February 2017 newsletter
Letter from the Director
Despite most of our research areas being covered in ice, MAISRC researchers didn’t slow down this winter. We have been analyzing data, working in the lab, writing papers and grant proposals, and planning for the field season to come. I remain optimistic that the research progress we are making has, and will continue to, yield actionable results. I’m pleased to highlight a few recent research findings:
- A common algaecide treatment for starry stonewort is not killing its bulbils, the plant’s reproductive structures. This knowledge will allow AIS managers to create better treatment plans and save money, and will inform future research to better target the bulbils.
- Of all the potential adverse effects from a bigheaded carp invasion, the greatest would be on game fish, non-game fish, ecosystem resilience and species diversity, and recreational hazards from jumping fish. These impacts vary in severity by watershed. Identifying these top impacts helps guide management decisions that promise to do more good than harm.
- Eurasian watermilfoil harbors a distinct microbial community compared to surrounding sediment and water. Some of these microbes have potential to be harnessed for use as a biocontrol.
- The key to the Lake Mille Lacs walleye crisis may be buried in the bottom of the lake. Researchers are now extracting frozen sediment cores and examining them for changes to the food web caused by the invasive spiny waterflea.
More research is still to come: last fall we completed our second Research Needs Assessment process (thanks to the hundreds of you who submitted ideas!) and we are now reviewing numerous research proposals. We hope to fund four or five new projects that will launch this summer. More details coming soon!
The early season thaw has MAISRC researchers excited and ready to get back in the field. There is a lot of work planned for this upcoming field season and there are opportunities for you to get involved – including through our new citizen science program, AIS Detectors, which will open for registration later this week. We will be sure to keep sending updates through the newsletter and social media, so stay tuned!
Time to get back to the lab . . .
March 15 workshop to discuss Minnesota Bigheaded carps risk assessment findings, management next steps
MAISRC researchers have completed a multifaceted, deliberative risk assessment for bigheaded (both silver and bighead) carps in Minnesota waters, the findings from which will be unveiled and discussed at an upcoming workshop.
The risk assessment included analysis by dozens of leaders in the field, including invasive carp researchers and managers from states where bigheaded carp are already established. The risk assessment focused on four watersheds – Minnesota River-Mankato, Nemadji River, Sand Hill River, and the Lower St. Croix River – and characterized the likelihood that bigheaded carps would establish there if introduced. The risk assessment also characterized the likely resulting abundance of carps in each watershed and the severity of potential adverse effects. Of all the potential adverse impacts from an invasion, the risk assessment concluded that the greatest threats are to gamefish, non-game fish, species diversity, and recreation.
“Conducting a risk assessment like this is important because people can sometimes get caught up either feeling apathetic or fearful when it comes to a complex problem like invasive species,” said researcher Adam Kokotovich. “We need to take a step back and really evaluate potential impacts in order to inform reasoned decision-making.”
The workshop provides an opportunity to hear the full findings of the risk assessment from the project’s lead researchers, and, equally important, an opportunity to discuss the implications of the findings with a broad group of stakeholders, decision-makers, researchers, resource managers and interested members of the public. Registration is free, but space is limited and RSVP is required. For more information about research on bigheaded carps at MAISRC, please visit our website.
New research shows algaecide treatments knocked back starry stonewort but failed to kill bulbils
New research findings from MAISRC show that algaecide treatments that targeted starry stonewort reduced its biomass, but failed to kill — and may have even increased the abundance of — bulbils, the alga’s primary means of reproduction.
Treatments for starry stonewort were piloted by the Koronis Lake Association last summer on Lake Koronis, the first lake in Minnesota where starry stonewort was found. MAISRC researchers partnered with the association to evaluate the effectiveness of these treatments. Different areas of the lake were subjected to mechanical harvesting only, algaecide only, or harvesting plus algaecide. Additionally, untreated reference areas were monitored to provide a baseline for comparison. The algaecide treatments included granular copper-based formulations which are specifically intended to kill bulbils.
By sampling in the lake before and after these treatments and conducting further experiments in the lab, researchers found that bulbils treated with the granular algaecide were just as viable (and therefore able to sprout and reinvade) as bulbils from untreated areas. Not only that, areas only treated with algaecide actually showed a large spike in bulbil density, which the reference and mechanically harvested areas that were not treated with algaecide did not have.
The overall biomass of the plant – which can form dense mats on the surface of the water that are hard to swim and boat through – did decrease following these treatments. However, since bulbils remained viable and abundant, the relief may only be temporary.
“Although the treatment results were somewhat disappointing, there is a lot we can learn from this,” said lead researcher Dr. Dan Larkin. “For starters, it’s good for lake users that the overall biomass decreased following treatment. We also now know that this particular algaecide regimen was not effective at killing bulbils. Going forward, we’ll be conducting lab trials on different herbicides to better target the bulbils.”
