October 2014 Newsletter

Letter from the Director

Dear Friends—

Currently, MAISRC supports the research of five lead investigators and their teams. They are working to answer questions we believe are crucial for devising better ways to slow and reverse the spread of species such as Asian Carp, watermilfoil, and zebra mussels. Some of the specific questions include: Is there a virus that could act as biological control of Asian carp? What are the key pathways of zebra mussel spread in Minnesota? To answer any of these "big" AIS questions, a research team must conduct many specific studies, often spanning laboratory assays, controlled experiments, and field surveys.  MAISRC must choose its research questions strategically because each is a major commitment of resources: people, facilities and equipment, time, and money.  

How do we select research questions?  First, we need to identify which species pose the biggest risks to Minnesota's lakes, rivers, and wetlands.  Species that are rapidly spreading, like zebra mussels, and others, like milfoil, that defy current control options are obvious choices. But there many more –over 50 species – that potentially could be problems in the not-too-distant future. It can take a decade or more to devise new solutions, so we need to assess which ones deserve pre-emptive attention. Top candidates are species that are problematic in nearby states. Second, for each priority species, we determine what research has already been done by other scientists, and based on their published research findings, identify the key uncertainties posing barriers to better management. Input from AIS managers is also important, to learn what they are experiencing and observing in the field. What do they need to know to have more success beating aquatic invasive species?

At this point, the list of potential research questions is huge—greatly exceeding what we can attempt, even if MAISRC had many more scientists. We need to prioritize based on the likelihood that answering the question is feasible, whether we can attract scientist(s) with the necessary expertise, and how important the question is relative to the resources needed to answer it. Once we have a short list of questions, proposals are developed and funding is sought. We add new topics to our current research portfolio as new funding becomes available.

The process I've just described is what we call a Research Needs Assessment. Because the realm of aquatic invasive species is rapidly changing, MAISRC should assess research needs much more frequently than most other kinds of scientific research centers—in fact we're assuming we'll do this annually. Our first comprehensive research needs assessment is happening this fall. We've established an assessment team of MAISRC scientists, agency biologists and AIS managers from Minnesota, and national experts who will recommend new research questions to add to our current slate of work. This assessment will only be as good as our initial list of possible questions, so we hope to tap the expertise of everyone in Minnesota who has been working to stem the advance of AIS. You can contribute your research ideas online (details are provided in this newsletter) until November 1 – it will only take a few minutes and will help make the assessment more robust.

Thanks your continued support of MAISRC and all of your efforts to preserve the quality of Minnesota's lakes, rivers and wetlands for future generations.

Dr. Susan Galatowitsch
Director, Minnesota Aquatic Invasive Species Research Center

Two Invasive Plant Projects Launched

Curlyleaf pondweed and Eurasian watermilfoil are major pests in Minnesota, occurring in over 750 and 280 water bodies respectively, disrupting recreation, and suppressing native species.  While some methods to control these plants are already available, cost- effective and environmentally-sound options are needed. That's where Dr. Ray Newman's work comes into play. Starting this fall, Dr. Newman and his team are investigating biological control of Eurasian watermilfoil by a small native insect called the milfoil weevil. This weevil has been shown to reduce Eurasian watermilfoil in some lakes; however, something appears to be limiting its effectiveness in others. Dr. Newman suspects that bluegills, which feed on the weevils, are the culprits. To test his hypothesis, Dr. Newman will use vinyl experimental enclosures (similar to those pictured) in test lakes to determine if altering the sunfish population densities and size structures can create a quality fishery while also enhancing the milfoil weevil's ability to safely and affordably control Eurasian watermilfoil.

Dr. Newman will also be analyzing data collected over the last 10-15 years by the Minnesota DNR, the University, watershed districts, and others on the response of curlyleaf pondweed—and native plants—to management. Gathering and analyzing this data will answer several questions: 1) how many subsequent herbicide treatments are needed for effective control 2) what time of year and/or how broadly applied should the treatments be to produce the best results and 3) how do native plants respond to curly leaf herbicide treatments? Dr. Newman hopes to have results to share by December, 2016. 

Judas Fish technique closer to use with Asian carp

Sixteen Silver and Bighead carp have been caught in Minnesota since 1996, with the most recent being a Bighead caught September 16 at the mouth of the St. Croix River. While we have no way of knowing for sure, we suspect that these catches are of outlier individuals that are not successfully reproducing. But how can we confirm this is the case and also possibly remove these fish given that traditional methods of netting and electrofishing Asian carp are next to impossible?

