New prospect of controlling zebra mussels?

Zebra Mussels. Photo: GeraldM, Creatuve Commons, some rights reserved

Zebra Mussels. Photo: GeraldM, Creative Commons, some rights reserved

Area boaters and swimmers have been dealing with zebra mussels and their spread for the past 25 years, more or less.

The U.S. Geological Survey has a useful information page on those invasive mussels, including maps of their known distribution to date for zebra and quagga types. Researching this post I learned that zebra mussels are native to the Black, Caspian and Azov Seas. Here’s the USGS summary of the creature’s spread:

By the late 18th and early 19th centuries, zebra mussels had spread to most all major drainages of Europe because of widespread construction of canal systems. They first appeared in Great Britain in 1824 where they are now well established. Since then, zebra mussels have expanded their range into Denmark, Sweden, Finland, Ireland, Italy, and the rest of western Europe. Zebra mussels were first discovered in North America in 1988 in the Great Lakes. The first account of an established population came from Canadian waters of Lake St. Clair, a water body connecting Lake Huron and Lake Erie. By 1990, zebra mussels had been found in all the Great Lakes. The following year, zebra mussels escaped the Great Lakes basin and found their way into the Illinois and Hudson rivers. The Illinois River was the key to their introduction into the Mississippi River drainage which covers over 1.2 million square miles. By 1992, the following rivers had established populations of zebra mussels: Arkansas, Cumberland, Hudson, Illinois, Mississippi, Ohio, and Tennessee. By 1994, the following states had reported records of zebra mussels within their borders or in water bodies adjacent to their borders:Alabama, Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Utah, Vermont, West Virginia, and Wisconsin (Benson 2012). More recently, Connecticut has been added to the list of states where zebra mussels have been found.

It reads like like some inexorable march, doesn’t it? Daunting enough to think shoot, that’s that – they are here to stay. Well, maybe, maybe not. Reporting for the New York Times on Feb 24th, Robert H. Boyle details a promising development:

Now the mussels may have met their match: Daniel P. Molloy, an emeritus biologist at the New York State Museum in Albany and a self-described “Bronx boy who became fascinated by things living in water.”

Inspired by Rachel Carson’s “Silent Spring” in high school, Dr. Molloy, now 66, has long been a pioneer in the development of environmentally safe control agents to replace broad-spectrum chemical pesticides.

Leading a team at the museum’s Cambridge Field Research Laboratory in upstate New York, he discovered a bacterium, Pseudomonas fluorescens strain CL145A, that kills the mussels but appears to have little or no effect on other organisms.

The article says New York State has licensed a California-based company, Marrone Bio Innovations to produce a commercial product “Zequanox” with impressive test results thus far. (According to the manufacturer, Zequanox has been approved in California for  control of zebra and quagga mussels in pipe systems since November of last year.)

As recounted in the same Times article, Molloy has an inspiring life story. Earlier in his career he was part of an international effort that established the potential of Bacillus thuringienis israelensis, or Bti, as an environmentally benign way to control for black fly larvae.

It may be wishful thinking to expect a magic wand that produces exactly the results wanted – with no down-side or unintended side effects. But this is an interesting development, with appealing results to date.

I’m just coming to the topic as a lay person who cites articles of interest. Undoubtedly many In Box readers have first-hand experience with invasive mussels and some also have expertise on the subject of wildlife management, control efforts, etc. I’m interested in hearing  more thoughts on this issue.

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29 Comments on “New prospect of controlling zebra mussels?”

  1. knuckleheadedliberal says:

    Just FYI for those not familiar with the south eastern fringe of our congressional district, Cambridge is in southern Washington County.

    Get ready to hit the dislike button – because sometimes I just can’t help myself – Molloy is a carpetbagger from NYC living in our district.

  2. Kent Gregson says:

    This same New York Times article was reported in this week’s Glens Falls Chronicle. Cambridge is in the Chronicle’s coverage area. Knucklehead may want to get more info before he decides how to react. Who cares where the guy lives or came from. He’s not running for office or attempting to affect policy.

  3. knuckleheadedliberal says:

    New York Times!!!!! Real locals don’t read the NYT; they don’t understand what it is like to be a Northern New Yorker.

