A recent study, with its roots going back to 2004, has showed promising news that Elwha River steelhead trapped for a century miles from the Strait of Juan de Fuca by the Elwha River dams have managed to maintain their natural genetic diversity during that time and are able to return to their old natural cycle of returning to the sea.
“The genetic diversity harbored behind the dams suggests that diversity was important for their natural resilience, or their ability to adapt to changes such as dam building or removal,” said Alexandra Fraik, a doctoral student at Washington State University. Fraik did the work as a National Science Foundation graduate research internship program fellow with NOAA.
“Additionally, we see recolonization of steelhead that appear to descend from populations that were both below and behind the Elwha River dams rapidly following dam removal,” Fraik said.