File:July 26, 2012 Studying impacts to bottom habitats (7932041092).jpg

Here, a rainbow star (Orthaserias hoehleri) is beneath the transect tape used by divers to ensure the same areas are compared year to year off the mouth of the Elwha River.

The removal of the Elwha River dams will affect marine habitats in the Strait of Juan de Fuca, from the flow and deposition of sediment that accumulated behind the dams for nearly 100 years. The newly released sediment can have a variety of effects including burial, inhibition of aquatic reproduction, light reduction, damage to animal gills and filter feeding structures, and alteration of species interactions with their different tolerances and responses to the sediment. Elwha nearshore communities will continue to be surveyed during and after dam removal. Measuring community responses to short and long term changes offers an unprecedented opportunity to gain insight relevant to managing these important marine resources.

For more information, see: www.usgs.gov, www.usgs.gov/elwha,