    (It was a joke Kent. You could have just hit “dislike”. Still can…)

  4. knuckleheadedliberal says:

    I did think that many people might be interested in the “local” angle though, and most of the region isn’t in the Chronicle distribution area.

  5. Michael Greer says:

    The Zebra mussel is a big time filter-feeder, and I’m wondering if it’s rapid spread was made more rapid by dirty waters.

  6. Tony Goodwin says:

    Having done black fly control with Bti in Keene, I am very interested in the work of Dr. Molloy. The promise of Bti control is that it kills only black fly larvae while leaving the rest of the other creatures that live in the streams alive and healthy. The prescribed method in Bti black fly control included a visit to the stream the day after to assess the effectiveness of the previous day’s treatment. Consistently, in my experience, all the caddis flys and other bugs one finds in the water at that time of the year were still very much alive while the black fly larvae were all white, bloated and lifeless. I have noted that it perhaps gives one some satisfaction to imagine that they died a horrible death.

    Furthermore, 30 plus years of Bti treatment has not shown any exception to the specificity of its ability to kill only black fly larvae. For the above reasons I would trust any treatment developed by Dr. Molloy to kill only the target organism.

    Michael Greer noted that Zebra mussels are filter feeders. Black fly larvae are also filter feeders and can only survive in clean water. Perhaps the only unintended consequence in this story is that the successful efforts to clean up the Great Lakes water is what has allowed them to take hold and thrive here.

  7. Walker says:

    According to Wikipedia, Bti is also effective in killing various species of mosquitoes and also fungus gnats. I wonder if there are any critters that depend on any of these three species for a substantial portion of their diet?

    As for the Zebra Mussels, the NYT piece linked above says “Zequanox killed more than 90 percent of the mussels in a test using tanks of water from Lake Carlos in Minnesota…” If the survivors aren’t destroyed by some other means, it won’t be long before a Bti immune strain arises.

    I don’t mean to knock Molloy’s work, only to suggest that its not quite time to claim “mission accomplished.”

  8. Walker says:

    And from that same NYT piece: “The tiny mussels became a dominant species in the Hudson. Not even counting their shells, their total weight exceeded that of all the fish, plankton and bacteria combined…”

    What will be the effect of all that decaying biomass? If they treat the whole river at once, it seems like it would produce a god awful mess. But if they don’t, isn’t there a chance of new mussels from untreated areas moving right in on the treated areas? Quite a set of challenges!

  9. Lucy Martin says:

    Thanks for the experience-based comments, Tony. And good points, Walker! I was wondering about that myself.

    Assuming a magic bullet could take out all zebra mussels, what kind of rot problems – or “nature abhors a vacuum” situation – might result? Interesting questions. (This playing God stuff gets really complicated!)

  10. John says:

    Zequanox is not Bti. Its a formulation of Pseudomonas fluorescens. They are both soil dwelling bacteria. Zequanox is used to treat zebra mussels in intake and discharge pipes from power plants. It is not used to treat lakes or rivers. This is a much more environmentally sound way to control the mussels in power plants. Before Dr Molloys discovery bleach was used
    As far as Blackflies building immunity to Bti, they would have to change the pH of their gut Bti has an acidic protien that acts upon the blackflies basic gut. Its not how other pesticides work.
    People should be grateful to Dr Molloy and his crew

  11. Paul says:

    I don’t think anyone is really claiming that this is “mission accomplished” any proven treatment still requires extensive field testing to see what kind of efficacy it really has. Many things that pass through clinical testing with flying colors fails on widespread use. That is all part of science.

    ” If the survivors aren’t destroyed by some other means, it won’t be long before a Bti immune strain arises.”

    I think you mean Xequanox immune strains.

    Have black flies become immune to Bti over the 30 years it has been deployed in the field?

    Immunity is always an issue that is why we come up with new alternatives. It is like an arms race. It is going on naturally as well. Plant or animal evolves a new way to fight off a pathogen and the pathogen evolves a new way to beat that and so on and so on….

  12. Walker says:

    “I think you mean Xequanox immune strains.

    Have black flies become immune to Bti over the 30 years it has been deployed in the field?”

