After generations of speculation, scientists have finally managed to track European eels the entire way back to their breeding grounds in the Sargasso Sea – following their movements thousands of kilometers along what is considered one of the most impressive animal migrations in nature.
Scientists are excited because scientists have finally found direct evidence of an important part of the eels’ life cycle that was suggested almost 100 years ago.
Up to now, there have been no eggs or eels found in the Sargasso Sea of North Atlantic Ocean. This confirms that this is where eels breed.
Kim Aarestrup, a study author and fish biologist at the Technical University of Denmark, said that “eels have piqued scientists’ curiosity for millennia.” Tweeted by.
“We followed the eels to their spawning ground for the first time.”
Danish biologist, in the 1920s, was a pioneering figure. Johannes SchmidtThe Sargasso sea was home to eel larvae, which are far removed from their coastal habitats in Europe or Africa, as well as their estuarine and freshwater environments.
Schmidt published his results in 1923. This was the beginning of the next century’s research into how eels reproduce. His efforts were described“Disappointment alternating with encouraging discoveries and periods that have seen rapid progress with other people during which the solution seemed to be wrapped in deeper darkness than it ever was.”
In the decades since, scientists have been trying to trace the line back to where eels go to breed – a task made harder by the many obstacles in the eels’ way: dams, weirs, pollution, habitat loss and overfishing. A sharp decline in European eel (Anguilla anguillaThe task has become more difficult and urgent since the 1980s.
These enigmatic creatures are not to be underestimated. European eels travel between 5,000 and 10,000km (3,100 and 6,210 miles) to spawn in the sea. The larvae then return to shore and the relative safety and security of rivers.
Researchers behind this new discovery used satellite tags to track data from 21 female European Elfs as they traveled southwest from Azores, a volcanic archipelago located in the North Atlantic Ocean. This was far west of Portugal.
🕵️♀️We are helping solve a mystery which has been enthralling scientists for centuries.
❓What is the best place to spawn European eels?
😮This is the first direct evidence that European eels have reached Sargasso to spawn.
📰Learn more https://t.co/TebziSaaFI pic.twitter.com/m7fr3FTzvp
— Environment Agency (@EnvAgency) October 15, 2022
Research into eel migrations has shown that eels from all across Europe congregate around the Azores islands, before departing for their destinations. Sargasso SeaThe region of the ocean bounded by four swirling currents. It is named after its huge forests of Sargassum seaweed.
The eels were captured and tagged with satellite trackers. DNA testing was performed on the swabs and the eels were then released back into Atlantic Ocean from Azores islands in 2018 & 2019.
Six eels made it to Sargasso’s breeding grounds with their satellite trackers attached months later. Data from 15 other species of eels was also collected. The distance straightest recorded was 2,275 kilometers (1.410 miles).
“Their voyage will reveal information about eelmigration that is not known before.” “Ros Wright, UK Environment Agency’s fisheries biologist and who led the study, is Ros Wright.
It is still not clear how the eels get to the Sargasso sea, or how long their spawning period lasts.
The swimming speed of the eels in this study, which averaged 6.8 kilometers (4.2 miles) a day, and the length of their marathon journey – which takes more than a year – suggests these long-haulers need to make a very calculated migration.
Wright and his team suggested that European eels might not migrate quickly to spawn at their earliest opportunity. Instead, they may make a slow, deep spawning migration at depth. This conserves energy and lowers the mortality risk. WriteTheir published paper.
“This would allow the completion of their reproductive maturation, before they reach the spawning areas.”
“It’s amazing to know that they travel deeper than 1,000m on the way! James Maclaine, senior fish curator at UK National History Museum. Tweet. This means you’ll be plunged more than 3280 feet into the darkness.
There are still questions about how the eels navigated thousands of kilometers through open ocean to reach Sargasso.
They might be. Feel the Earth’s magnetic fieldLike Chinook salmonOncorhynchus tshawytschaThey return to the stream from which they were born. You can also sniff out olfactory cues, follow ocean currents, and monitor temperature fronts.
Although it may be some time before we unravel those threads, the new study completes our map of eel migrations. This puts the Azores in the center of conservation efforts to stop the decline of the eels.
“This discovery highlights the importance of the Azores to the life cycle for eels.” “ study author and fish ecologist José Manuel N. Azevedo from the University of the Azores.
“It will allow scientists and conservationists, to push for measures that restore eel habitats throughout the archipelago.”
The research was published by Scientific Reports.
