by Riley Steinbrenner
It was 7:50 when I woke up one Friday morning to my phone’s alarm blaring the most obnoxious tone available via iOS.
After realizing I indeed wasn’t on a submarine at war in the middle of the Pacific, I clamored out of bed and into the kitchen where I poured myself a cholesterol-free helping of Cheerios into the deepest ceramic bowls occupying Juday House’s pantry.
While spooning heaps of the banana-topped cereal in my mouth, I gazed outside the kitchen window where trees swayed in the darkness of an unusually overcast morning.
“Huh, this doesn’t look good,” I thought. Grabbing my phone, I sent a message to my housemate.
“Hey Camryn! Do you know yet when you guys are headed out to Trout? Last night Syd told me 1, so just checking:)”
For 36 years, Trout Lake has served as one of seven northern Wisconsin lakes monitored by Trout Lake Station scientists for the National Science Foundation’s North Temperate Lakes Long-Term Ecological Research project, or NTL-LTER. The NTL is part of a network of more than two dozen U.S. study sites and the only one dedicated to lakes. There are also four study lakes in southern Wisconsin that fill out the NTL’s full research load.
Every summer, two undergraduate students are hired to join the LTER “base crew” and help collect data from the seven northern lakes. These data have been used nation-wide for research projects in the fields of limnology, biology, hydrology and chemistry, just to name a few!
Under the supervision of TLS staff Pam Montz and Tim Meinke, this summer’s LTER base crew is made up of undergraduates Sydney DeMets from Lawrence University and Camryn Kluetmeier from Middlebury College.
“If Trout is an afternoon lake then yes. I can give you a definite answer in about 15 minutes!” Camryn responded.
Given the morning’s gloomy weather, I slowly finished my breakfast and put away the stack of clean dishes that towered in the drying rack. Mid-stack, my phone let out a piercing DING! from the kitchen table.
“It’s a morning lake, so we’ll probably head out a little after 9.”
Current time—8:34 am. Current ensemble—pajamas.
I sprinted into my room, pulled on a pair of jeans, hoodie and shoes, and grabbed my camera and notebook. Before heading out the door, I snatched a plastic Trig’s grocery bag.
“This might come in handy,” I thought, looking at my camera and thinking about the clouds.
With two minutes to spare, I ran down the trail from Juday House to the station and found Sydney and Camryn hauling equipment up and down the stairs from the lab to the dock like ants having a field day at a picnic.
“Hey!” Sydney replied, “We’re just loading equipment into the boat right now.”
Following Camryn into the wet lab, we filled our arms with what was left on the floor. Three trips to the dock later, the boat was ready to go.
Climbing over the pile of life jackets, nets and data monitors, Camryn inched her way towards the bow of the boat while Sydney lowered it from a lift on the dock.
With a counter-clockwise push off the white wheel that held the boat inches above the water, we watched as it slowly settled down.
“Oh, wait!” Camryn yelled suddenly. “The plug’s not in!”
Sydney lurched forward to catch the wheel, preventing the boat from lowering any further while Camryn fastened the plug into the drainage hole below the motor.
“Last time, we forgot to check the plug and the boat started taking on water in the middle of the lake,” Sydney said with a nervous laugh at the memory, which surely would’ve won them the CFL’s annual “broken prop award,” a gag trophy awarded at the annual Christmas party to whichever research team caused the most damage that summer—no joke!
After lowering the boat, Camryn gave a few tugs at the motor to get it started, and soon enough we were on our way to the sampling location.
On our trek across Trout, Sydney explained that they collect data on the seven LTER lakes around station five days a week, rain or shine. In order to reduce bias, such as fluctuations in water temperature throughout the day or even human error, the day and time that they monitor the lakes are randomized every week.
“So, where do you guys do the data collecting on Trout?” I ask as Camryn seems to be to driving us nowhere fast.
“At this really deep hole that comes out of this point,” Sydney replied, giving the general direction with her outstretched right pointer finger. “We’re looking for white buoys.”
I turned around in my splash-zone seat on the bow of the boat to get a look.
“Okay, this might be tricky,” I thought, taking in the turbid lake that the wind peppered every few seconds with white caps—small, but enough to look like the buoy we were searching for.
“Oh there it is!” Sydney exclaimed as she got up from the middle seat to the bow. “Riley, let’s switch seats. Camryn, can you slow down?”
Over the wind and wake, Camryn must not have heard her, because as soon as Sydney reached for the buoy, a white cap broke against the bow—showering her neck up.
“I’m so sorry, Syd!” Camryn yelled from the other end of the boat as she slowed down.
“We gotta back up!” Sydney responded. “The buoy’s under the boat!”
