Below is some information on the DNA testing that Carptracker referred to. The University of Dotre Dame in IN has been conducting the testing, and back in June, our club helped provide them with a list of sites on the Des Plaines river where the Asians could be found.
Congrats to the researchers who now have another viable tool at their disposal. 
ago Sanitary and Ship Canal – Aquatic Nuisance Species Dspersal
Environmental (eDNA) Detection
Overview:
Fishes, including Asian carp, release DNA into
the environment in the form of mucoidal secretions, feces, and
urine. DNA degrades in the environment, but this process is
not instantaneous, and DNA can be held in suspension and
transported. The presence of species can be detected by
filtering water samples, and then extracting and amplifying
short fragments of the shed DNA. In contrast to other
surveillance methods, the environmental DNA (eDNA)
method does not rely on direct observation of Asian carp to
evaluate presence.
Scope:
Laboratory and preliminary field studies confirmed
that eDNA from Asian carps can be detected in 1 liter water
samples from sites with high, moderate, and low densities of
carp (see figure). Water samples are collected in the field and
filtered in the lab. DNA is extracted from the filtrate, and any
DNA from bighead and silver carp is amplified with PCR
using genetic markers that are unique to bighead and silver
carp. The eDNA approach uses standard genetic
identification methods in a novel application--the extraction of
low concentrations of DNA from water sampled in the field
that allows for species-specific detection.
The objectives of this study are to locate the invasion front
using the eDNA methodology and to compare the results with
other surveillance approaches. We will do this by completing
a longitudinal study of CSSC, sampling both the main-stem
and different microhabitats (pools, backwaters, side channels)
as we expect eDNA to accumulate in certain areas resulting in
an increased probability of detection. In addition, we will
increase the volume of water sampled as we sample around
the putative invasion front, as greater volumes may be needed
at low fish densities.
The data collected will allow an evaluation of detection probability
for variable water volumes and microhabitats that can be used to
inform improvements in the long term monitoring program. Data on
environmental covariates such as flow, pH, and temperature will also
be collected at each site to test how these variables influence
detection rates.
How will this improve our current monitoring?
The eDNA approach to surveillance will allow greater geographic
coverage throughout the CSSC and connected waterways, and should
be more sensitive at detecting low abundance of fish than the methods
currently employed. While adult carps are the most likely to be
detected with existing techniques, eDNA will be able to detect
juveniles as well as adults. Water sample collection can be
accomplished from boats, bridges, shorelines, in between the barriers,
and in habitats that are difficult to sample with the current approaches
(such as shallow channels of the Des Plaines River or deep sections of
the CSSC where electro fishing can be ineffective and high boater
traffic precludes the application of nets).
To calibrate the eDNA approach against current methods (e.g.,
electroshocking), we will conduct eDNA analyses on different
volumes of water taken from locations where current surveillance
methods are employed. Improvements over current methods would
then be achieved by routinely sampling larger volumes of water than
those necessary to match detection limits of the current methods.
To further increase the usefulness of eDNA in the surveillance
program, quantification of detection errors in experimental ponds or
flumes with known fish abundance would be necessary, but that is not
proposed here.