By Sarah Gross
CHICAGO -- The U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service and U.S. Geological Survey, released an interim report for the Asian Carp Environmental DNA Calibration Study, today, which is a three-year study funded through the Great Lakes Restoration Initiative, as scoped by the Asian Carp Regional Coordinating Committee Asian Carp Control Strategy Framework.
"The purpose of [the Environmental DNA Calibration Study] is to improve the understanding and interpretation of Asian carp environmental DNA results, so we can refine and make this relatively young monitoring tool the most effective to detect live Asian carp presence," said Kelly Baerwaldt, U.S. Army Corps of Engineers Environmental DNA, or eDNA, program manager.
Initial Environmental eDNA Calibration Study, or ECALS, efforts within this report focus on identifying alternative sources of eDNA beyond a live Asian carp, whereas marker development to aid in detecting the specific species and calibration experiments that look at factors that may influence the detection, degradation or persistence of DNA will receive greater attention in 2013.
Among preliminary findings:
• Storm sewers, fisheries sampling gear, fish-eating birds, dead fish carcasses, barges, and sediments may contribute to a positive eDNA detection without a live fish being present.
• DNA can stay on these sources for a numbers of days.
• Tagged-bird studies show large variations in bird movement and consumption of Asian carp in the wild, which may lead to positive detection of Asian carp eDNA in bird feces.
• Shedding rates of DNA from Asian carp were not affected by different temperatures or flow rates of water.
• DNA from Asian carp sperm can be detected for over two weeks after release from an Asian carp.
The agencies will host a stakeholder conference call Feb. 26 at 10 a.m. (Central) to answer questions regarding this report. Call-in information is USA Toll-Free: 877-336-1839, USA Caller Paid/International Toll: 636-651-0008, Access Code: 8506361, Security Code: 0000.
"Partnership is key in the successful planning, research and implementation of a comprehensive Asian carp prevention plan, and we are confident we have the right people on board to thoroughly explore eDNA uncertainties," said Jon Amberg, U.S. Geological Survey researcher.
The ECALS Team will continue to investigate alternative sources and pathways for eDNA detections beyond a live fish; examine how environmental variables such as light, temperature and water velocity impact eDNA detections; explore the correlation between the number of positive samples and the strength of the DNA source, develop more efficient eDNA markers to cut the sampling processing time in half and model eDNA transport specific to the Chicago Area Waterway System.
"As members of the [Asian Carp Regional Coordinating Committee], we are committed to preventing Asian carp from becoming established in the Great Lakes through participating in extensive monitoring of the waterways and additional research on eDNA," said Kurt Schilling, U.S. Fish and Wildlife Service Midwest Region hatchery supervisor.
The report, executive summary and fact sheet are posted on http://www.asiancarp.us/ecals.htm.
Asian carp DNA surveillance programs determine the presence of Asian carp by detecting the genetic material (DNA from shed cells in slime, feces, urine, etc.) in water samples to correlate DNA detection with the possible presence of invasive silver carp or bighead carp.