European investigators have struck down organized gangs of glass eel smugglers in a joint operation.
A total of 49 people were arrested, said Europol on Friday in The Hague.
After the corona travel rules were lifted, the smuggling of the endangered fish increased sharply.
According to Europol, investigators checked air travelers in 24 countries from November to June.
More than 1,200 kilograms of young European eels were confiscated, worth around 1.9 million euros.
The very young eels are called glass eels because they are almost transparent.
The European eel is under special protection as stocks have been reduced by 90 percent.
Trade in glass eels is one of the most lucrative illegal trades in protected species, according to Europol.
Europol estimates the profits at up to three billion euros a year worldwide.
Targeted actions against smuggling could help prevent the extinction of eels.
Organized gangs were behind the smuggling, transporting the young fish in hand luggage from Europe to Asia.
They had developed methods to keep the eels alive for 48 hours.
In Asia, the glass eels would then be released into fish farms and later traded worldwide.