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Smelling Fishy: my Asian carp “interview” with the Trib’s Dennis Byrne

Henry Henderson

Posted December 10, 2009

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Chicago Tribune columnist Dennis Byrne mused about the Asian carp crisis that has been a public policy and media focus in recent weeks.  From his tone, Byrne seems to think that concern about the invasive fish's advance on the Great Lakes is overblown and that calls to temporarily close locks on the waterways leading to Lake Michigan from NRDC, editorial boards throughout the region, a range of elected officials, and other Great Lakes advocacy groups  are specious (or as he terms it, "crimp a world engineering marvel that made Chicago what it is because some fat, ugly carp are swimming in it").

This is a complicated issue and debate is needed, but I am surprised that a business savvy guy like Dennis Byrne would pretend that he doesn't understand why emergency measures are needed to meet an imminent threat to a multi-billion dollar fishing industry and the largest body of fresh water in this hemisphere. Still, he does ask some interesting questions that I thought I'd take a stab at answering.

So, I guess this is my virtual interview with Dennis Byrne (the questions are his, straight from the column, though in a different order):

BYRNE: Hey, what's the matter with carp, anyway? Regarded here as "trash fish," they're food in Europe and Asia. It was the revered Izaak Walton who described the carp in his "The Compleat Angler" as a fine eating fish: the "Queen of Rivers, a stately, a good, and a very subtle fish."

HENDERSON: Let’s be specific. We are not talking about common carp, which are eaten in many places. The critters in question here are the silver and bighead carp. I must admit I’ve never dined on them, but I've always heard that they taste horrible. Worse, they have interlaced, "floating bones" that make them a nightmare to eat.

While the fish are not good to eat, they are very good at eating. They can get up to 100 pounds in size and eat 40% of their body weight daily. They are too big for most native species to prey on, so as a result the Asian carp simply out-eat and out-breed the rest (and the results are abundantly clear in sections of the Illinois River where the carp now represent 90% of the total biomass!). In the Great Lakes system, already taxed by influxes of other non-native species, it could be the last straw.

BYRNE: Any moment now (as of this writing), a decision will be made by the Obama administration whether to shut the locks "temporarily," whatever that means. But before it's done, the audacious might have a few questions:

What is the impact, even of a short shutdown? The Great Lakes fishing industry isn't the only one with an interest. More than 14.6 million tons of commodities annually move through the canal, according to the American Waterways Operators. Iron and steel from northern Indiana, gravel and building materials for Chicago are among the commodities whose Great Lakes shipment would be halted or would have to be shipped by alternative, more costly methods.

HENDERSON: Dennis, this is a great question. First though, it is worth noting that the Great Lakes fishery is not a trivial business---it is valued at $7 billion. And don't forget the multi-billion dollar Great Lakes tourism and recreation industries either; they will be significantly affected, too.

But your point about the movement of goods is an important one. No doubt barge traffic would be affected by a temporary emergency closure of the locks. But the implication that commodity movement would be shuttered is overstated. Waterborne transit only represents a small percentage of the total goods moved through our region. And let’s not forget that Chicago is the nation's transportation nexus with massive resources to move goods by truck and rail. The commodities will still move. And move efficiently.

BYRNE: Does slowing or stopping the flow of water into the system affect water quality, public health and flooding? The Army Corps says it might.

HENDERSON: They are right. A long-term closing of the locks would eventually lead to some flooding and backup in the canal. And that's why nobody is suggesting permanent closure of the locks. We need to take some immediate action to prevent these fish from establishing themselves in the Great Lakes. Closing the locks temporarily will give us a bit of breathing room while the bigger engineering challenges of a permanent solution can be re-examined.

BYRNE: The carp are just one of a long list of "invasive" species that over the years purportedly threatened the Great Lakes ecosystem and fishing industries. Somehow, they have survived. Could the dire predictions about the carp be overstated?

HENDERSON: I am not sure why you put invasive in quotes, but you are right, the carp are just the latest in a long line of species that have been introduced to this ecosystem. State and federal regulators are in complete agreement with biologists, scientists, and environmental groups who all recognize the potential damage that Asian carp could wreak on the Lakes. But the important thing to remember is that this newest wave is not the last. Invasive species will keep on coming and coming. Until we slam the door, this problem will not go away---hence the long-term need to separate the Mississippi River and Great Lakes basins.

As for the survival of native species, the very lucrative fishing industry based on lake trout was destroyed over 100 years ago when the invasive Lamprey entered the Great Lakes through eastern canals and wiped out the trout. The Lampreys are still with us, costing millions of dollars to manage annually, and will never be eradicated. The Asian Carp present an even more dangerous threat---not just to the present sport fishing industry but to the quality of Great Lakes water itself.

