logo
How did this shark swim a record-breaking 4,000 miles—a journey once thought impossible

How did this shark swim a record-breaking 4,000 miles—a journey once thought impossible

Yahoo27-05-2025
When Turawa Hakeem caught a bull shark near Lagos, Nigeria last summer, the Ghanaian captain had no idea his crew was reeling a record winner onto his wooden fishing boat.
The eight-foot-long female had made an epic journey of at least 4,500 miles, the longest known movement of its species and the first time a bull shark was documented swimming through two oceans. The shark traveled from the Mozambique Channel in the Indian Ocean, swam around the southern tip of Africa, and then voyaged north through the Atlantic to Nigeria, according to research published this month in Ecology.
'Wow, I was surprised,' says Hakeem. 'I didn't know they could travel that far.'
When his crew began butchering the shark to sell its meat at a local market, Hakeem found a black finger-length cylinder inside its body that read: 'Research: Reward if returned.' Curious, Hakeem emailed the address. He reached Ryan Daly, the paper's lead author and a shark ecologist at the Oceanographic Research Institute, a marine science and service facility that leads research projects in the western Indian Ocean. He implanted the acoustic transmitter in the bull shark in South Africa in 2021.
Daly was equally shocked—and very skeptical at first. 'I thought it might be a scam,' Daly admits. 'The chances of this happening are like one in a million.'
This lucky catch is providing new insights into how bull sharks move and shows how climate change may break down the environmental barriers that historically limited the migration of certain ocean animals.
Another study author and marine biologist at the Nigerian Institute for Oceanography and Marine Research, Dunsin Abimbola Bolaji, confirmed Hakeem's story.
In the year after she was tagged, the female bull shark was detected 567 times along the east coasts of South Africa and Mozambique by an array of 43 different underwater receivers.
Then she disappeared on March 25, 2022 and wasn't seen again until Hakeem's crew caught the shark on July 11 last year.
As part of their shark migration research, Daly and his colleagues also tagged and tracked 102 bull, blacktip, tiger and reef sharks in southern Africa. The longest recorded migration among these sharks was 1,400 miles, just one-third the distance traveled by the female bull shark that ended up near Lagos.
Bull sharks are coastal species, not known for long-distance travel in the open ocean. They prefer shallow waters where freshwater meets the sea and need water temperature warmer than 65°F.
During her voyage north, the female bull shark had to navigate the Benguela upwelling, one of the world's largest cold-water currents that extends along the west coasts of South Africa and Namibia. This upwelling has formed a cold barrier separating Africa's bull shark populations for at least the past 55,000 years.
Scientists think this bull shark bypassed the cold water by swimming out around the upwelling, which can extend up to 90 miles offshore. It's also possible she rode pockets of warmer water around South Africa into the Atlantic Ocean during a Benguela Niño event.
This climate pattern is similar to the El Niño events that influence sea temperatures off the west coast of the Americas. Certain cold-water fish, like mackerel and sardines, have also been pushed north during Benguela Niño events.