After relocating the buoy in the unrelenting waves, she was able to successful attach the buoy with a hook tethered to our boat.
“Phew!” Sydney let out as she whipped her damp hair around with an uncomfortable yet determined look across her face like she was on an episode of Dirty Jobs.
Taking refuge from the splash zone, Sydney eased her way to the middle while I climbed over to the back next to Camryn.
“Whoa! These waves are kinda crazy!” I shouted as the two prepped their equipment, turning our little motor boat into a floating lab with tubes streaming over the edge into the water and monitors awaking from the dead in their portable brief cases.
“If you get seasick, just look at the shoreline.” Sydney said over her shoulder as she clamped a 1000-mL graduated cylinder to a metal rod-stand. “That’ll help reorient yourself.”
“Let’s just hope we can still see the shoreline!” I thought as the morning drizzle seemed to be getting heavier.
Looking over to my right, Camryn hunched over her lap, recording today’s timestamp on the water-resistant data sheets.
“‘On station time,’ we’re gonna call it…9:30.” For recording data, especially LTER, it is important to clearly indicate the time of day the samples were collected.
This week, Sydney explained, was “bio week.” She and Camryn would collect samples that deal with each lake’s biology – catching zooplankton in a net, for example, or measuring chlorophyll (which can be used as an indicator of algae growth) at predetermined depths that have been used as guidelines by LTER for decades.
“At least you aren’t here for sediment trapping!” Sydney said, referring to a sampling technique used to dredge the bottom of lakes during chemistry week. “Camryn, what’s one word you would use to describe the sediment trap?”
“Eeeevil,” Camryn responded in disdain.
“How bad can it be?” I wondered, but that’s for another day!
After refocusing myself from a sediment-trapping daydream (or, daymare?), I looked over to see Camryn already at work lowering a black wire and yellow wire, along with a rope marked with yellow flags to mark each meter, over the boat’s edge into the water.
“Ooooh, what’s that do?” I ask.
“This is a light profile,” she responded. “It measures the amount of light available down the water column.”
“So, it’s like a higher-end Secchi disk?”
Unlike a Secchi disk, a light profile provides more precise measurements on how well light travels through the water; thus, providing an indication of water clarity. Looking over Camryn’s shoulder as she lowered the sensor slowly one meter at a time, the number that measures light penetration steadily dropped.
“Tim [Meinke] has seen numbers starting off in the thousands,” Camryn said. “But it’s a cloudy day so it started pretty low. I stop until the number reaches below one.”
This indicates that light can barely penetrate at this depth, so LTER determined that number to be the cut-off point, which Camryn reaches at just 13 meters—or 43 feet—below the water’s surface. On a sunnier day, the penetration point would be much deeper.
As Camryn recoiled the light-profile wires, I looked over Sydney’s shoulder— in front of me—to see what she was up to.
Holding the 1000-mL graduated cylinder in her right hand and a dripping, familiar-looking plastic piece in her left hand, she explained she was filtering chlorophyll using a geopump.
The geopump uptakes a specific amount of whatever is in the water at any given meter, including algae. Chlorophyll is what gives aquatic plants like algae their green pigment. Therefore, Sydney said, by filtering chlorophyll from the lake, she and Camryn will be able to determine the “green-ness” of the water.
“Oh that’s it!” I thought, remembering Kaela used the same plastic piece to filter bacteria from her bog samples.
Like the light profile, Sydney pumped chlorophyll from the lake at predetermined depths. For each depth she replaced the end of the tube with a new piece of filter paper. Next week, she said, they will examine the filter-caught chlorophyll in the lab to get a better understanding of the lake’s health.
While the geopump continued filtering chlorophyll, which took a few minutes at a time, Sydney leaned to her left side where a dissolved-oxygen/temperature monitor was in full swing. Just like Kaela did at Trout bog, Sydney measured the DO and temperature at every meter for 33 meters, or about 108 feet—the depth of Trout at our location.
“If you think about it, 32-33 meters is about ten stories,” Camryn said, prepping her next piece of equipment to sample zooplankton. “It’s like we’re on top of a skyscraper!”
“Oh…I uhh…never thought of it like that…” I said nervously while looking over the edge of the boat, which didn’t really add to the effect considering it only look like we were one story off the ground. Thanks, light profile!
With that pleasant image in our heads as we rocked atop the rickety “Trout Tower,” Camryn spun around in her seat to unzip a long, red-tarped contraption that out-measured the width of our boat by a foot.
Zooplankton are almost always at the bottom of an aquatic food chain, so the types of zooplankton that live in a lake say a lot about the type of fish that live there. Essentially, they are the canaries of lakes. If their populations go through radical changes or die-offs, much of the fish populations that thrive there will feel the impact.
