The U.S. Geological Survey (USGS) is conducting market research to identify businesses capable of providing a specific in-situ benthic algae measurement instrument, as detailed in the attached salient characteristics. This is a sources sought notice for planning purposes only and is not a request for quotes or proposals. Responses, consisting of a brochure or technical specifications, must be submitted via email to aberry@usgs.gov. The required instrument must measure benthic algae on substrates in waterbodies without sample preparation, with specific capabilities for measurement range, resolution, and differentiation of algae types.