As waters warm and upwellings shift due to climate change, Daly says the Benguela's cold water barrier may break down more often, allowing ocean animals to move to different latitudes. These Niño-related water temperature changes can change the entire species makeup of certain marine areas, impacting everything in the food web from algae to plankton to sharks.
For bull sharks, however, more movement is likely a positive sign. 'If it means more gene flow, then typically that's a good thing,' Daly points out. 'We need to adapt to survive in a changing world.'
Daly thinks that perhaps she was an immature shark who was 'just exploring'. Females don't reach sexual maturity until they are around 20 years old. Then they repeatedly return to the same estuary to reproduce. Until then, however, they may head out to 'find their groove and the pattern that works for them,' Daly says.
It's possible that this female's extraordinary journey 'might not be unusual at all', says Rachel Graham, a shark biologist who was not involved in this study and executive director of MarAlliance, a conservation nonprofit based off the west coast of Africa.
Bull sharks may have always traveled farther than scientists realized, or perhaps this female was the 'the black sheep in the family, the one who does something completely and utterly different to keep our gene pool robust,' Graham suggests.
Despite her long journey, this female won't pass on her genetics after befalling a common shark fate. Globally, sharks' numbers have been halved since 1970. Overfishing drives 90 percent of the decline in sharks—but three-quarters of the estimated 100 million sharks that are caught each year are killed accidentally.
As stocks of other fish plummet globally, more people are turning to shark meat for protein—especially in countries in sub-Saharan Africa like Nigeria where people depend on fishing for their livelihoods.
'It had a one-way ticket there because fishery pressure is so extreme,' Daly says. 'Sharks are running the gauntlet. In every country, they're facing different types of threats on top of climate change.'
Hakeem says his crew didn't hook the tagged female bull shark on purpose. She took the bait meant for more lucrative grouper and snapper.
To ensure sharks—including future record breakers—survive, Graham says that scientists need to rely more on fishers like Hakeem to track sharks and to learn whether other marine species are making transoceanic journeys.
'Small-scale fishers are our allies in science,' Graham says. 'They have PhDs of the sea.'
These sorts of novel partnerships may help scientists better understand how and where marine species are moving into new habitats.
Warming water may allow tropical species to expand their range polewards, which can relieve fishing pressure or allow them to spread to new homes. But simultaneously, climate change is also creating more intense cold events in their historic ranges, such as an extreme upwelling along the southeast coast of South Africa that killed individuals from 81 species in 2021, including sharks.
'It's kind of like this bait and switch,' Daly says. 'It gets warmer but then these intense upwelling events increase, so they might get trapped down there, at the end of their range for a tropical species and then die off.'
Orange background

