Cooperative Agreement for affiliated Partner with Great Rivers Cooperative Ecosystem Studies Unit

The USGS is offering a funding opportunity to a Great Rivers CESU partner for research to assess the efficacy of using in-situ fluorometry for detection of milt (seminal fluid) from invasive carp in rivers downstream from spawning sites. Invasive carp–bighead ( Hypophthalmichthys nobilis ) silver ( H. molitrix ), grass( Ctenopharyngodon idella ), and black ( Mylopharyngodon piceus ) carp–are native to Southeast Asia and have spread throughout much of the Mississippi River Basin since their escape from private, wastewater, and aquaculture ponds in the 1980s. Technologies allowing for early detection of these species, especially evidence of natural reproduction, are needed by state and federal agencies throughout the Great Lakes and Mississippi River Basins to control the spread of invasive carp and assess risk to uninvaded waters. Natural resource managers have generally relied upon labor-intensive ichthyoplankton sampling by boat crews to determine if invasive carp are spawning in a river. While these samples can provide direct evidence of spawning, they require crews to be on the water sampling in the right place and right time during a spawning event. The discrete samples collected using traditional sampling methods are generally spatiotemporally sparse due to limited resources. Recent deployments of streamside environmental DNA (eDNA) autosamplers have shown promise in detection of spawning activity ( project webpage ). However, the equipment and analyses are costly, the system has limited sampling capability, results are not available in real-time, and eDNA methods used cannot currently discern the presence of milt or eggs from that of adult fish.