Team of Scientists Hopes to Reveal Fuller Picture on Invasive Species

Today wraps up National Invasive Species Awareness Week, which was marked primarily by a series of awareness-building events and seminars in Washington D.C. It also coincided with the return of CFL grad student, Alex Latzka, from a trip to Germany where he was working with a team of scientists on a new invasive species project. 

When rusty crayfish (center) get too abundant, a lake bottom can go from lush (left), to desolate (right). But is that state the "new normal" or just a blip in the life history of the system?

When rusty crayfish (center) get too abundant, a lake bottom can go from lush (left), to desolate (right). But is that state the “new normal” or just a blip in the life history of the system?

by Alex Latzka

Alex Latzka shows off an especially large virilis (or native) crayfish.

Alex Latzka shows off an especially large virilis (or native) crayfish. Photo: Ali Branscombe

Invasive species are a huge problem for many ecosystems, including our lakes, and they’re continuing to invade new and sometimes unexpected places. One thing scientists are really missing when we study invasions is a big-picture, long-term perspective. This gap is not unique to the study of invasions – not surprisingly, most studies in any scientific field last about as long as it takes to get a PhD.

But, when it comes to invasions, this gap may be critical. What if the first five years of an invasion are remarkably different from what comes after? We often hear stories that this may be the case. “There used to be way more rusty crayfish in our lake when I was growing up,” or “I never used to see this many snails,” are anecdotes I’ve heard when discussing invasives with people who have lived on a lake for many years. And research supports some of these claims – there are scientific papers documenting similar patterns at single sites for single species.

This map of Wisconsin shows known lakes with rusty crayfish invasions. Image: Alex Latzka

This map of Wisconsin shows known lakes with rusty crayfish invasions. Image: Alex Latzka

Even though an invasive species may be very abundant and have nasty impacts now, it may not be so successful in the future. And, even if another invasive species is at low levels and not causing problems now, that may soon change. For managers of invasive species, these patterns – or what we like to call dynamics – are crucially important. If we know that it’s likely an invasive species population is going to crash down to non-harmful levels, maybe we shouldn’t invest a lot of money and effort to control it. Continue reading

“When” – Not Just “Where” – Key Question for Species Abundance

Cayelan Carey pulls a sample of plankton out of Lake Mendota. Photo: A. Hinterthuer

Cayelan Carey pulls a sample of plankton out of Lake Mendota. Photo: A. Hinterthuer

When it comes to studies of species abundance, scientists have spent a lot of time looking into where, exactly, particular plants or animals thrive or survive in a particular ecosystem. But, harnessing the relatively recent rise of long-term datasets, a new study published online in the journal PLOS ONE found that, for some species, it matters much more “when” you look.

The study was conducted by Cayelan Carey and Gretchen Hansen (both former post doctoral researchers at the Center for Limnology). Hansen is now a fisheries research scientist at the Wisconsin Department of Natural Resources. Carey is an assistant professor of biological sciences at Virginia Tech University.

We asked Carey a few questions about the study and what it was like exploring fish and phytoplankton on the – ahem – space/time continuum.

What was the central question that led to this study?

Carey: If you think back to what ecology is, it’s the study of the distributions of organisms and their interactions with the environment. So a big question is why are some species rare and others common. People have tried to answer this by, for example, going out into a forest and surveying many many plots at one time and then writing about what they found.

What we’re working on now, thanks to long-term datasets like the Long-Term Ecological Research program, is looking at what species are present at those locations over time.

We wanted to see if the spatial patterns hold if you’re looking over time. So rather than the space question of “why are some species found at every single site and others are rare,” we asked “why are some species always present and others rare?” Continue reading

Limnology in the Lab: Guppies Eating Swordfish, Bluegill Eating Shrimp

Down in the basement of the Water Sciences and Engineering Lab, right next door to us here at the Center for Limnology,  sits an aquatic ecosystem with one crazy food web.

Chelsea Blanke stands next to her experimental "habitat" of guppies, zebrafish, bluegill and minnows.  Photo: A. Hinterthuer

Chelsey Blanke stands next to her experimental “habitat” of guppies, zebrafish, bluegill and minnows. Photo: A. Hinterthuer

In the experimental habitat, four different species of fishes – zebrafish, guppies, bluegill and fathead minnows – are feasting on a scientifically measured diet of dried flakes of swordfish, walleye, perch and shrimp.

And those fish flakes, says Chelsey Blanke, a CFL graduate student working with professor Jake Vander Zanden, weren’t exactly something she could pick up from the pet store.

Food fit for a king. Or a guppy - jars of powdered swordfish, walleye, perch and shrimp.

Food fit for a king. Or a guppy – jars of powdered swordfish, walleye, perch and shrimp.

