A trip out sampling on Lake Mendota this morning yielded a robust catch of the zooplankton (tiny animal), Daphnia, a miniscule, yet voracious crustacean that goes to town on phytoplankton (tiny plant) populations that are blooming throughout the upper reaches of the water column.
Eventually we’ll see so many Daphnia eating so many tiny green phytoplankton, that the waters will become crystal clear. This fleeting “clear water” phase will only last until the surface waters warm and send Daphnia down below hunting for cooler waters. Then the opposite of “clear water” will occur as blue green algae (cyanobacteria) blooms that we know all too well on Mendota take over. Unfortunately, these are just as unpalatable to any grazers in the lake as they are to those of us watching the green scums from the shore…
The sampling was part of the Global Lake Ecological Observatory Network’s “Spring Blitz,” an unprecedented limnological effort to simultaneously monitor spring transitions on lakes around the globe. More to come on that next week. Stay tuned!
The CFL’s Cayelan Carey and Paul Hanson take measurements on Lake Mendota as part of the Global Lake Ecological Observatory Network’s “Spring Blitz” monitoring project.
Over the last several years, state agencies and environmental non-profit organizations have targeted dam removal as a way to quickly improve the health of aquatic ecosystems. Dams keep migratory fish from swimming upriver to spawn, block nutrients from flowing downstream, and change the entire hydrology of a watershed. From an ecosystem perspective, taking down a dam and returning a river to a more natural flow seems like a no-brainer.
Dam removal projects are costly and time-consuming. They may also be only part of the solution. Photo: Michigan Department of Natural Resources
But a new study says that most dam removal efforts are missing an important part of the picture – you can’t talk about river restoration without also talking about roads.
In the study, published in the May issue of the journal Frontiers in Ecology and the Environment, a team of researchers mapped out every obstacle, from large hydroelectric dams to tiny road culverts, in the entire Great Lakes drainage basin. What these maps show is that, while there are more than 7,000 dams on the rivers, creeks and streams flowing into the Great Lakes, there are 38 times that number of road crossings. Or 268,818, to be precise. Continue reading →
Well, we’ve once again made it to the day when fried fish dominates Wisconsin menus, which means it’s Fish Fry Day on the blog!
Every spring, fish all over the world feel the warming waters and head upstream to spawn. And every spring, millions of fish run into one insurmountable obstacle to their inner drive – dams.
A muskellunge tries to clear the Wingra Creek Dam in Madison, WI. Photo: Brenda Pracheil
Here in Madison, the Wingra Creek Dam is a good place to spot big muskies trying to leap their way into Lake Wingra. They’re not exactly champion jumpers of the fish world, but it’s still a cool display. Luckily for them (and folks who like to fish for them) other muskies have better luck in more accessible tributaries. This year’s run has wound down, but we’ve got some good shots to tide you over until next year.
Last Friday, Wisconsin Department of Natural Resources fisheries biologist, Kurt Welke, poured more than a quarter of a million fish into our boat slip here at Hasler Lab.
Kurt Welke, WDNR fisheries biologist, dips a jar of water (and walleye) out of the Hasler Lab boat slip. Photo: Denise Karns
Welke was headed to Lake Mendota with precious cargo – 300,000 young walleye fry. Part of the WDNR’s annual fish stocking in the Madison lakes, the little fish were to be released into the lake in hopes that a number of them would survive to a nice, fat, happy adulthood of being both an apex predator and a tasty dinner for area fishermen.
These walleye, and roughly 299,000 others spent a calm weekend in the Hasler Lab boat slip. Photo: Denise Karns
The problem was, last Friday was no day to be pouring helpless fry into the lake. A northern wind had waves pounding the shoreline, making it impossible for them to get to the near-shore cobble, the area the small fish would first use to hide out from predators.
The same waves pounding the boat slip door, were making the walleye’s preferred habitat unsuitable for stocking last Friday. Photo: Denise Karns
Welke had an idea. The same rough water that made the lake a dicey proposition for the fish meant that no one here at the lake was taking our boats out either. And that meant that, safe behind the wave-pounded boat slip door, there was a small refuge of calm water. Welke decided to let the fish get acclimated to Lake Mendota for the weekend by hanging out in our boat slip.
On Monday, LTER research specialist, Ted Bier, and CFL post-doc, Jereme Gaeta, were on hand with your trusty blog author for the release.
CFL postdoc, Jereme Gaeta, watches as Ted Bier raises the boat slip door and walleye fry begin streaming out. Photo: Adam Hinterthuer
It was a flat-water, picture-perfect day and, the moment the boat slip door cleared the water, 300,000 little walleye knew exactly what to do and streamed out into the lake.
Perhaps several years from now, these fisherman will pull one of “our” walleye out of the waters of Lake Mendota. Photo: Adam Hinterthuer
We were happy we could help them weather the storm and wish them smooth sailing and rapid growth in the future!
Early season boaters on Lake Mendota may have noticed a familiar sight out on the water this spring – a bright yellow beacon, bobbing right above the lake’s deepest point.