This project is part of a broader effort to evaluate treatment effectiveness in starry stonewort-invaded lakes throughout Minnesota, and research findings will be shared with herbicide producers, applicators, and lake associations. Learn more about starry stonewort and MAISRC’s research on our website.
What sediment cores can tell us about Lake Mille Lacs, walleye, and spiny waterflea
Science doesn’t stop in the winter! This month, MAISRC researchers began work to get to the bottom of how spiny waterflea are impacting Lake Mille Lacs – the lake bottom, that is. The team, led by Donn Branstrator, extracted more than 200 years’ worth of sediment from frozen Lake Mille Lacs and will analyze several decades’ worth in order to learn more about the role that spiny waterfleas have had in disrupting the food web and contributing to the walleye crisis.
To learn more, watch KSTP’s recent coverage of this work, including a video of the research in action!
Once back at the lab, researchers will cut the sediment cores into thin strips which they can look at under a microscope to tell when spiny waterfleas arrived and what the food web looked like before and after. Stay tuned for findings from this research, and learn more about spiny waterfleas here.
First hurdle cleared in search for microbial biocontrol agents against AIS
MAISRC researchers have discovered that some aquatic invasive species, specifically Eurasian watermilfoil and zebra mussels, harbor a distinct set of microorganisms when compared to their surrounding sediment and water.
This research, which was conducted at dozens of lakes throughout the state, shows that the microbial community is different enough that biocontrol using microorganisms may be an option.
“These results are promising enough that we feel it’s important to advance to the next phase of the search for biocontrol candidates,” said researcher Prince Mathai. “This will include lab trials on native species as well to limit non-target impacts. Finding a microorganism that is harmful to Eurasian watermilfoil or zebra mussels could be a game-changer for controlling these nuisance species.”
Through this first phase of research, scientists also discovered that Eurasian watermilfoil is harboring an increased abundance of fecal indicator bacteria such as E. coli and Enterococcus. Elevated levels of these bacteria in beaches or other recreational waters can have serious public health implications.
All plants and animals are covered in microorganisms; some have evolved to live in close association with aquatic organisms. These relationships may be commensal, symbiotic, or pathogenic. MAISRC researchers believe some of the pathogenic relationships could hold a key for biocontrol.
The samples of zebra mussels, Eurasian watermilfoil and their accompanying water and sediment are now being processed for physicochemical and microbiological analysis in the lab. In addition to providing valuable information on potential biocontrols, this study may also allow us to develop molecular marker methods to ascertain the presence/absence of these AIS and quantify their abundance in lakes.
MAISRC welcomes two researchers
MAISRC is pleased to welcome two new researchers to our team: Meg Thompson and Dr. Huijie Qiao. Meg is a University of St. Thomas graduate currently assisting MAISRC on research projects including Heterosporis, fish health, and ecological niche modeling.
Dr. Huijie Qiao is a visiting researcher from the Chinese Academy of Sciences in Beijing. An expert in ecological niche modeling, Dr. Qiao is joining MAISRC for approximately six months to work on modeling the spread of aquatic invasive species including zebra mussels, Heterosporis, and Eurasian watermilfoil. Welcome, both!
AIS Detectors registration opening March 1
Registration is opening March 1 for AIS Detectors, MAISRC’s new volunteer network and science-based training program launched in partnership with University of Minnesota Extension. After being certified as an AIS Detector, you’ll serve a critical role by helping the DNR respond to reports of possible AIS, weeding out false positives, being on the lookout for new infestations, and providing outreach to your community. Click here to learn more about joining this network of citizen scientists!
Save the date for the 2017 Showcase
Save the date for the 2017 Minnesota Aquatic Invasive Species Research and Management Showcase: Wednesday, September 13! This event will help you gain valuable knowledge and insight to enhance your understanding of AIS issues and the research MAISRC is conducting. You will have opportunities for hands-on activities, lab tours, lunch with researchers, and more! Stay tuned for more details.
MAISRC in the news
- Scientists look to the past to figure out the walleye collapse on Lake Mille Lacs (KSTP)
- Core samples form Mille Lacs Lake may explain walleye woes (Brainerd Dispatch)
- Invasive aquatic plant, starry stonewort, creeps across Great Lakes region (Rochester Post-Bulletin)
- Taking genetics to the lake: New study shows that fight against invasive plant is more complicated thanks to hybrids (Star Tribune)
- Battle against aquatic invasive species on Lake Minnetonka continues (Sun Sailor)
Let your legislator know you support funding for AIS research
We know that you care deeply about Minnesota's waters and protecting them from aquatic invasive species. Now is the perfect opportunity for you to let your voice be heard. Our friends at Conservation Minnesota have made it easy for you to weigh in with your thoughts about funding for AIS research in Minnesota. Click here to quickly and easily contact your legislators to ensure they know that AIS funding is important to you.
Long-term funding will help us address the numerous threats posed by AIS, and additional research will help find science-based solutions. It will only take a minute to share your thoughts with your legislators -- thank you!