Wisconsin's Productive Fisheries

Sun sparkled off the calm surface of Lake Superior as I joined the line of Wisconsin Master Naturalist students waiting to board the Wisconsin DNR’s research boat. With iffy weather forecasts all week, we’d lucked into one of those bluebird days that lulls you into thinking that the greatest lake is not so big after all.

Earlier that morning, Wisconsin DNR fisheries biologist Dray Carl gave us a brief overview of management on Lake Superior. “Have you ever heard that old adage that 90% of fish are in 10% of the water?” he asked. “Well, the numbers may not be exact, but the Apostle Islands do hold some of the most productive waters in Lake Superior.”

The 1,332-foot deep waters of Lake Superior may be impressive, but only a few hardy species can survive in the abyss. In contrast, the relatively shallow water of the 1.28 million acres that Wisconsin manages—just 6.5% of the total area of the world’s largest lake—produce as much harvest as other, bigger jurisdictions. In particular, fish refuges set aside off the shores of Gull Island and Devil’s Island contain important spawning shoals for lake trout.

Within this productive fishery, there are many constituents to consider, and the DNR uses a blend of science and public input to strike a balance. Sport fishermen, commercial fishermen, tribal fisherman, and all of the related business and environmental values of a healthy lake weigh in.

Balance was also needed as our Master Naturalist crew stepped onto the DNR’s research boat, the Hacknoyes. “This is our office all summer!” bragged one of the crew as he showed us around. Soon we’d motored out to where they’d set a gillnet for us the day before. Gillnets are strung out like the net on a tennis court and weighted to the bottom of the lake. Buoys mark each end.  Fish swim in and get tangled.

Boarding the Hacknoyes. 

Captain Ross came down from the bridge and took up a new station next to the mechanical lifter. “Having a mechanical lifter to pull nets up is one of the single biggest things to advance commercial fishing,” Dray explained.

As we watched more than 120 feet of rope rise dripping out of the lake, we could understand why. Captain Ross stood by a window in the side of the boat and steered its course with a little lever by his right leg. While he steered, he also watched the line and eventually the net coming up out of the water to remove debris before it got on the boat. The rope, and then the net, was grabbed, spun, and then released onto a stainless steel table by the lifter. 

Dray and Randy, another crew member, coiled the ropes out of the way, and minded the net as it emerged from the depths. Finally, through the open window near Captain Ross, I spotted a whitefish coming up with the net. It spun around the lifter, too, then flopped onto the table where Dray made quick work of extricating it from the net.

Captain Ross minds the mechanical lifter as it pulls a gillnet full of whitefish out of Lake Superior. Photo by Emily Stone.

After Dray and Randy removed about a dozen whitefish from the net and tossed them into a tank of water, they collected data on the fish. The first two shimmering, white torpedoes were still alive and kicking. Dray measured their lengths and attached numbered plastic tags before tossing them back into the lake. If these fish are re-caught, fishermen return the tag to the DNR to learn more about its travels and age. The other fish had died from the stress of being pulled quickly. Typically, 95% of fish in their research nets survive.

Wisconsin DNR fisheries biologist Dray Carl shows some Master Naturalists the inner workings of a whitefish.
Photo by Emily Stone.

The dead ones offer more information, though. Dray skillfully slit open their heads to clip out the otoliths—their ear bones—which record their age just like rings on a tree. The fish are then field dressed and put on ice, ready to be delivered to the Bodin Fisheries processing plant. Back on shore, we followed those fish to Bodin’s and saw the fillet machine, the skinning machine, the smoker, and the huge coolers where fish are readied for a visit to your dinner plate.

The skinning machine is a true feat of engineering. The sin side of each fillet freezes to a drum, and then a super sharp knife slices the fillet clean.

Fish and fish guts not destined for human consumption get taken over to the Hulings Rice Food Center at Northland College, where their carcasses add valuable nitrogen to a high-tech compost bin. Local farmers use the compost to produce even more delicious food near the Apostle Islands. In the Northland College cafeteria, both local fish and local produce fill students’ dinner plates.

On Northland College campus they grow vegetables in compost made from food scraps, fish guts, and more. 

Our full day spent near the calm and sparkling Lake Superior only reinforced our feeling that the greatest lake might not be as big as we thought, especially once it’s clear just how tightly everything is connected.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit and Pollinator Power annual exhibit are now open!

The Smell of Rain

Throughout the morning, the fluffy white clouds grew larger and more numerous, cluttering up the blue sky. The temperature on the bank sign rose sharply from 40 degrees in early morning, up to 77 degrees by early afternoon.

After lunch, I stepped outside to run errands. A blast of hot, humid air washed over me as I opened the door. We just finished winter with a blizzard, and now it is summer! Then the rain began to fall. I stood under the overhang and watched as huge, splashing, cold drops plunged down through the warm air. Now it not only felt like summer, it smelled like summer.

Rain falls on rocks and water in the Boundary Waters. Photo by Larry Stone.