I would point you to an excellent article the Tribune’s James Janega wrote about the shocking transformation that zebra and quaggamussels have had on Lake Michigan. When the problem first came onto the scene, we were worried about the impact these critters were having on municipal water intakes and infrastructure which now costs Great Lakes economies over $200 million dollars annually. But, as Janega showed, we have not seen the true costs of this infestation yet. The ecological changes brought on by the mussels have changed the quality of the water in Lake Michigan. Many researchers think that they are creating an environment at the bottom of the Lake that will breed pathogens like E. coli that could take a significant health toll on humans and marine creatures. The Asian carp feed in similar fashion to the mussels and would likely speed up this transition that could impact drinking water supplies for over 40 million people.

BYRNE: This is shaping up to be a regional conflict, as controversial as Chicago's diversion of Great Lakes water has been for the last century. Don't we deserve a better airing of the issues (not the least of which is the impact on Chicago's economy) and choices before the lock gates slam shut, even temporarily?

HENDERSON: Absolutely. We have been calling for a better airing of the issues in the form of a public, transparent, comprehensive analysis of how best to deal permanently with the problems presented by the canal and the threats illuminated by this carp saga---rather than the narrow, herky-jerky, ad hoc noodling on the margins that the Army Corps of Engineers, Coast Guard, State of Illinois and Metropolitan Water Reclamation District have given us to date. Any durable, long-term solution will require enlightened leadership to create a plan for a modern, more sustainable transportation and water management infrastructure for Chicagoland.  Think of it as a Burnham Plan for the 21st Century.

But make no mistake; we've already had lots of time to look at the issues. This has been a slow-motion tragedy that requires emergency action now to buy us the time we need to solve this problem effectively. Sadly, the folks responsible for heading off this problem at the pass failed to act with the necessary urgency. That’s why it is frustrating to call for immediate action to temporarily close the locks and put physical barriers on the unprotected waterways. This was once preventable, but now we are left without choices in the short-term.

The good news is that this also presents an incredible opportunity in the longer term. I disagree with your assertion that the canal “made Chicago what it is.” It has been our ability to identify real problems, plan creative responses and leverage the dollars and sweat to implement solutions that has made Chicago what it is. The energy to meet new problems emerging from new situations has always accompanied the "I Will" spirit of Chicago. And that is why I find the “un-Chicago” response to this debate so maddening. Since when did we get so fatalistic? Why do we have to accept century-old solutions? We can do better than a defensive belittling of people who point out that (a) we have problems, which (b) can be fixed, thereby (c) improve our lives.

We find ourselves at another point where the status quo is untenable. The Asian carp are a clear sign that we need to re-establish natural barriers between the Mississippi and Great Lakes to safeguard 1/5 of the world's fresh water and the region's most precious asset. But this crisis is also a clarion call to tackle the infrastructure problems that have grown more and more vexing in recent decades as we have remained reliant on century-old structures. It is time to summon Chicago’s “I Will” spirit and think big about our region's redevelopment.

Great interview! Thanks Dennis. By the way, I have  a few questions for you:

  • What happens if a kid gets whacked by one of these whopping fish on Oak Street Beach? Far fetched? Not really; similar things have happened on other lakes. The fish's penchant for leaping out of the water when startled makes me wonder what effect this problem could have on tourism, which fuels more and more of the Chicago and the State of Illinois economies (Statewide $30.8 billion was spent by visitors in 2008, yielding $2.1 billion in state and local taxes and generating 303,500 jobs according to the Chicago Convention and Tourism Bureau). There's no doubt that the Lake is a big part of the attraction.
  • Municipal governments have been footing the bill for invasive species to the tune of, literally, billions of dollars for decades now. Shouldn't the externalized costs of waterborne shipping, whether by barge or cargo ship, be represented in a true cost accounting of our options?
  • Dennis, in the column, you write: “Apparently, the last 30 years of erroneous and invented warnings about climate catastrophes, resource depletion, pandemics, overpopulation and other Malthusian alarms have taught us nothing about losing our heads." Climate change denial? Really? You and the Chicago Tribune can do far better than discounting 30 years of critical scientific research, advocacy, and work to protect quality of life for all Americans.
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Duane ChapmanDec 13 2009 04:25 PM

I didn't want to put this in an open comment, but there is no contact info to send a private email. I would just like to inject some fact-checking.
1)Taste is a matter of personal preference, but in blind taste tests, Asian carps have done very well. These are not like common carp. They have intramuscular bones in the filets, but the bones are NOT "interlaced". In fact, you can see me actually cutting between the bones here:
I am a scout leader, and our scouts often prefer the carp to catfish.

