The U.S. Fish and Wildlife Service currently processes eDNA samples at the Whitney Genetics Lab in Onalaska, Wisconsin. eDNA results from current monitoring efforts can now be found at http://www.fws.gov/midwest/fisheries/eDNA.html.
Current standard operating procedures for all eDNA activities including field and lab work are online in the Quality Assurance Project Plan (PDF).
What is Environmental DNA?
Most of us have seen television shows where crime labs compare a person's DNA sample to DNA found at the crime scene. This gives investigators a clue as to whether or not a particular person may have been at that location at some point. While that type of DNA testing can track a genetic sample to a particular person, there are limitations on what a DNA sample can tell investigators. For example, they may not be able to tell how long a sample has been at a location or how it got there. DNA is found in certain genetic material like hair, skin and bodily fluids.
In much the same way, the Army Corps of Engineers and others have been using environmental DNA, commonly referred to as eDNA, as a surveillance tool to try to find out if DNA from bighead or silver carp is present in certain waterways. eDNA is one of the many surveillance tools used by Asian Carp Regional Coordinating Committee (ACRCC) to monitor and track Asian carp in certain waterways. However, much like the DNA comparisons used to solve crimes, there are also limitations on what eDNA can tell researchers about Asian carp.
eDNA has been used as an early detection surveillance tool since 2009. It provides information about whether Asian carp DNA is present in water samples. What it doesn't tell researchers is if the genetic material came from a live or dead fish, one fish or several, or if the eDNA may have been transported from other sources (e.g., navigation vessels or fish-eating birds). Due to the two-week sample processing time, eDNA cannot yet provide precise, real-time, information about where Asian carp might be.
So if eDNA can't answer all these questions, why use it? Asian carp are notoriously difficult to find in waterways if the population is very low. The eDNA technique is much more sensitive than other standard fishery sampling gear, and is useful for early Asian carp DNA detection and to identify distribution patterns of DNA when the fish are low in abundance. A positive eDNA result tells researchers if Asian carp genetic material is present in an area, then that area may be a good place to use other sampling tools, such as netting, to look for signs of live Asian carp. It is important to note though, that despite over two years of eDNA sampling, hundreds of hours of monitoring efforts and tons of fish harvested, only one Asian carp has been captured in the Chicago Area Waterways above the electric barriers in the Chicago Sanitary and Ship Canal.
At present, eDNA evidence cannot verify whether live Asian carp are present. Released fall of 2011, the Environmental DNA (eDNA) Independent External Peer Review (IEPR), conducted by objective panelists with technical expertise in genetics and population ecology, confirmed eDNA sampling and testing methodology is sound for detecting silver and bighead carp DNA but cannot indicate the source of Asian carp DNA (information on the size, gender, number and age of individuals present and cannot distinguish between pure silver or bighead carp and their hybrids). To view the current USACE sampling results, please visit: http://www.lrc.usace.army.mil/AsianCarp/eDNA.htm
Quality Assurance Project Plan
The Quality Assurance Project Plan (QAPP) for the Environmental DNA (eDNA) Monitoring of Invasive Asian Carp in the Chicago Area Waterway System (CAWS) outlines the detailed procedures for the planning, collection, filtering, processing and reporting of eDNA samples and will be refined periodically. This document, which has undergone a technical review by scientists at Argonne National Laboratory, is the result of collaboration between USACE biologists and geneticists and builds upon the initial protocols developed by researchers at the University of Notre Dame. Download the plan here.
The Environmental DNA (eDNA) Independent External Peer Review (IEPR) confirmed eDNA sampling and testing methodology is sound for detecting silver and bighead carp DNA but cannot indicate the source of Asian carp DNA. To learn more about the U.S. Army Corp of Engineers'completed peer review reports, please visit: http://www.usace.army.mil/Portals/2/docs/civilworks/Project%20Planning/eDNA_response.pdf
In late 2011, the ACRCC funded a study to better understand eDNA. This study is being referred to as the eDNA Calibration Study, or ECALS.