Roads and dams put European eels at risk, scientists offer strategy to save them

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.

An international team of scientists have put forth recommendations, published in Global Ecology and Conservation,  for conservation strategies that could save the species from extinction including improved population monitoring, restored freshwater habitats and stronger international collaboration. The team includes FIU biologist Stephanie Januchowski-Hartley.

“European eels are highly endangered because the ecosystems that they depend on are highly modified by people,” Januchowski-Hartley said.

Though often overlooked, the European eel plays an important role in freshwater ecosystems, and its loss could disrupt food webs and the balance of other wildlife.

“Losing any species in an ecosystem means that can lead to instability in the ecosystems that it belongs to,” Januchowski-Hartley said.

The conservation priorities were identified using the Delphi technique, which brought together more than 50 researchers and resource managers to build consensus on the most urgent conservation needs. One of the biggest threats facing European eels is human infrastructure. Culverts, structures built beneath roads and bridges to allow water to flow through, are often not designed to accommodate fish movement. When poorly designed, they can block eels from reaching the freshwater habitats they need to grow and survive.

“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. Researchers say protecting the species will also require stronger monitoring efforts and support from policymakers.

Januchowski-Hartley said eel populations are difficult to track because countries often collect data differently, making collaboration and investment essential to understanding where populations are declining and which conservation efforts will have the greatest impact.

“To monitor takes a lot of resources, so it’s not often something that politicians want to invest money in,” Januchowski-Hartley said.

Januchowski-Hartley focuses much of her research on conservation decision-making — connecting ecological, social and economic data to optimize strategies that manage species, habitats and services. She said she hopes this latest study will encourage governments and conservation organizations to invest in long-term monitoring, habitat restoration and international collaboration.

“Even if we don’t all agree 100% on something, you can find a level of consensus on the key and most important things,” she said.