2)The 40% of their body weight number comes from a fish about 4" long, in a situation where there was plenty to eat, in an aquarium. Adult fish in an oligotrophic system won't eat 40% of their body weight daily, I'm pretty sure. Doesn't mean they won't be a problem, but the 40% number is misleading.
3)I'm pretty sure there is no river stretch where Asian carps represent 90% of the biomass of every living thing. First off, no one has ever done an estimate of relative biomass of organisms in a Great River. Maybe if you got right in the middle of a dense spawning aggregation you could reach 90% of the fish biomass as Asian carp. But that would be like saying 90% of the fish in a school of shad are shad. And there are no reaches of the Illinois River or anywhere else in the USA where sportfishes have been shown to be nearly eliminated because of Asian carps. In fact, substantial sport fisheries persist everywhere the carp have invaded, and in most cases if there has been a decline in catch it has been minor - there are no studies that point out huge declines in the population of other species, but some native species are skinnier. I believe that will translate later into to population issues at least for those limited species, but that is speculation. We do have a disaster here in the central United States, and carp in the Great Lakes could turn out to be another disaster, in a place where the value of the fishery is much, much, higher. But 90% of the biomass anywhere is just not correct.

There are lots of good reasons to want to keep the carp out of the Lakes. I just want to keep the facts in the debate correct.

Josh MogermanDec 14 2009 04:17 PM


You make some great points about conflicting information out there on this subject. The interlaced bones reference comes up in many places, such as this one from Illinois' Department of Parks and Recreation:

As for the biomass and feeding numbers, they come directly from USEPA and the Asian Carp Rapid Response Workgroup---the people tasked with spearheading this fight. Here's a reference to their filtering:

The biomass reference (that in portions of the Illinois River the carp represent 9 out of every 10 pounds of living creatures) sounds outlandish, but has been a staple of the federal talking points on this issue. And its less shocking when you see the photos of flood aftermaths on the river where massive amounts of fish are stranded on the banks---almost exclusively Asian carp.

I am sure that we certainly agree that the fish represent an unacceptable threat to our nation's most important fresh water resource. We need to address the problem

Duane ChapmanDec 16 2009 08:58 PM

What you say is true - the 90% of the biomass in the Missouri River number has been a major talking point. Unfortunately, that doesn't make it correct. The link you provided went to the bones of contention page on eating fish. I think you mean this one:
You will note that the text says that in a fish kill in a backwater in Missouri "revealed that 90% of the fish were Asian carps." That is a different thing from "90% of the biomass of every living thing in some parts of the Illinois River is carp", (wrong state, for one thing) and in any case the site is somewhat misleading. I am familiar with that particular event, which was due to an oxygen sag. Asian carps are not like common carp. They are more sensitive to oxygen depletion than many other fish, so it is not clear that they represented 90% of all fish (catfishes probably did not die, nor gar, nor the also-invasive common carp) by number, and there is no mention of the relative weight of those fish, which were mostly small. And in any case it does not represent non-fish biomass.

Duane ChapmanDec 16 2009 09:28 PM

Regarding the AC rapid response working group, I have been active in that body. I was also chair of the symposium on this site:
and I am an author of this document:

Don't get me wrong, keeping the Asian carp out of the Great Lakes is a very, very, good idea. It is just that there are some inaccuracies that get into the media usually through well-meaning misinterpretation, and the inaccuracies that are sound most astounding (and thus, usually are wrong) are the ones that are repeated in the media. Sometimes misleading information is repeated from media sources, even by scientists. I saw the reference to the amount Asian carps can filter on the site. This is an example of how misleading information gets repeated. I will see about having that number either removed or put in context.

Henry HendersonDec 18 2009 04:29 PM

Thanks for your comments. It is good that you are engaged in the discussion and actively involved in working on the Carp issue. It is critically important that the scientific community, and USGS in particular is engaged in finding solutuons to the threat of invasive species to our great hydrological ecosystems.
The fundamental point of agreement is as you write above:
"We do have a disaster here in the central United States, and carp in the Great Lakes could turn out to be another disaster, in a place where the value of the fishery is much, much, higher."
Like many invasive species, once established in the Great Lakes, the Carp will change the quality of the Lakes and be almost impossible to eradicate. Therefor, strenuous measures must be implemented immediately to keep them out, while appropriate, perminent measures are evaluated, analyzed aganist appropriaate alternatives, and then smartly implemented.
NRDC's concern is that the current set of authorites (the Corps, the state of Illinois and the Water Reclamation District) contemplating the situation seem to be remarkably content to move very slowly, to defer to narrow special interests benefiting from the staus quo, and to feel no urgency about the unaccesptable risk presented to the broad public interest.
That is why we seek immediate emergency measures and the immediate initiation of a robust, scientifically based, legally rigorous public process that delivers a full Environmental Impact Statement, based on real science, real engineering alternatives and real economic data, and forming a real, workable plan to fix the problem. Such a plan will put us on a better economic AND environmental footing, to protect the water, public health and promote the regional economy.
The USGS is a necessary part of getting
this right---as is the National Academy of Science, and the Great Lakes community to assure that the job is underway and completed, and not left to the here-to-for lugubrious attention of the Corps, the State of Illinois and the Water Reclamation District of Greater Chicago.
These are the real facts, needs and opportunites arising from this crisis.
Henry Henderson

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