Fish Fry Day: Rainbow Smelt

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Here we are again – at the end of a long work week and looking forward to all things fried on Wisconsin menus. That’s right, it’s the day of our great state’s world-famous fish fries and that means it’s “Fish Fry Day” here on the blog.

Today’s special – rainbow smelt.

Rainbow smelt (osmerus mordax) Photo: New York DEC

Rainbow smelt (osmerus mordax) Photo: New York DEC

How did these small, but voracious, fish get to Wisconsin? Well, like many invasive species, they first moved into the Great Lakes. In fact, according to the Minnesota Sea Grant, “it is generally accepted that the Great Lakes population of rainbow smelt resulted from their being stocked into Crystal Lake, Michigan, in 1912.” Why would people throw smelt into a lake, you may ask? Continue reading →

Late Spring, but Early Start for Crystal Mixing Experiment

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by Colin Smith

Year two of the Crystal Lake Mixing Project’s rainbow smelt (Osmerus mordax) eradication efforts have officially begun.  The project is testing a new method of removing cold water invasive fish from a lake inhabited by warm water tolerant native species.

Panorama of the Crystal Mixing crew getting ready to deploy the experiment for 2013. Photo: Goisa Golub

Panorama of the Crystal Mixing crew getting ready to deploy the experiment for 2013. Photo: Gosia Golub

Essentially, the experiment involves big trampoline-like air bladders that rise and fall through the water column throughout spring and summer. The hypothesis is that this mixing will warm the entire lake and prevent the cold, bottom layer of water from forming in the summer, giving cold water smelt nowhere to go. (Read more about the mechanics of the project here.)

“We wanted to get the mixing system deployed and operational as soon as remnants of the long winter’s ice melted from the lake,” says Center for Limnology research technician, Colin Smith. “The mixing system transfers heat to the lake on an incremental basis, so every day of mixing brings us closer to our goals.”

Last season the experiment exceeded expectations, warming hypolimnetic (usually the cold, bottom layer of the lake) to temperatures of 21 degrees Celsius for 25 days before autumn air temperatures drastically cooled the lake.  By comparison, when the waters aren’t being mxied, Crystal Lake’s summer hypolimnetic temperatures don’t rise above 7 degrees C.  In addition to the stellar performance of the lake mixing technology (a full order of magnitude more efficient than aeration lake mixing technology), another hypothesis gained some preliminary support.

Called the “thermal stress hypothesis,” the idea is that, basically, the lack of the cold deep waters of the lake will stress smelt so much that they couldn’t survive.

“Around the middle of August 2012 the smelt population began to behave completely differently than has previously been observed in Crystal Lake,” says CFL graduate student and long-time Crystal “crew member,” Zach Lawson. Smelt were congregating at the surface in large numbers and generally moving in unusual patterns. “By the end of September, a significant portion of that population had disappeared.  Our preliminary data suggests sixty to ninety percent of the rainbow smelt population expired and we are eager to begin sampling efforts this season to check our estimates.”

(all slideshow pictures courtesy of Gosia Golub, expect final picture, courtesy of Steve Carpenter)

As of May 14th this year, lake mixing has begun.  The hard work of the crew, including the generous contributions of volunteers Gosia Golub and Jill Marzella, enabled the group to finish assembly and deployment by the end of last weekend.  The team worked non-stop for twelve-hour days on both Saturday and Sunday in the freezing wind and falling snow.

“By the end of operations we were in a position to conduct some initial testing and, a few days later, press the start button on the mixing system,” says Smith. “We are excited to observe how the smelt population responds this year as well as how Crystal Lake’s ecosystem responds in general.” Hopefully it’ll mean a lot fewer smelt and a lot more perch and walleye. To quote Crystal crew member, Page Mieritz, “Let the mixing begin!”

If all goes according to plan, there won't be any rainbow smelt at all for Page Miertz to pull out of this gill net in Crystal Lake.

If all goes according to plan, there won’t be any rainbow smelt at all for Page Mieritz to pull out of this gill net in Crystal Lake. Photo: Adam Hinterthuer

Watch the waters warm in Crystal Lake and get project updates here. (crystallakemixing.com)

Nearshore Construction + Heavy Rain = Sediment Plume in Lake Mendota

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We interrupt this “Fish Fry Day” to bring you breaking news. Or, well, not news, but a timely example of the challenges urban water bodies like Madison’s lakes face on a daily basis.

On his way in to work this rainy morning, CFL graduate student (and “David Buoy‘s handler”), Luke WInslow, snapped a few pictures of runoff from the Memorial Union construction as it headed downhill and ended up in the choppy Lake Mendota waters, creating a sediment plume along the shoreline.

Runoff from the Memorial Union construction project enters Lake Mendota after a rainy Friday morning. Photo: Luke Winslow

Runoff from the Memorial Union construction project enters Lake Mendota after a rainy Friday morning. Photo: Luke Winslow

While not the main source of pollution in Lake Mendota Continue reading →

Lake Life Ramping Back Up, Clear Water Phase on Its Way

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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.

Spring plankton community, Lake Mendota from Center for Limnology on Vimeo.

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 Paul Hanson and Cayelan Carey take measurements on Lake Mendota as part of the Global Lake Ecological Observatory Network's "Spring Blitz" monitoring project.

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.

Road Block: Study Maps Stream Barriers in Great Lakes Basin

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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

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 →

Fish Fry Day: Jumpin’ Muskies

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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

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.

Here’s an amazing slideshow of jumping muskies in Madison from M F Davis’s Flickr stream. And a nearly viral video taken right here in Madison!

 

Video: 2 Months Breaking Ice in Under 5 Minutes

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While this isn’t news directly from the Center for Limnology, it is WAY cool and postdoc, Cayelan Carey’s, recent talk on (and love for) all things phytoplankton inspired us.

Marine scientist/science writer, Cassandra Brooks, is currently on an expedition in Antarctica’s Ross Sea, chasing phytoplankton blooms (literally) around the end of the earth. Funded by the National Science Foundation and aboard the stalwart icebreaker, the Nathaniel B. Palmer, Brooks compiled this time-lapse video of two months at sea. Enjoy.

For more on the expedition, Brooks is blogging about the experience for National Geographic. Maybe yours truly will try re-creating the experience aboard our vessel, the Limnos, during cyanobacteria season on Lake Mendota!

Our Weekend as a Walleye Nursery: Video and Pics

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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

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

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

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

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

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!

“David Buoy” Ready for Year 6 on Lake Mendota

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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

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 with the Wisconsin capitol building in the background.

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 →

Fish Fry Day: A Side of Rice

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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

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 →