“I bought everything from the grocery store,” she says, “and did almost all of it in my kitchen. We had to peel one hundred pounds of shrimp, grind it up in my food processor and bake it in a sort of cookie,” she recalls. “It was kind of some strange cooking, you know?” Continue reading

Unexpected Find Under the Ice for Lake Mendota Researchers

Last Wednesday, a couple of researchers ventured out onto frozen Lake Mendota to drill through the ice and take their yearly winter samples for the Long-Term Ecological Research (LTER) project.

A surprise awaited them as they broke through the ice.

LTER researcher, Kirsten Rhunde, takes samples through the ice on Lake Mendota. Photo: Ted Bier

LTER researcher, Kirsten Rhunde, takes samples through the ice on Lake Mendota. Photo: Ted Bier

Instead of the usual cold-weather conditions of clear water with not much growing in it, they found the brown-colored soup of a plankton bloom.

Unexpected "soupy" water awaited researchers after they drilled through the ice. Photo: Ted Bier

Unexpected “soupy” water awaited researchers after they drilled through the ice. Photo: Ted Bier

By the time the Secchi disk reached three meters, says Ted Bier, a research specialist with the LTER, it was disappearing from sight.

Most winters, the clear water lets Bier track the disk’s descent through the water column for six meters or more. This year, however, the water was clouded by a giant bloom of diatoms, a common kind of unicellular algae. Continue reading

Fish Fry Day: Shad, Like Ships, Use Locks to Get Upstream

Happy Fish Fry Day, when, like any good Wisconsin restaurant, we put fish on the menu. Today’s post is shared with permission from The Nature Conservancy‘s “Cool Green Science” blog. Thanks, TNC! 

An Alabama shad. Photo: © Steve Herrington

New Research Makes A Strong Case for Fish Passage

By Justine E. Hausheer, science writer at the Nature Conservancy

How do you figure out where a fish was born? You shoot a laser beam at its ear bone.

It may sound like a riddle, but this technique is helping Nature Conservancy scientists protect the Alabama shad, which once swarmed up Gulf-coast rivers as far north as Iowa by the millions to spawn. But shad populations plummeted in the last century, as dams blocked their path upriver.

As covered previously on Cool Green Science, Steve Herrington, the director of freshwater conservation for The Nature Conservancy’s Missouri program, devised an ingenious way to help shad in Florida’s Apalachicola River make it beyond the Jim Woodruff Dam.

Using a PVC pipe and a pump to create the sound of running water, Herrington and his partners at the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, the National Oceanic and Atmospheric Administration, the Florida Fish and Wildlife Conservation Commission, and the Georgia Department of Natural Resources were able to coax the shad into the lock used to transport boats over the dam.

Called “conservation locking,” this technique successfully transported fish over the dam to spawn upriver, and the shad population increased by more than four fold, to an estimated 120,000 fish as of 2012. A recovering shad population is good news for the region’s sport fisheries, too, as young shad are likely an important source of prey for largemouth bass.

Keep reading at the Nature Conservancy’s “Cool Green Science” blog –> 

Field Samples: Restoring the Flow for Great Lakes’ Migratory Fishes

Field Samples is a weekly Q&A asking researchers what they’ve been up to and what they’ve learned. Today, post doctoral researcher, Allison Moody, talks dams, road culverts and getting migratory fish moving again.

Who are you, where are you from, and how did you get here?
Before turning her focus to fish, Allison Moody worked on birds.

Before turning her focus to fish, Allison Moody worked on birds. Seen here holding a scrub jay.

My name is Allison Moody and I’m a landscape ecologist who specializes in conservation biology. I’m a Maritimer (technically a Blue Noser from Nova Scotia) and got to Wisconsin via a lot of moving. I did my BSc and MSc in Canada in Newfoundland and Saskatchewan, first came to the US for a job in California, then a PhD project in Alabama, a post doc in Maine and here.

Academically I came here via birds and herps (reptiles and amphibians) – this is my first time working on fish.

Pretend we just boarded an elevator and you only have a one-minute ride to tell me about your research – can you capture it a few sentences?

I’m working on figuring out where we can take out dams and road crossings to increase the amount of habitat for fish in the Great Lakes.
My project is pretty technical behind the scenes but it’s a really useful to other researchers and even the general public. We’re developing an online tool people can use on their own areas of interest (state, even specific watersheds) to figure out which barriers are worst for fish, so stand by for that to be released this spring.
Dams and road culverts (like this one in Ozaukee County, WI) are a big barrier to many species of migratory fishes. Photo: Matt Aho

Dams and road culverts (like this one in Ozaukee County, WI) are a big barrier to many species of migratory fishes. Photo: Matt Aho

 

Continue reading

Study Finds Ancient Aquifer Under Antarctic Lake

Despite existing in the extreme cold desert of Antarctica’s McMurdo Dry Valleys, there is liquid water beneath the permanently frozen surface of one of the valley’s largest lakes.