You have probably smelled it, too: that sharp, pleasant, green scent of rain on dry earth. Those same wonderful odors will even rise up from concrete and asphalt. This smell has a fancy name, and also a biological explanation. The name is “petrichor,” which comes from the Greek word for rock (petra), and their word for the fluid that flows in the veins of the gods in Greek mythology (ichor). You are smelling the blood of the gods sprayed up from the rocks. It is defined as "the distinctive scent which accompanies the first rain after a long warm dry spell."

This wonderful word was coined in 1964, by Isabel Joy Bear and R. G. Thomas, two Australian researchers who discovered that the scent originates from an oil which plants produce during dry spells to retard seed germination and early plant growth. This may be an adaptation plants use to limit competition during times of low moisture. Rain washes the oil away, stimulating germination and growth again. During the dry spells, the oil may also be absorbed into rocks and soils. Falling raindrops liberate the compounds from both plants and rocks, and fling them into the air we breathe.

The rain tapered off, and I walked down the street on my errands. From the bare soil in expectant flower gardens, another scent rose up to meet my nose. This earthy aroma is characteristic of healthy, post-rain soils, and sometimes is even included in perfumes. The name for this scent, “geosmin” also has a Greek origin (combining the words for earth and smell) and a biological explanation.

Geosmin, an organic compound, is produced by several classes of microbes in the soil, including cyanobacteria (blue-green algae) and actinobacteria (especially Streptomyces, which are important to medicine as a source for antibacterial and antifungal agents as well as anticancer drugs). The organisms thrive when the conditions are damp and warm, and create geosmin as a byproduct of living. In an effort to reproduce before they dry out, the bacteria also release geosmin-scented spores. Rain flings these compounds into the air, just as it does with petrichor, and we smell “earth.”

Smelling that wonderful earthy smell is one thing, but tasting it is quite another. Beets, some wines, and bottom feeding fish like catfish and carp all derive their characteristic earthy flavor from geosmin. Some folks like it, and others don’t. Even the water we drink can be tainted with the flavor, though it will not hurt you. Human taste buds are very sensitive to geosmin, and the average person can detect it at a concentration of 0.7 parts per billion. The human nose is even more sensitive, and is able to detect geosmin at concentrations as low as 5 parts per trillion.

In deserts, the presence of geosmin usually indicates water. Camels may follow the scent to an oasis, and then disperse the spores to new places on their travels. Some cacti scent their flowers with geosmin, thereby attracting thirsty insects who are tricked into serving the plant as pollinators. Closer to home, some biologists suspect that petrichor, washed into streams by rain, signals spawning time for freshwater fish.

In Australia, aboriginal people associate geosmin with the first life-giving rains of the wet season, and with the color green. So important is this smell that geosmin perfume, rubbed onto their bodies, serves as a symbolic connection of body and landscape. According to research done at the University of Queensland, “The odor is believed to be protective and cleansing, linking present generations to their ancestors.”

Rain is grace; rain is the sky descending to the earth; without rain, there would be no life. -- John Updike

Without rain, we could not smell petrichor, geosmin, the blood of the gods, the scent of the earth, the link to generations past. Without rain, we could not smell summer.

Soon the clouds thinned and dispersed, the pavement dried, and the sun shone. The smell of summer lingered on the breeze, and lilac buds began bursting with green in their effort to catch up!

This article was originally published in 2013.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit and Pollinator Power annual exhibit are now open!

A New Bee in Denali

On one of our few sunny days in early May, I took a scenic drive to Juniper Rock Overlook on the North Country Trail, hoping to find early spring wildflowers starting to bloom. On the way, I parked at a boat landing and crossed the road to explore the haze of yellow brightening a wet ditch.

The oblong catkins of willows may not have showy petals like bloodroot or hepatica, but these flower clusters produce brightly colored pollen and abundant nectar. Most trees that produce catkins depend on wind to spread their genetic material. Aspens, poplars, birches, hazelnut, and alder are some local examples. In contrast, some willows rely on insects for pollination, and early spring insects rely on willows for food before other flowers become abundant. I was pleased to see that several orange-belted bumble bees were foraging on the willows. These queens had survived the winter, emerged from the ground, and were gathering resources to start their colony.

Willow and bees go well together all over the world. Last June I went looking for bees among the 17 species of willows in Denali National Park, Alaska. Having just built the Museum’s 2018 “Bee Amazed” exhibit, I had bees on the brain. So I signed up for the “Insects of Denali” field course run by Alaska Geographic. In contrast to my sunny hike up Juniper Rock, the late June weather in Denali was damp and cold.

One of the instructors, Jessica Rykken, is Denali National Park’s official entomologist. She is charged with surveying, collecting, and archiving insects. Jessica brought our small group of teachers, citizen scientists, and naturalists to a few of the plots her research team, including University of Alaska Fairbanks graduate student Adam Haberksi, set up to study “patterns of arthropod diversity across habitat type and along elevational gradients in Denali National Park.” This work will be the basis of Adam’s Master’s thesis.