David Buoy ready to record measurements on Lake Mendota for the 2013 season. Photo: Luke Winslow
Meet “David Buoy,” the tireless floating scientific instrument that has plumbed the depths of our fair lake for five years. Luke Winslow, a graduate student in the Hanson Lab at the Center for Limnology, has been with the buoy since the beginning. Starting the project as an undergrad, Luke has helped fine-tune the instruments collecting data, dealt with random acts of vandalism, and monitored conditions in Mendota. The data collected by the buoy (some available online in real-time) will help researchers here at the CFL better understand what drives the health of Lake Mendota and how human activities affect its waters.
For example, using data in part collected by the buoy on water temperature and plankton communities, scientists at the CFL can now predict in the spring what harmful algal blooms are likely to be like in the summer.
Luke Winslow works to get “David Buoy” installed for a field season. Photo: Ted Bier
Winslow recently worked with a team of divers and researchers to get David Buoy out onto the lake for 2013. He sent in this write up below: Continue reading →
We know, we know, this is the day reserved for a cute little picture and “did you know” factoid about some of our favorite fish. It’s a tradition (since April) to celebrate Wisconsin’s day when fried fish is on the menu and it’s often all-you-can-eat. But, you know what? Sometimes you need to take it easy on the ol’ arteries. And that’s why this week’s installment of Fish Fry Day is giving you a big heaping side of wild rice.
A couple of canoes glide through beds of wild rice. Photo: University of Minnesota, National Center for Earth-Surface Dynamics
Yep, zizania palustris, or northern wild rice is native to the Great Lakes region and people have been eating it since prehistoric times. Long before we’d developed the appropriate technology to deep fry our fish fillets, people were paddling through Great Lakes wetlands, bending these long green stalks over their canoes and knocking ripe grains into their boats with wooden flails.
Wild rice (or manomin which means “good berry”) was a staple food for Ojibway, Continue reading →
The WDNR Fisheries and Aquatic Sciences Research team (Kelly Wagner, Michelle Nault, Ali Mikulyuk, and Martha Barton) with their awards. Photo: Ali Miklulyuk
Earlier this month, CFL graduate student and Wisconsin DNR research scientist, Alison (Ali) Mikulyuk received the 2013 Wisconsin Lake Stewardship Award along with her colleagues Martha Barton, Michelle Nault, & Kelly Wagner for their work with the WDNR‘s Fisheries and Aquatic Sciences Research department. (In Wisconsin Lake circles, they’re affectionately known as the “Plant Divas.”)
Ali at work in a parsnip field. Photo courtesy: Ali Mikulyuk
We prefer the term “award winners” since it’s a known fact that we love to brag on our students at the CFL and think they’re pretty much going to save freshwater as we know it. Ali, however asked if we could instead point the spotlight on the long and storied history of other women in limnology.
We were more than happy to oblige – especially since there is such an awesome roster of amazing scientists to choose from. Ali wrote up the following three blurbs. We know it’s slanted toward dead American scientists and not at all comprehensive, but it’s a cool list nonetheless. We are more than happy to hear suggestions of other (preferably even living!) notable women limnologists, ecologists, hydrologists, etc. in the comments section! Continue reading →
Wisconsin, of course, is where it all began, thanks to former U.S. senator Gaylord Nelson’s vision. As we here at the blog mulled over an appropriate topic for an Earth Day post, we kept seeing local media coverage about Madison’s lakes. And that had us returning to one thought – April rains bring July pains.
Satellite view of phosphorous-driven algal blooms. Phosphorus carried into Lake Mendota via the Yahara River fertilizes algal growth. Photo: UW SSEC and WisconsinView
While the entire Midwest has been waiting for spring to finally fight off winter (sorry, Minnesotans) and get some of those May flowers out of the ground, our daily deluges also have a longer-lasting impact. We asked Center for Limnology director, Steve Carpenter to comment on this soggy spring and here was his reply: Continue reading →
It’s that time of week again. Time for fried fishes of all sorts to pop up on Wisconsin menus and time for us here at the blog to feature a new fish for “Fish Fry Day.” Today’s species comes courtesy of Center for Limnology post doc, Brenda Pracheil – the longnose gar.
Longnose gar. Photo courtesy: New York DNR
According to Brenda, many folks view the longnose gar as a “trash fish” that preys on more desirable sport fish species. “But,” she counters, “longnose are native predators and among the most primitive of the fishes in the Mississippi Basin.” Continue reading →
Aaron Koning collects water samples on Thailand’s Yuam River
While a lot of what we do at the Center for Limnology is all about Wisconsin waters, we’ve got some world-class research going on all over the world, from places like Tanzania and Thailland. Aaron Koning, a grad student in Pete McIntyre’s lab, is working on understanding the fish communities in both the Chao Phraya and the Mekong rivers in Thailand. Both of these major rivers support important, but threatened, fisheries.
Aaron recently wrote in with this dispatch from the banks of the Yom River, a tributary of the Chao Phraya:
Following Pete [McIntyre]’s return to the U.S., I set off to repeat the fish community collection and nutrient limitation experiments that we had conducted previously in the Salween River basin. While I had intended on conducting this second round of work on a Mekong River tributary, the site at which I had access turned out to be less than ideal.
Already set back a week due to illness, I decided to return to a community that I knew well in central Thailand on a tributary of the Chao Phraya river, rather than seeking out a new site and trying to rush introductions to a new community of people. Continue reading →