Roads, dams and other infrastructure built to make life easier for people have unintentionally made survival harder for another form of life — critically endangered European eels. “European eels are highly endangered because the ecosystems that they depend on are highly modified by people,” Januchowski-Hartley said. One of the biggest threats facing European eels is human infrastructure. “The road is designed with traffic in mind, and the infrastructure underneath is designed with water flow in mind, but it’s not designed with fish in mind,” Januchowski-Hartley said. The work to conserve European eels does not stop at infrastructure.