ECALS teams use eDNA research to curb carp invasions

Published March 19, 2014
Dr. Martin Schultz, EL research environmental engineer, serves as project team leader in developing, organizing, and executing work under the Environmental DNA Calibration Study (ECALS) probabilistic modeling objective.  This research focuses on developing methods to make probabilistic statements about the potential sources of eDNA detected in monitoring samples and the presence of live fish in the Chicago Area Waterways System

Dr. Martin Schultz, EL research environmental engineer, serves as project team leader in developing, organizing, and executing work under the Environmental DNA Calibration Study (ECALS) probabilistic modeling objective. This research focuses on developing methods to make probabilistic statements about the potential sources of eDNA detected in monitoring samples and the presence of live fish in the Chicago Area Waterways System

While bighead and silver carp seemed useful when first imported in the 1970s to control  phytoplankton and macrophytes in fish ponds and wastewater areas, these species escaped and exploded into now-detrimental super-sized fish. The high-vaulting creatures are real and dangerous to fishermen and water skiers, as well as harmful economic culprits.

U.S. Army Engineer Research and Development Center (ERDC) scientists joined other conservation teams in 2011 to formulate research rescue.

Environmental Laboratory (EL) team members continue the fight to curb the invasion of these manic feeders and leapers, employing detection methods to locate their environmental deoxyribonucleic acid (eDNA), referring to the DNA that has been shed from an organism and is still present in the environment.

Recently, biologists have been using eDNA to determine whether invasive species are present in water, even when no other evidence suggests that the species is present.  It is a weapon in the war against advancing carp.

Bighead carp and silver carp are invasive fish species that are abundantly present in the Mississippi River Basin and threaten to invade the Great Lakes via the Illinois River and the Chicago Area Waterway System (CAWS). 

“They undermine food webs and outcompete native fish populations in the habitats where they become established,” said Dr. Martin Schultz, team leader in developing, organizing, and executing work under the Environmental DNA Calibration Study (ECALS) probabilistic modeling objective, which focuses on developing methods to make probabilistic statements about the potential sources of eDNA detected in monitoring samples and the presence of live fish in the CAWS.  This will enable natural resource managers to make decisions about what actions to take in the CAWS considering the information being provided by eDNA monitoring programs.

He explained the difference between the ECALS team and the ECALS Probabilistic Modeling project team.

 “ECALS is the larger umbrella that includes the ECALS probabilistic modeling effort as one of several initiatives. ECALS is an interagency study with participants from the U.S. Army Corps of Engineers (USACE), U.S. Geological Survey (USGS), and US Fish and Wildlife Service (USFWS).   ECALS was funded in late 2011 to improve the application of eDNA detection and monitoring methods and to improve the ability to interpret eDNA monitoring data,” Schultz said. 

                                                        Detections beyond live fish

According to their website (http://www.asiancarp.us/ecals.htm), “the purpose of ECALS is to improve the application of eDNA methodology to assess and manage uncertainty.”  ECALS is identifying what sources of eDNA other than a live fish may be contributing eDNA to the system, developing more sensitive genetic markers for detecting Asian carp eDNA, investigating ways to increase the efficiency of processing eDNA samples in the laboratory, estimating eDNA degradation rates and the influence of environmental conditions on those rates, developing a hydrodynamic model to simulate eDNA fate and transport, and developing a probabilistic model for making statistical inferences about eDNA sources and the presence of live fish. 

“The intent is that all entities using eDNA as a monitoring tool will be able to use this information to refine their own monitoring and management programs.  The results will inform current eDNA sampling strategies and will make the sampling more efficient and allow for more informed interpretation by managers who are considering taking management actions in response to eDNA monitoring data in the CAWS,” Schultz said.

                                                    Carps northern invasion routes

Schultz said that Dr. Edmond J. Russo, formerly EL division director and now with the Galveston District, organized the ECALS team and development of the initial ECALS proposal as the carp’s destructive trek northward became apparent. 

The team went into action against these invasive fish in the Mississippi River Basin as the two carp species threatened to invade the Great Lakes through the Illinois River and the CAWS.

“The leading edge of the invasion is presently believed to be in the Illinois River, approximately 55 miles downstream of Lake Michigan.  Several years ago, USACE constructed an electric fish barrier at Romeoville, Ill., approximately 30 miles from Lake Michigan, to help prevent Asian carp from reaching the Great Lakes, or at least to greatly reduce that probability.   In cooperation with the University of Notre Dame, USACE began collecting water samples upstream from the CAWS barrier in 2009, testing the water samples for bighead carp and silver carp eDNA. 

“The purpose of the eDNA monitoring program was to determine whether or not bighead and silver carp were present upstream of the barrier, which might suggest the fish had penetrated the electric barrier.  USACE gradually took over responsibility for collection of eDNA monitoring samples, and ERDC began processing those samples in 2010,” Schultz said.

In addition to the eDNA monitoring program, the Monitoring and Response Workgroup, led by Illinois Department of Natural Resources, also implements a conventional fisheries surveillance program.  This program deploys electro-fishing boats and nets at fixed and randomly selected sites to determine the numbers and types of species present.

“If these fish do become established in Lake Michigan, they could harm native fish populations.

Efforts to prevent Asian carp from colonizing Lake Michigan focused on the CAWS, because it is the principal hydrologic connection between the Mississippi River Basin and Lake Michigan.

According to the ECALS Milestone Report, monitoring crews logged over 9,600 hours from 2010-12 collecting samples at fixed and randomly selected sites throughout the CAWS upstream of the barrier. One bighead carp was captured during the course of fixed site monitoring in June 2010; however, no bighead or silver carp have been captured as part of this conventional sampling program since then.                                       

                                      Team member expertise from two Vicksburg Labs

While the umbrella ECALS team formed in 2011, the group of scientists and engineers that is working together to develop the ECALS probabilistic model began meeting in May of 2013 with expertise in probabilistic risk analysis, genetics, fisheries, water quality, sediment, fate and transport modeling, hydrodynamic modeling, model calibration and ornithology. 

EL’s team members include Dr. Richard F. Lance, Dr. Heather Farrington, Dr. Carl F. Cerco, Mark Noel, Dr. David Smith, Dr. Michael Guilfoyle, and Dr. Trudy Estes. CHL’s experts on the team are Dr. Brian Skahill, Dr. Sung-Chan Kim, and Dr. Phu Luong.

Schultz noted the objective as “developing a model that will allow natural resource managers to use results from eDNA monitoring efforts to help assess the probability that live fish may be present in the water body where monitoring samples were collected. 

“In the course of working towards the probabilistic modeling objective, the team will also be able to integrate much of the knowledge and insights that have been gained from various other ECALS initiatives.  Activities should be completed by the end of September, 2014,” Schultz said. 

Helping control these monster fish serves as another prime example of ERDC’s innovative solutions for a safer, better world.