    You’re right, Paul, I meant that they would become immune to Zequanox (not Xequanox, by the way).

    As to the black fly and Bti, that would depend in part on how effective the treatment was. And there is no way that one could treat the entire population of black flies in North America, so there will always be a large gene pool unaffected by Bti. Zebra mussels, OTOH, are in a relatively well defined geographic area of N. America, and could, conceivably give rise to a new, Zequanox-immune strain if virtually the entire population were treated.

    While immunity may be a fairly common result of biological controls, it isn’t entirely inescapable. If one were to plan a method to eradicate the ten percent that Zequanox doesn’t affect, one could indeed obliterate the zebra mussel without creating an immune strain.

  13. Two Cents says:

    Tonight’s menu, zebra mussels in white wine,garlic and butter.
    Eat local

  14. Paul says:

    Walker, I see your point. But you don’t need to treat the entire population to have some amount of immunity develop. Mutations that are selected for and lead to immunity are entirely random and they can happen in any potion of the population where the selective pressure (in this case Bti or the other stuff) is applied.

    You don’t need to treat the entire north American black fly population with Bti to get resistant bugs.

    It is interesting when we but Bt toxin (the active ingredient in Bti) into the water we drink people think it is a good idea but when we put it into corn to kill other insects they don’t like the idea? Just goes to show how annoying black flies are! The fact is Bt is safe to use for both.

  15. Walker says:

    “You don’t need to treat the entire north American black fly population with Bti to get resistant bugs.”

    Right, but if those resistant bugs are interbreeding with a large population of bugs that lack resistance, I think the gene for resistance gets lost in the gene pool? This is overstretching my knowledge of genetics, though.

    As to the GMO issue, there are many concerns about GMOs that have nothing to do with whether Bt is safe for humans to consume. See Genetically modified food controversies for an overview.

    And although you’re almost certainly right that Bt is harmless to humans, consider the history of corporate pronouncements about safety of products. Take DDT and BPA as just two examples– industry does not have a lot of credibility with the public for a lot of perfectly good reasons.

  16. Paul says:

    Walker it is not “industry” that regulates things like the use of BT. It is science that tells us it is safe. I don’t consider biased sources like those feeding information to websites.

    For GMO’s I take the word or the scientific community (just like I do when it comes to climate change). Currently the unequivocal consensus of the scientific community on GMOs is that they are safe. It doesn’t mean we should not continue to monitor their safety but they are safe based on all the exhaustive studies done to date. GMO’s in agriculture are far more tested and regulated (USDA, EPA, FDA) than many other GMO’s we use, vaccines and things like recombinant insulin as a few examples.

    GMOs are also doing a lot to reduce our impact on the environment, so they are part of solving the climate change issue. These are just my personal views based on the science, of course folks are welcome to be concerned despite the lack of any reasons at this point.

    But that is really a different topic.

    “Right, but if those resistant bugs are interbreeding with a large population of bugs that lack resistance, I think the gene for resistance gets lost in the gene pool?”

    Not necessarily. There is a good chance that an advantageous adaptation like that would be very quickly selected for not against. I was speaking with someone here that told me that his research is showing that emerald ash boring beetles that are more cold tolerant are quickly being selected for in some areas (Rats!). Like any adaptive mutation they start as a tiny fraction of the gene pool and can quickly spread and dominate the population if the conditions are right.

    If there was a chance that Bti resistance was found in the black fly population it seems likely that, given the pressure of ongoing Bti application, that it would spread very quickly.

    It sound like we are lucky and resistance is a fairly complicated genetic event in this case so it isn’t happening or at least not at a high enough frequency. It could but we will have to wait and see, same goes for this other idea.

  17. The Original Larry says:

    Paul,
    Would that be the same “scientific community” that gave us DDT, among other things? I think some healthy skepticism is in order when it comes to the “scientific community”.

  18. Paul says:

    Absolutely, healthy skepticism is important. I have no interest in following blindly. Once we think there is an issue we need to reevaluate. I am just pointing out that at this point all indications are (and the amount of data is awesome) that GMO’s in foods are safe. Being concerned when there is zero evidence of a problem despite mountains of data is not healthy skepticism. It is denial of the facts.

