Fact Sheet:The Limitations of eDNA “Evidence”

Background:

A newly theorized and highly sensitive testing method called eDNA found inconclusive evidence of Asian carp genetic material near the Great Lakes. During a one week kill and capture operation in May designed to verify whether this genetic material indicated the presence of live Asian carp beyond existing barriers, the Asian Carp Regional Coordinating Committee killed and sorted 11,000 fish in the Little Calumet River. No Asian carp were found.

A lone Bighead carp was found during a separate routine monitoring effort in June near Lake Calumet. The presence of this single fish does not validate the continued use of eDNA.

Still, politically motivated proponents of economically devastating lock closure point to eDNA as scientific proof that existing barriers are not controlling the spread of Asian carp. There is simply no evidence that this is true, nor do eDNA test results indicate the presence of a self-sustaining population of Asian carp upriver of the barriers.

The Facts:

The ‘evidence’ of carp is based on a test that, according to one of the biologists who helped implement it, is so sensitive it is likely picking up on extremely insignificant incidences of fish – such as genetic material – rather than actual living Asian carp, much less sustaining or reproducing colonies.

US Army Corp of Engineers (USACE) Major General John Peabody noted that eDNA testing has not yet undergone a complete scientific, independent peer review, and therefore, any evidence that the electronic barrier has been breached is speculative.(February 9, 2010, “Statement of Major General John Peabody, USACE”, Subcommittee on Water Resources and Development, Committee on Transportation and Infrastructure, U.S. House of Representatives)

The continued use of eDNA to justify lock closure is not acceptable. The USACE’s most report states that eDNA, “as an emerging technology being applied in a field setting for the first time, USACE cannot conclude that water samples testing positive for eDNA evidence confirms the presence of Asian carp.” Shutting down navigation based solely on the results of a test that is self admittedly unproven in the field just doesn’t make sense.

(June 2010, Dispersal Barrier Efficacy Study: INTERIM III – Modified Structures and Operations, Illinois & Chicago Area Waterways Risk Reduction Study and Integrated Environmental Assessment, United States Army Corp of Engineers)

Only one single Asian carp has been found. It is unlikely that beyond the barriers, such limited numbers could successfully establish sustainable populations in Lake Michigan. They are unable to reproduce without long stretches of moving water and require vast quantities of plankton, both absent in Lake Michigan.

While the scientific methods used to determine the presence of carp are questionable, the economic effects of lock closure are not. Closing the locks would add $150 million to shipping costs of local businesses, and millions more in taxes, costing the region precious jobs. (June 2010, Dispersal Barrier Efficacy Study: INTERIM III – Modified Structures and Operations, Illinois & Chicago Area Waterways Risk Reduction Study and Integrated Environmental Assessment, United States Army Corp of Engineers)

The Next Steps:

The preliminary findings of eDNA testing require a multi-stakeholder discussion regarding the threat of Asian carp. No one involved in this issue wants to see Asian carp continue to spread, but a knee jerk reaction based on unreliable data is irresponsible. Members of the Asian Carp Working Group must establish specific criteria for lock closure beyond eDNA testing.

Alternatives to lock closure exist, and should be utilized to mitigate the threat of Asian carp without crippling the region’s economy. Continued costly and disruptive closures based on speculative eDNA results distract stakeholder from working towards a long-term, comprehensive solution to stop the spread of Asian carp.