Try Our AI Features

Explore what Daily8 AI can do for you:

Comments

No comments yet...

Related Articles

Meet the robo-bunny: This tiny, furry robot is taking on invasive pythons in Florida
Meet the robo-bunny: This tiny, furry robot is taking on invasive pythons in Florida

Yahoo

time6 days ago

  • Yahoo

Meet the robo-bunny: This tiny, furry robot is taking on invasive pythons in Florida

Among the cypress and sawgrass of South Florida, a new weapon in the state's fight to remove invasive pythons lurks, waiting to entice its prey. Yes, it's a mechanical rabbit. Just don't call it the Energizer bunny. Researchers at the University of Florida have outfitted 40 furry, fake toy rabbits with motors and tiny heaters that work together to mimic the movements and body temperature of a marsh rabbit — a favorite python meal. The fluffy army's mission? Help conservationists remove the highly destructive serpents that have invaded the state's ecosystem Florida's 10-day python challenge: Why hunters are chasing invasive snakes in the state Why are they using robot rabbits? The bunnies spin. They shake. They move randomly, and their creation is based on more than a decade of scientific review that began with a 2012 study that transported rabbits into Everglades National Park to see if, and how quickly, they would become python prey. 'The rabbits didn't fare well,' said Robert McCleery, a UF professor of wildlife ecology and conservation who's leading the robot bunny study that launched this summer. Subsequent studies revealed that pythons are drawn to live rabbits in pens with an average python attraction rate of about one snake per week. But having multiple live rabbits in pens spread across a formidable landscape is cumbersome and requires too much manpower to care for them. So, why not robot bunnies? 'We want to capture all of the processes that an actual rabbit would give off,' McCleery said. 'But I'm an ecologist. I'm not someone who sits around making robots.' Instead, colleague Chris Dutton, also a UF ecology professor but more mechanically adept, pulled the stuffing out of a toy rabbit and replaced it with 30 electronic components that are solar-powered and controlled remotely so that researchers can turn them on and off at specific times. The rabbits were placed in different areas of South Florida in July 2025 for a test phase that includes a camera programmed to recognize python movement and alert researchers when one nears the rabbit pen. One of the biggest challenges was waterproofing the bunnies so the correct temperature could still be radiated. McCleery was reluctant to give specifics on where the rabbit pens are located. 'I don't want people hunting down my robo-bunnies,' he said. Version 2.0 of the study will add bunny scent to the stuffed rabbits if motion and heat aren't enough to fool the snakes. Why are Burmese pythons a problem? Burmese pythons aren't native to Florida. They were introduced to the state through the pet trade in the 1970s and release over time into the wild. The snakes gained a foothold in Everglades National Park by the mid-1980s, according to the 2021 Florida Python Control plan, and quickly proliferated, threatening other key species in the ecosystem. A 2012 study by the United States Geological Survey found the pythons had contributed to population declines of a half-dozen animals, including racoons, opossums, bobcats, foxes, marsh rabbits and cottontail rabbits The United States Geological Survey puts the Burmese python population in the Everglades in the tens of thousands. Pythons have migrated north from the park, and researches believe they may be able to survive as far north as Georgia if temperatures continue to warm and the snakes burrow during cold snaps. What else is Florida doing to control the python population? State officials trying to mitigate the python population have turned to many strategies – with varying degrees of success. Renowned snake hunters from the Irula tribe in India were brought in to hunt and share their skills. People have used near-infrared cameras for python detection and specially designed traps. Some pythons are tracked by the DNA they shed in water. The annual Florida Python Challenge has also gained legendary status, attracting hundreds of hunters each year vying for the $10,000 grand prize. The 10-day challenge was developed by the Florida Fish and Wildlife Conservation Commission to remove the pythons from state land. This year's challenge runs through July 20. Starting in 2017, the South Florida Water Management District and the Florida Fish and Wildlife Conservation Commission also began paying 100 bounty hunters hourly wages and bonuses based on the length of the snake caught. The hunters have removed an estimated 15,800 snakes since 2019 and were called the 'most effective management strategy in the history of the issue' by district invasive animal biologist Mike Kirkland. Kirkland oversees the district's hunters. Kirkland oversees the district's hunters and is involved in other python removal projects, including the robo-bunny experiment. 'It's projects like (McCleery's) that can be used in areas of important ecological significance where we can entice the pythons to come out of their hiding places and come to us,' Kirkland said at the board meeting. 'It could be a bit of a game changer.' Euthanasia or execution? Lawsuit says government wrongly killed Peanut the squirrel McCleery said he's pleased state officials are willing to experiment. 'Our partners have allowed us to trial these things that may sound a little crazy,' McCleery said. 'Working in the Everglades for 10 years, you get tired of documenting the problem. You want to address it.' McCleery said researchers did not name the robot rabbits, although he did bring one home that needed repair. His son named it 'Bunbun.' Contributing: Kim Luciani and Karissa Waddick, USA TODAY Network This article originally appeared on Palm Beach Post: Army of robot rabbits deployed in fight against Florida pythons Solve the daily Crossword

Hey old bird: A 33-year-old puffin on New Brunswick island going strong, with a chick
Hey old bird: A 33-year-old puffin on New Brunswick island going strong, with a chick

Yahoo

time12-07-2025

  • Yahoo

Hey old bird: A 33-year-old puffin on New Brunswick island going strong, with a chick