  19. The Original Larry says:

    If I’m not mistaken, the creator of DDT won the Nobel Prize. He fell right off the mountain of data.

  20. Walker says:

    “There is a good chance that an advantageous adaptation like that would be very quickly selected for not against.”

    Paul, it’s only going to be advantageous in the presence of Bt– no Bt, no advantage. That’s why I think it would be quickly lost in the gene pool when the vast majority of the black fly environment was Bt-free.

  21. Walker says:

    “Walker it is not “industry” that regulates things like the use of BT. It is science that tells us it is safe. I don’t consider biased sources like those feeding information to websites.”

    Well, there are almost always scientists on all sides of any particular question:

    In the 1960s, biochemist and former chemical industry spokesman Robert White-Stevens stated, “If man were to follow the teachings of Miss Carson, we would return to the Dark Ages, and the insects and diseases and vermin would once again inherit the earth.”

    If you had bothered to look at the link I provided above, you might have found a lot of evidence that the “science” is rather less unified than you suggest. For example:

    Some scientists wishing to conduct research on genetically modified plants or seeds have been unable to obtain them for study, because of restrictive end-user agreements that limit what can be done with such seeds. Cornell University’s Elson Shields, the spokesperson for one group of scientists who oppose this practice, submitted a statement to the United States Environmental Protection Agency in 2010 protesting that “as a result of restrictive access, no truly independent research can be legally conducted on many critical questions regarding the technology”. Scientific American noted that several studies that were initially approved by seed companies were later blocked from publication when they returned “unflattering” results. While arguing that seed companies’ intellectual property rights ought to be protected, Scientific American calls the practice dangerous and has called for the restrictions on research in the end-user agreements to be lifted immediately and for the Environmental Protection Agency to require, as a condition of approval, that independent researchers have unfettered access to genetically modified products for testing. In February 2009, the American Seed Trade Association agreed that they “would allow researchers greater freedom to study the effects of GM food crops.” This agreement left many scientists optimistic about the future, but there is little optimism as to whether this agreement has the ability to “alter what has been a research environment rife with obstruction and suspicion.”

    Gene modification has been extensively studied: there are more than 2,000 studies, of which 1,000 have been done by independent researchers. A 2013 review of 1,783 papers on genetically modified crops and food published between 2002 and 2012 found no plausible evidence of dangers from genetic engineering to humans or animals.

    [But] Independence in research has been studied by a 2011 analysis into conflicts of interest which found a significant correlation between author affiliation to industry and study outcome in scientific work published on health risks or nutritional assessment studies of genetically modified products.

    And like the DDT story, it’s not all necessarily about human health: “There are concerns that the genetic diversity of crops might decrease (as the development of genetically modified varieties would lead to fewer cultivars being used overall…” And “The escape of genetic modifications into neighboring crops is of concern to farmers whose crops are exported to countries that have not approved harvests from modified crops.”

    Paul, how many scientists would have told you that DDT was unsafe in 1950? Or that it would wipe out eagles and songbirds?

    I’m not saying that I think GMO crops are unsafe. I am saying that we don’t have the full story yet.

  22. Paul says:

    ” I am saying that we don’t have the full story yet.”

    Yes, and you are welcome to wait around for the data that may some day show there is something harmful about using artificially genetically modified plants.

    I find it troubling (like with climate change denial) that some feel that just because we have not yet identified some data that points to a problem (or in case of climate change data indicating that there isn’t a problem) that we should not utilize what can benefit us and the environment greatly. Walker I am not referring to you. So don’t go there.

    The use of GMOs is an important part of preventing environmental degradation and man made induced climate change. We cannot afford to wait around.

    If we wait long enough perhaps we will find scientific evidence of the existence of big foot??

    As far as I am concerned the jury is out, the trail is over. You and I just disagree. Nothing new.

    But like I said I am always open to see any evidence that contradicts what we already know. If we need to have a re-trial someday we can do that.

    On your reference above. Sure like Shield’s and others have said more access to some things would always be better. But I think what you quote here is important:

    “Gene modification has been extensively studied: there are more than 2,000 studies, of which 1,000 have been done by independent researchers. A 2013 review of 1,783 papers on genetically modified crops and food published between 2002 and 2012 found no plausible evidence of dangers from genetic engineering to humans or animals.