Lake camp, Antarctica

A new study published in Geophysical Research Letters says that, while this ancient, super salty aquifer doesn’t provide anything like the water humans pull out of the ground to drink or irrigate crops, it is a cozy habitat for all sorts of microbes.

Hilary Dugan.

Hilary Dugan.

Hilary Dugan, a post-doctoral researcher at the University of Wisconsin-Madison’s Center for Limnology, was lead author of the paper and says the research yields new information not just on the hydrology of Antarctica’s dry valleys, but even points to interesting parallels between life under the ice and life on Mars.

“We believe the aquifer beneath Lake Vida is a remnant of a time when the water levels across [the valley] were much higher than present. Upwards of 200 meters higher,” she says. “If you stand on the surface of Victoria Valley today, there is no indication of the amount of water stored beneath ground.” Continue reading

Field Samples: The Art (and Science) of Wrangling ‘Big Data’

Field Samples is a weekly Q&A asking researchers what they’ve been up to and what they’ve learned. Today, information manager/data scientist extraordinaire, Corinna Gries, talks the brave new world of “big data.”

Who are you, where are you from, and how did you get here? 

CorinnaGriesI am Corinna Gries, Information Manager for the North Temperate Lakes Long-Term Ecological Research (NTL LTER) site.  I was born and raised in Hamburg, Germany and went to school in Kiel, Germany where I received a PhD in Botany. How I got here is a long story that involves an early interest in databasing and programming, a self-taught career change while still doing botanical ecophysiology research, and a stop as information manager for the Central Arizona Pheonix LTER site.

Pretend we just boarded an elevator and you only have a one-minute ride to tell me about your work – can you capture it a few sentences? 

I archive data, which is sort of like running a museum or library for data. That is, the data are not in drawers, on shelves, or in display cases, but in a database and displayed on the web for everybody to find, download and use. This is a somewhat new discipline, called Information Management, Information Science, or lately Data Science and involves a fair amount of technical as well as science domain understanding. Continue reading

Fish Fry Day: How Do Fish Live Under the Ice?

While we’ve been spared (so far) by any sort of climate shenanigans like a polar vortex this winter, our lakes have had a nice thick cover of ice on for a month or more. And lots of people send in variations of the question – what’s life like for a fish under the ice?

Bluegill congregate under the ice of Long Lake in Minnesota. Photo: Fargo-Moorhead Dive News

Bluegill congregate under the ice of Long Lake in Minnesota. Photo: Fargo-Moorhead Dive News

Well, the short answer is “Not much different than the rest of the year.” They eat and breathe and try to avoid becoming lunch.

But there are some interesting elements to winter life, so we asked CFL grad student, Alex Latzka to help explain. Continue reading

Field Samples: Spiny Water Fleas, Lake Mendota, and Green Water

Field Samples is a weekly Q&A asking researchers what they’ve been up to and what they’ve learned. Today, CFL grad student, Jake Walsh, talks Lake Mendota and the invasive spiny water flea.

Who are you, where are you from, and how did you get to where you are now?

Jake Walsh taking a sediment core on Lake Gogebic on the Wisconsin/Michigan border. Photo: Jake Walsh

Jake Walsh taking a sediment core on Wisconsin’s Gile Flowage. Photo: Carol Warden 

I’m Jake Walsh, a PhD student with Jake Vander Zanden. I love watching the Minnesota Timberwolves play basketball (or what they’re passing for basketball now-a-days), playing tennis, long walks through my cruddy neighborhood with my wife and dog, and the occasional video game binge.

I’m from Hastings, MN (smaller town on the Mississippi south of St. Paul) and I got my BS in Biology at Hamline University in St. Paul. I got addicted to getting paid to go out boating while doing research with Dr. Leif Hembre at Hamline University. We were doing research on spiny water fleas’ effect on Daphnia’s stress response (elevated heart rate) and some genetics work on trying to track SWF’s movement across the Great Lakes Region.

This got me interested in

1) figuring out how I can get paid to enjoy lakes

2) how I make a career out of obsessing over zooplankton (I have since expanded my interests pretty substantially), and

3) how I can help provide insights into the problems posed by invasive species which naturally lead me to Jake Vander Zanden’s lab here at the CFL.

It wasn’t until I came and visited the CFL that I found out that SWF had invaded the lake in 2009. I swear that I had nothing to do with it. Continue reading

The Study, Science & Stories of Our Inland Waters