Lessons from the Asian Carp Hearing: Federal Officials Refuse to Admit that They Failed to Stay on Top of the Invasion

Last week bighead and silver Asian carp – and the federal and local agencies charged with ensuring that they do not invade the Great Lakes – were finally hauled into court.  The State of Michigan, joined by four other Great Lakes states, has brought a lawsuit against the Army Corps of Engineers and MWRD seeking both short-term measures such as a temporary closure of the navigational locks connecting the Chicago Area Waterway System (CAWS) to Lake Michigan, as well as an expedited review of permanently separating the Great Lakes and Mississippi River, to prevent invasive species from using the CAWS as a highway to travel in both directions.  NRDC is not a party to the lawsuit, for a variety of reasons, but I attended last week’s hearing as a highly interested observer.

On the first day of the hearing, Michigan called to the stand Notre Dame biologist David Lodge – the scientist who, more than anyone else, has highlighted the urgency of the Asian carp threat through his work on behalf of the Army Corps using environmental DNA (eDNA) monitoring techniques to detect the presence of Asian carp beyond the electric fish fence that Army Corps is relying on as its primary means of stopping the fish’s advance. 

Lodge’s testimony made clear that, in May 2010, he had told federal and state agencies not to spend $1.5 million on poisoning the Calumet River below the O’Brien Lock, because based on his most recent evidence, they were not likely to find Asian carp there.  The agencies poisoned anyway, then sent out a series of splashy press releases trumpeting the fact that they didn’t find any fish.  What the agencies failed to mention in their press releases is that the eDNA results were at all times consistent with what was found through the fish poisoning – eDNA tests taken the same day as the May 2010 fish poisoning came back negative – and not only that, but that as it turns out, the agencies acted against the recommendations of the independent scientists with whom the agencies themselves had contracted because they needed better information about where the Asian carp have advanced within the CAWS.

One of the exhibits that Michigan introduced into evidence in the trial was a never-before-published report by David Lodge and his team from June 2010, which had summarized for the Army Corps and other agencies the modeling that the Lodge team had done to determine how quickly Asian carp had advanced up through the Mississippi and Illinois Rivers toward the CAWS.  The Army Corps and U.S. Fish & Wildlife Service had concluded that Asian carp invasion had stalled in the Dresden Pool, approximately 10 miles downstream from the electric fence.  The Lodge team concluded, however, that even if you discount the eDNA results, Asian carp had moved toward Lake Michigan far more quickly than the Army Corps had thought:

We conclude that Asian carps should have been testing the electric barrier as early as 2006, yet with no detections using net and electro‐fishing equipment, the hypothesis of a stalled invasion front was plausible.  However, using a species specific environmental DNA surveillance approach, which detects the presence of Asian carp from collected sloughed fragments of DNA suspended in the water column, new detections of Asian carp were found at and above the electric barrier in 2009. These new detections correspond to where dispersal modeling would predict the invasion front to be.

In other words, the Lodge team’s statistical analysis concludes that the pattern of positive eDNA results in the CAWS is consistent with the rate of the fish’s advance toward Lake Michigan.  This statistical analysis doesn’t depend on the validity of the eDNA results, as the Lodge team performed one statistical analysis with the eDNA results included, and another statistical analysis that did not incorporate any eDNA results, and the results are remarkably consistent. 

Perhaps the most shocking conclusion from the Lodge team’s modeling is that Asian carp were present at the entry point to the CAWS as early as 2006 – and the Army Corps and U.S. Fish & Wildlife Service, who were relying on traditional detection methods to look for them, had no idea that they were there. 

Why do the traditional detection methods not work in the CAWS for detecting Asian carp?  According to the Lodge team’s report,

it is also known that electro‐shocking is much less effective in deep water, the primary habitat in the CSSC and that Asian carps are particularly difficult to capture in low abundance using nets.

Don’t just take David Lodge’s word for it, though.  The Lodge team relies on the Government’s own Asian carp expert, Duane Chapman with the U.S. Geological Survey, citing to a 2007 book that Chapman authored along with other Government scientists.  Chapman also testified at last week’s hearing, clearly stating that traditional methods do not work well for detecting Asian carp in low numbers, and that Lodge’s eDNA methodology is a more reliable tool.

And yet, despite all the evidence that traditional detection methods don’t work, officials with the Army Corps and U.S. Fish & Wildlife Service refuse to admit it. 

At the hearing, Charles Wooley, the Deputy Regional Director for Fish & Wildlife, testified that Duane Chapman is an “excellent scientist” but refused to agree with Chapman’s view the eDNA is a more reliable detection method for Asian carp than traditional methods, which Wooley described as “tried and true.”  Wooley claimed that he knows that traditional methods will work in the CAWS (where Asian carp are likely present in low numbers) because they work downstream in the Illinois River system (where Asian carp are known to be present in abundance).  But how is that logical?  This is what Asian carp populations look like where they are established in abundance in the Illinois River:

In those areas where they are established, Asian carp outcompete native species and take over the waterway.  Of course Fish & Wildlife is able to fish out carp from waters that are infested with them!

Wooley refused to recognize the obvious difference here:  just because traditional fishing methods can pull a significant number[*] of Asian carp out of the water in areas where they are abundant does not mean they will be effective or reliable at finding small numbers of fish – the proverbial “needle in the haystack.”  That’s exactly why the Army Corps paid the Lodge team to develop eDNA in the first place – because they needed a better, more sensitive method to find those needles.

But now that eDNA is available, the Army Corps and Fish & Wildlife refuse to act aggressively on the results.  It seems like the agencies just don’t want to admit that they are wrong…  and that for years they have spent millions of dollars on an electric barrier that hasn’t worked, fish poisonings of historic proportion, and detection methods that haven’t stayed on top of the invasion.  David Lodge’s testimony runs counter to what the agencies have been selling to the people of the Great Lakes region, which might just be broken goods (or a defective fence anyway).

So instead of embracing the new information provided by eDNA, the agencies keep throwing good money after bad by continuing to rely on the same old thing.  Meanwhile, there is no eDNA testing currently being undertaken in the CAWS, while the Army Corps does its own “peer review” of the technique.  Much is made of the fact that the eDNA method has yet to be fully peer reviewed – but the traditional methods have never been peer reviewed either with regard to their effectiveness at detecting Asian carp that are present only in small numbers.

Last week John Goss was appointed to the position of “Asian Carp Director” at the White House Council for Environmental Quality.  By all accounts, John is a good man, a true public servant, and an excellent choice for his new position.  But will any of this nonsense change as a result of his appointment?  Only time will tell…  but the Great Lakes may not have much time left.

CORRECTION

[*]  The original version of this post stated that, in waters below the barrier, where Asian carp are present in abundance, traditional methods are able to pull a significant "percentage" of Asian carp out of the water.  That was an imprecise choice of words on my part.  I have no idea what the percentage is, only that the traditional methods are able to pull a significant "number" out of the water.  The question of what percentage of Asian carp are caught by traditional methods was actually a point of contention at the hearing.  Charles Wooley testified that he did not know the percentage, and did not need to know it.  Other scientists, including the Lodge team, have suggested that, from what we do know about the percentage caught, it's likely very low, perhaps even as low as 1% -- meaning that, in areas where the population is not dense (such as in the leading edge of the invasion), the actual catch is likely to be zero or close to zero.  The only way to know for sure is to derive, through further study, a credible estimate of the "catch per unit effort" (CPUE) of using traditional methods to detect Asian carp.