FREDERICTON — Daniel Oliker held a 33-year-old puffin from Machias Seal Island in his hands and was in awe about how it was a decade older than him. It felt like he was holding a world of knowledge and history in that puff ball of black and white feathers. The University of New Brunswick graduate student, researching Atlantic puffin ecology, found a bird with a plastic band dating back to 1992. It showed the tuxedo bird to be a wise and worldly 33. And it had a chick. Machias Seal Island is a flat, treeless sanctuary for seabirds located about 19 kilometres southwest of New Brunswick's Grand Manan Island at the mouth of the Bay of Fundy. It has about 8,600 breeding pairs of puffins. Oliker said last week his fellow researcher spotted one of the tuxedo birds on the island with a faded, green-and-white plastic band, and marked the area where it was seen. Those bands were used by Canada Wildlife Services starting in the 1970s until around 1995, when they started being replaced with metal ones. Around midnight Oliker and a couple of researchers went to search the burrows — nests where puffins rest at night after a day at sea — looking for the old bird. After searching a few burrows, he said he found the right bird by feeling the bands on their legs. A few had metal bands. "Then I felt one that felt a little bit different, and it was in the right location that we marked so I pulled it out and it was the right guy," he said in an interview from the island. The old bird was curious and didn't put up much of a fight when it was pulled out. The researchers replaced the plastic band with a metal one, giving the puffin its new number: JG18. But they don't yet know its gender. That he was holding one of the oldest birds, Oliker said, was "very exciting" and "truly amazing." Most puffins in the wild live up to their mid-20s. "Just to think of how many years he spent out on the open ocean. How deep he's dived before. It's fascinating to think about just how much this bird has gone through, what it's seen, and the fact that it's still here and raising a chick. It speaks to its persistence." The chick was a "decent size," which was pleasantly surprising because puffins are struggling this year from a seeming lack of food, he said. There have been a number of eggs that haven't hatched and several pufflings — babies — have died, he added. "It is very probable that this puffin, being so old, has experience and knows what it's doing. So it's been able to find a good burrow for its mate, himself and the egg, and then able to produce a chick," he said. "It's very likely, because he's been alive for so long, that he knows which spots might be better for fish." Puffins start reproducing around four or five so JG18 has probably had more than 25 chicks in its lifetime even if all didn't survive, Oliker said. Nick Lund, a network manager for U.S. wildlife conservation organization Maine Audubon, said one of the biggest threats facing Atlantic puffins in the Gulf of Maine is climate change. "The Gulf of Maine is the southernmost breeding area for puffins in the Atlantic, but the water is warming very quickly," he noted. "New fish species are moving in to the warming waters, and other fish species — those traditionally eaten by puffins — are moving out. Whether or not puffins can adapt to eat the new fish species is a major question mark for their continued survival in the gulf." The International Union for Conservation of Nature lists puffins as "vulnerable," which means they face a high risk of extinction in the wild. Finding these "very" old puffins is interesting and important because it provides data confirming longevity, said Heather Major, a marine biology professor at the University of New Brunswick, who is studying these birds on Machias Seal Island. A paper published last year in the journal Ecology and Evolution said adult survival of puffins has declined over time, which is particularly concerning because they are an important component of population growth rate. Puffins are a cold-adapted, northern species in this region that have been exposed to some of the warmest waters in comparison to puffins in other regions, she said. "(The finding of JG18) is important information given recent warming in the region," she said. Oliker said he hopes he can see the puffin for the next few years. "We have yet to give him a name," he said. "Now that he has a new band and we know which guy he is in the database, we can come up with a name, and maybe it'll be fun to see if he's still around the next few years. And we can call him by his name." This report by The Canadian Press was first published July 12, 2025. Hina Alam, The Canadian Press

How the Trump administration is already cutting off climate research
How the Trump administration is already cutting off climate research

Washington Post

time05-07-2025

  • Washington Post

How the Trump administration is already cutting off climate research

A $15 million federal grant was supposed to help scientists better understand how the warming climate is harming plants and animals, setting many on paths toward extinction. But the Trump administration shelved it earlier this year, miring the research in a holding pattern. Jacquelyn Gill isn't sure there's a way out. The professor of paleoecology and plant ecology at the University of Maine spent hundreds of hours readying the grant proposal, and 13 years before that gathering knowledge about how past changes to Earth's climate echoed through ecosystems. But without federal funding, she finds herself at a loss for how to keep building on that work as more species disappear.

DOWNLOAD THE APP

Get Started Now: Download the App

Ready to dive into a world of global content with local flavor? Download Daily8 app today from your preferred app store and start exploring.
app-storeplay-store