João Matias, a scientific analyst at the European Union Drugs Agency, was part of a team that analyzed cocaine levels in wastewater from more than 100 cities, including in Brazil. Their findings revealed that the levels of cocaine in Brazil’s wastewater were similar to those in the European cities with the highest levels.
But he emphasized that the concentrations of cocaine were not very high. Referring to last week’s study, he said, “It’s very important to stress that I’m 100 percent sure that the concentrations they found are super low.”
Tracy Fanara, an environmental engineer in Florida who led the research team for the “Cocaine Sharks” documentary, noted that cocaine was still a small part of the larger problem of pollutants in natural habitats.
“Cocaine gets people interested,” she said. “But we have antibiotics, antidepressants, pharmaceuticals, sunscreen, insecticides, fertilizers. All of these chemicals are entering our ecosystem.”
Dr. Hauser Davis expressed similar concerns. “Why isn’t anyone surprised when you find metals, pesticides and PFAS?” she said.
But she hopes their research will open new doors to testing other animals for cocaine.
“We’re hoping to do other sharks, rays and even sea turtles.”
Sarah Hurtes is a Times reporter working on international investigations from Brussels.More about Sarah Hurtes
Tags
Who is online
30 visitors
Great. And i thought all we had to worry about was cocaine Bears.
Me too!
So Perrie, you need to come to our Great Lakes. Salt and Shark free.
Come to the desert Southwest of Southern Arizona. No sharks here either!😁
Probably had planes go down in the water off the coast crammed with packages of cocaine. Sharks went after the crews for dinner and bit into the packages for desert.
Land sharks?
No, but we have coyotes of the four legged and two legged variety!
Ah yes, the trickster ….. in both varieties.
I don't think blowfish are going to take this news very well...
Well, I understand blowfish. It's their revenge for eating them.
don't make me explain my joke ...
lol … not bad, not bad
I’ll take electrocution.
Or a shot in the head. I don't want to be fish food.
There was a web site that had a list of ten steps for avoiding shark attacks.
I was really surprised that "stay out of the water" was not number one.
Now that is funny!
Next week's move is Cocaine Sharknato!
why not , didnt they have a movie about a bear on cocaine ?
Yep and it was hilarious
LOL ok watch that and ask the question going around , would you want to be alone in the woods with a bear or a man ?
I'll bet none of those asked have ever been alone in the woods with a bear. They lack a frame of reference in which to make the comparison.
Not as fun as Violent Night, but it was fun.
I have to watch this.
But I'm going to take issue with something. It's a black bear. If it were a grizzly I could see it attacking people because that's what they do. But a black bear?
Does being stalked by one count? Not a good feeling I tell ya. Black bear can be sneaky bastards.
Was that that the Santa Claus one?
Yes. I added that one to my 4K BluRay collection.
Excellent movie and I'm not much for movies like this
Apparently the movie took a lot of poetic license. The bear never attacked anyone and died of an overdose. That was probably a horrible death for that innocent bear. All he wanted to do was steal pic-a-nik baskets and have lunch with Boo-Boo
The director was the same one that did Pitch Perfect...
live not far from yellowstone on the Rez , Grizz attacks are reported more its what makes the news , but actually the black bear is usually recorded for more encounters and attacks outside the park area .
two things they have in common though dont mess with mothers with cubs , and people doing stupid things .
people dont realize or can conceptualize just how fast these animals are or can move through thick ground cover . they are tanks .
not as bad as cougars , both kinds .
Yep, another good one
Agreed, we’ve got them in Michigan now.
A fact the DNR adamantly denied …. Until they started showing up on trail cams 10-15 years ago.
I saw a female black bear leap a 6 strand barbed wire fence at the top of a steep ditch like it wasn't even there. A black bear flat out can reach 35 miles and hour.
We had sightings here before trail cams on the sunrise side and one cleared an entire woods of hunters when one started caterwauling.
The DNR also say there are no wolves in the lower either, but we have seen some damn big coyotes.
We had that same issue with the DNR here too. When I was in HS back in the 80's my dad saw one laying in a tree in the front yard of a guy he worked with as he drove by. It was a fairly populated area around a small area lake and very close to the public landing.
Yeah, Wolves are here. Haven’t seen one yet but sign is becoming plentiful.
You got that right, many women might change their pick if that had up close and personal experience with bears in the woods.
I liked the first Pitch Perfect
I was told at a young age to not mess with black bears especially with small cubs
remember as the crow flies , im about 70 miles from the yellowstone border , so i get to hear many many stories of tourists misadventures , as well as mistakenly identifying of animals. most of them would be funny , if they were not so sad because of what most tourists say after the fact . I partially blame it on disney over the years causing people to think animals are sweet docile little fluff balls . For those that dont get into the woods , or experience wild life that often , let me warn , they are NOT docile or cute little fluff balls in real life , they have a better survival instinct than men . thats why women will inherit the earth
A deer gored an uncle of mine and he was in his own front yard. He got medical help and was ok but he didn't antagonize that beastie
Man...I don't even want to think about sharks high on coke. I'm going to Florida next month!
Joking aside I do wonder what the effect of cocaine on a shark would be, I mean our evolutionary paths diverged so long ago that the effect could be anywhere from nothing at all to thinking it was a dolphin to death
Imagine if a Bull shark ingested cocaine. They are mean and vicious to begin with having excess if testosterone that makes them so aggressive to begin with. I can't even imagine one high on coke.
im about to create a jaws moment , Bull sharks are one of the few sharks , that can and do survive and travel in fresh/brackish water ......not even safe from shark attacks , inland in fresh water .
now if i ever meet one that traveled up the Miss, Missouri and others here in Wyoming , ill let y'all know .
all it takes is a river big enough connected to the sea.
Lol the furthest upriver in the Miss a bull shark has been captured is 1700 miles though one was caught 2400 miles up the Amazon. Not sure if that would put it in your neck of the woods, but maybe
shark attack in freshwater river - Search (bing.com)
take your pick .
had to look it up, there is a creek on two ocean pass , that feeds the yellowstone , missouri , and mississippi , to the gulf , but its 3488 miles , and thats not guarenteeing , that the water would be deep enough for a shark to navigate .
it called parting of the waters , on the continental divide , 2 ocean creek splits , one tributary flows west to the pacific one east and ends up in the gulf of mexico.
local joke is people stand where the creek splits and pees in both tributaries at once thus pissing in both the gulf and the pacific at the same time .
Bull sharks ….. fresh water? No problem
drill sgt , too easy , drill sgt ......renaissance man
A more civilized shark would stick with tequila shots ...