    [But] Independence in research has been studied by a 2011 analysis into conflicts of interest which found a significant correlation between author affiliation to industry and study outcome in scientific work published on health risks or nutritional assessment studies of genetically modified products.”

    In this particular case whether the work was done by independent or “non-independent” lab the results were all the same. If some found one thing and some found something else I would be concerned. But since the independence of the lab had no correlation with results (they were all the same) it doesn’t matter.

  23. The Original Larry says:

    I knew it was going to be about climate change, sooner or later. The really troubling thing is the blind acceptance some have for “the science” and the consequent ridicule of anyone who doesn’t agree to the same extent. Science is no more immune from mistakes, exaggeration and down-right fraud than any other discipline, no matter how high the “mountain of data” seems to be. DDT wasn’t enough? How about Thalidomide, statins or any number of dangerous antibiotics? Do we even want to think about the ramifications of the “we’re running out of oil” jeremiads of the 60s, 70s and 80s? I don’t even have the energy to go into all the outright scientific frauds perpetrated on people who were persuaded by supposed mountains of data. I think some measure of caution is always wise before jumoing in the latest bandwagon, scientific or otherwise.

  24. The Original Larry says:

    It should have been “jumping on”. My typing isn’t what it once should have been.

  25. Paul says:

    Larry, the denial that so many people have regarding climate change (like with GMOs) is something that should come up and up.

    There is a grand canyon between a “measure of caution” and the denial of the scientific facts that are staring us in the face regarding both of these issues.

    Some people are even foolish enough to lump climate change in with what you call “scientific fraud”. That is a pathetic denial of the facts – not ridicule. It is what it is. Once some reputable scientists have sufficient data showing that the phenomena doesn’t exist then we can re-evaluate like we have done in the past for other things (you gave several examples). And since so much research is being done on climate change (and the human induced components) if the facts regarding it’s non-existence were to surface we will know about it.

    “Science is no more immune from mistakes, exaggeration and down-right fraud than any other discipline, no matter how high the “mountain of data” seems to be.”

    This is not really accurate. Many “disciplines” are not subject to public and peer review like science is. The data has to be made public others need to be able to test the results, it is not taken for granted. But sure there have been some issues. That does not mean we should just forget all the other relevant lessons we learn from the scientific data.

  26. The Original Larry says:

    “Science is no more immune from mistakes, exaggeration and down-right fraud than any other discipline, no matter how high the “mountain of data” seems to be.”

    Not accurate? It most certainly is! Anyone heard from the “cold fusion” guys lately?

  27. The Original Larry says:

    By the way, calling people “foolish” and categorizing their beliefs as “pathetic” qualifies as ridicule. Oh, I know, if it’s true, then you’re entitled, right? Remember that when what goes around comes around.

  28. Lucy Martin says:

    I actually agree that science sometimes creates its own orthodoxy – even when it is mistaken. But it’s funny you should mention cold fusion, OL.

    Without taking any position on its viability, I seem to recall a small flurry of recent news stories saying cold fusion is back, so to speak.

    Here’s something from Wired UK “Cold fusion continues to progress steadily into mainstream”. Another item from CBS’s 60 Minutes called “Cold Fusion is hot again.”

    Those aren’t even the items I saw earlier, they’re just what came up in an Internet search. Of course, it could still just be talk, or posturing to lure investment. Health skepticism is…healthy!

    Or it could be this is finally making meaningful progress. Stay tuned on that one.

  29. Walker says:

    Meanwhile, the rapid discrediting of the original claims about cold fusion is an excellent example of the system of peer-reviewed science working exactly as it ought. Cold fusion made a huge splash in the popular press because it would be an incredible boon if it could be made to work. But when scientists in large numbers tried and failed to replicate the effect, it was very rapidly discredited. This is what happens when researchers make overblown claims based on insufficient data.

    There is no comparison at all between the rapidly discredited, premature claims of two researchers about cold fusion twenty years ago and the long-term, steady results of some 97% of the world’s climate scientists’ concurrence on the basic facts of global climate change.

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