A Schindler-Patalas trap is one of the many methods used to sample zooplankton, and one of the most accurate. Camryn explained that, unlike most mesh-zooplankton nets–which sample the whole water column–the Schindler-Patalas trap takes a sample of just one meter of water, draining it into a cup attached to the end.
By extracting nine different samples from predetermined depths, Camryn and Sydney will “pool” the samples in lab, taking a higher percentage of subsample from the top-meter sample and decreasing the percentage of subsample taken from deeper samples. This method mimics the upside-down “dome shape” of a lake, as more subsample is taken from the top-meter sample—the high-surface area part of the lake, where more zooplankton exist—and that area decreases as sample depths increase.
Grabbing the handle at the top and holding onto the rope attached to a hinged door at the bottom, which will enclose the meter of water inside, Camryn dropped the trap in the water. The plexiglass box sank below the surface. When it completely submerged just under the water edge’s, Camryn pulled the rope and brought the trap back aboard.
The trap got eight more dunks in the water, with each trapping one-meter of water at a deeper depth.
Between each dunk though, Camryn unscrewed the cup containing the fresh sample caught at the end of the trap. Holding a glass jar of ethanol—a nail-polish-smelling solution used for preservation—between her knees, she emptied the sample using a stream of the solution to get every last zooplankton, and deposited the jar in a lunchbox of a storage container.
After repeating the process eight more times, and returning the Schindler-Patalas trap back to its case, Camryn checked on Sydney’s progress.
“How’s it goin’, Syd?” she asked.
“Oh good, I just don’t feel too well…” Sydney replied, now hunched over with her hood over her head. “I need to do some mental regrouping when we get back, or throw up in the bathroom.”
Sydney toughed it out though, true base-crew style—and I wouldn’t be surprised if she refused to throw up overboard to prevent “ruining the data.” Who knows, these Trouters are passionate researchers!
While Sydney chugged along collecting her DO/temperature and chlorophyll samples, Camryn proceeded to a second method of sampling zooplankton.
“This is a Wisconsin net,” she explained, lifting a cone-shaped net out of a bag near the motor. “It samples zooplankton from the entire water column after it’s dropped at a predetermined depth. We only do this one two times, though.”
After unraveling the net, Camryn tossed it over board, counting off the flags that lined the net’s rope until it sank to the bottom the lake. She then proceeded to hoist up the elevator full of zooplankton who live on all ten floors of Trout Tower.
As with the Schindler-Patalas-trap sample, Camryn stored both Wisconsin-net zooplankton samples in ethanol.
“Since it’s bio week,” Camryn said as she packed away the samples, “we’re going to do a spiny-water-flea tow!”
Spiny water fleas are an invasive species that have recently been found in Trout Lake, but since there’s no magic solution to rid of the tiny pests, the best protocol is to clean off any equipment used on the invaded lake—such as fishing lines and boats—and monitor their population.
Using a cone-shaped net similar to a Wisconsin net, but with bigger mesh holes—since the spiny water fleas are bigger than the native zooplankton—Camryn let the net fly. Carol Warden and Al Wirt of the DNR also used this technique to sample for the invasive species on Sparkling Lake.
Unlike with the zooplankton samples, however, Camryn filled the spiny-water-flea sample jars with Trout water, as using ethanol would kill them.
With the spiny-water-flea sample packed away, she had just three more measurements to conduct: water clarity, temperature and wind speed. After tossing the Secchi disk in the wind-churned waters, Camryn held an Aqua-Scope tube just below the water’s surface like a reverse periscope to get a better look at the disk as it disappeared.
“4.4 to 4.1 meters,” she said, recording the parameter indicating water clarity.
Pulling out the smallest pieces of equipment on board, Camryn measured the temperature using a mercury thermometer and the wind speed using a Dwyer instrument.
“16 degrees Celsius…12 miles per hour from the west,” she recorded.
As Camryn packed her equipment away, I crawled over the middle seat to find Sydney just three more depths away from finishing her chlorophyll samples.
“Almost dooone,” she winced, dumping the excess lake water that gathered in the graduated cylinder back into the lake—two left now!
After several more minutes of churning from the geopump, and dancing from Camryn in the back (to keep warm, of course), Sydney finished the chlorophyll samples and tucked in the geopump inside its water-resistant case.
Although every part of the boat became a splash zone, the trip back seemed to be quicker than the trip there. “It’s moments like these you start to appreciate the more mundane things in life, like seeing the dock as you approach shore,” Sydney said, managing a smile as the highlighter-yellow platform welcomed us to station.
by Riley Steinbrenner