Dr. Ratna Ghosal, a post-doctoral researcher working with Professor Peter Sorensen, has spent the last two years developing a technique that could do just this. Dr. Ghosal is building on the Sorensen Lab's success controlling common carp using the Judas fish technique— a technique in which a few radiotracked individuals are followed as they locate (and thus betray) other members of their group. Sorensen's Lab, with the help of commercial fishermen, has been able to net and remove up to 80% of the biomass of common carp in lakes in a single day.

Dr. Ghosal is determining if the Judas fish technique might be used with Asian carp in rivers as well. This may sound simple, but it is not. First, Dr. Ghosal needed to determine if Asian carp aggregate like their common carp cousins by conducting several tests on their shoaling behavior. She found out that they do.

Next, she needed to determine if she could enhance the tendency of carp to aggregate by making individuals sexually receptive to attract others.  She discovered this was possible using goldfish (pictured) as a model and implanting them with hormones that both drive sexual behavior and cause them to release sex pheromones.  Experiments are now starting to extend this work to Asian carp.

Dr. Ghosal has also been working with a veterinarian to determine if Asian carp can be sterilized so that researchers may safely release a radio tracked individual into the wild without the concern that it might reproduce.  Initial indications are positive, though the sterilized fish are still being monitored.

What's next for this technique? More trials need to be conducted using hormones on Asian carp, which she expects to complete by next summer. Dr. Ghosal hopes she will then be able to put the technique to the test in large experimental ponds, using sterile Asian carps that have been implanted with radio tags.

MAISRC wants to hear your research ideas!

MAISRC is conducting its first comprehensive research needs assessment and wants your input. What research do you think needs to be done to help stem the advance of AIS in our waters? Please let us know your thoughts via this online survey. All ideas submitted by November 1 will be considered in the needs assessment. Results from the needs assessment will guide development of future MAISRC research projects. 

Save the date! MAISRC Showcase: November 19, 2014

The Center will be hosting this conference and inside-look at the MAISRC on the University of Minnesota St. Paul campus on November 19, 2014. Geared toward county government, watershed district and lakeshore association decision-makers, the Showcase will provide an opportunity to interact with faculty and researchers as they share the latest about their work. Space is limited and registration will be required. Watch your inbox in the next two weeks for a full announcement and registration information.

New peer-reviewed paper provides insights into Asian carp feeding success and offers opportunities for control

MAISRC researchers, along with their colleagues at Louisiana State University and University of Colorado, have published the results of a study that may help us figure out how to control Asian carps. Dr. Peter Sorensen led a team, including post-doctoral researcher Ratna Ghosal and graduate student Aaron Claus, that discovered the key role that a unique organ plays in the feeding behavior of these fish. They found that the epibranchial organ, a tubular structure located at the back of the mouth, is covered in taste buds (pictured) and other chemosensory receptor cells that help Asian carps identify and accumulate tiny food particles from the plethora of debris ingested while they feed.  The carps' ability to consume vast quantities of these tiny plankton particles makes them among the fastest growing fish in the Mississippi. It has also led to the depletion of these small organisms at the base of the food chain, which is why these carps pose such a threat to our native fisheries. Researchers believe that the unique food sorting ability of Asian carps may be a vulnerability that future control methods can exploit—for example, this system can now be targeted with toxins or used to develop feeding attractants. The paper has been published ahead of print in the Journal of Experimental Biology.

The Research Center is hiring

The MAISRC is looking for a part-time laboratory assistant and full-time post- doctoral researcher to help with zebra mussel research. Please click here for more information and to apply.

Giving

The Minnesota Aquatic Invasive Species Research Center's establishment and initial research has been possible with significant funding through the Legislature from the State's Clean Water Fund and the Environment and Natural Resources Trust Fund, as recommended by the Legislative Citizen Commission on Minnesota Resources ("LCCMR").   MAISRC needs to leverage these funds in order to find solutions to Minnesota's AIS problems:  support from private donors is essential!

Scientific conferences can be the intellectual stimulus that feeds researchers. This is where the lastest research results are shared, ideas generated, and concepts tested with peers.  Dr. Eichmiller recently attended the 2014 Annual Meeting of the American Fisheries Society, held in Quebec City, Canada, to present a talk titled "The relationship between the spatial distribution of common carp and their environmental DNA in a small lake." Because our state grant funds cannot be used out of the country, Dr. Eichmiller was able to attend the conference with the help of a generous donor. Freshly inspired, Dr. Eichmiller will now be able to apply new ideas to her work detecting AIS in Minnesota with eDNA. 

Private donations can make a difference! If you or your organization has an interest in helping to advance the Center's efforts to find solutions to AIS problems, please contact Becca Nash, Associate Director, at nash0029@umn.edu or 612.624.4782.

Thank you to all our supporters and partners for helping to make the Center's work possible!  

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