Next to a sophisticated data logger that records the air temperature at regular intervals, each insect plot had a smattering of blue, yellow, and white plastic cups held aloft on wire stands. I often chuckle at the juxtaposition of highly technical and homemade gear that scientists use. The cups were filled with propylene glycol, a syrupy food additive that preserves any insects that meet their demise.

Jessica showed us how to collect insects by pouring the bug soup we found in the traps through little tea strainers. We topped off the cups with more propylene glycol from a jug before placing them back in the stands. The soggy insects were dumped unceremoniously into carefully labeled sample bottles for processing back at the lab. Although the insects looked like little drowned rats, a few of them could be identified as bumble bees based on their large size and furriness. Between Jessica’s work and that of earlier scientists, 17 species of bumble bees have been recorded in Denali National Park. That’s more than one third of the bumble bee species in all of North America!

Since the hotbed for bumble bee diversity lies in the rugged terrain of the Himalayas and Alps, it’s no surprise that they can thrive in Alaska (and northern Wisconsin!), too. Their ability to produce heat through shivering, combined with a large body size and a thick coat of hairs to retain that heat, gives bumble bees an adaptive edge in cold places.

Their warm fur looks pretty sad when it’s covered in syrup, though. In order to get her bee specimens looking spiffy (and identifiable) again, Jessica and some graduate students put the bees into Mason jars with warm water and a dab of Dawn dish soap. After about a minute of shaking, the bees are clean and amazingly unharmed. Jessica rinses them, drains off the liquid, and points a regular old hair dryer into the jar to reinstate their natural, fluffy condition.

After a morning on the mountainside in a cold drizzle, our field course might have appreciated the same treatment. Instead, we hiked higher up into the tundra on Primrose Ridge and checked more of Jessica’s insect traps until the sun finally came out.

Once the bee specimens are dry, they are pinned into cases and brought to the Museum of the North at the University of Alaska, Fairbanks. Derek Sikes, the Curator of Insects and the other instructor on our field course, gives each specimen a barcode before carefully storing them in state-of-the-art cabinets. While Derek, a beetle specialist, would need a few extra lifetimes to study the collection’s almost 2 million specimens, he often fills requests from other researchers.

Several years ago, Paul Williams, a bumble bee expert at the Natural History Museum in London, noticed that some of the specimens of Bombus neoboreus he was looking at didn’t match up. After sequencing their DNA, Williams put out a request for curators to send him more specimens identified as this black-tailed species of bumble bee. Derek mailed him all of the B. neoboreus from 2012, Jessica’s first summer of research in Denali.

After both DNA work and painstaking morphological measurements, Williams identified three of Jessica’s bees as an entirely new species: Bombus kluanensis. Williams named it after Kluane National Park in Canada, which abuts Alaska and is the only other area where it’s been found so far. The first specimens were collected there in the 1970s, but were also misidentified as B. neoboreus. Before this discovery, it had been almost 90 years since a new species of bumble bee was discovered in North America.

Specimen from the collections of the Natural History Museum, London

Jessica told us this story on the tundra-covered slopes of Primrose Ridge where she’d collected those three specimens of the new species.

From data loggers to plastic cups, from dish soap and hair dryers to barcoded specimen cabinets, and from DNA sequencing to soggy researchers slogging through willows, I love the way that science can be both fancy and folksy. It reminds me a little of the contrast between the bloodroot’s showy flowers and the modest catkins on willows. Both are important parts of the spring woods. All of these are good for bees.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit and Pollinator Power annual exhibit are now open!

Field Trip!

“Come look at the beautiful garden I planted,” I tell 25 first graders on a sunny morning. Pointing at oversized photos of tomato, pumpkin, strawberry, and milkweed flowers on the ground, I continue. “All of my flowers need to be pollinated in order for my garden to grow the food I want to eat. I’m going to turn you all into bees so that you can help!”

After a few more instructions, I give the “ready, set, go!” and the swarm of kids runs off down the playing field. Each “bee” carries one piece of colored-paper-pollen to the other end, and deposits it on a matching set of flower photos. There are no winners. There are no losers. No one is “it.” But the kids are burning off a lot of excess energy by running around like bees. After a full minute of sprinting, the learning begins.

I gather the kids at the far end and check their work. Each type of flower has a unique color of pollen, so I can make sure that they brought pumpkin pollen to the pumpkin flower, and not to the tomato flower. There are a few odd colors mixed in here and there, but mostly the kids match the pollen to the correct flowers.

Students who visit the Museum on a field trip this spring will play several different games about bees and pollination.
Photo by Emily Stone.

This is one of the most important concepts I will repeat like a broken record throughout our field trip season: pollination only works when pollen from one flower gets transferred to another flower of the same species. In reality there are exceptions for self-pollination within the same individual flower, but the main point is the same. Pollen from a different species is just dust.

Another idea that I want to cement into their little brains, is what pollination does. “Pollination helps plants grow,” sounds like fingernails on a chalkboard to my ears. Perhaps it’s because of my graduate professor who kept asking “how” during a discussion on how trees grow, or perhaps it’s because I know this answer hides a lack of true understanding.

Obviously I don’t expect first graders to understand complex biological processes, but I’ve also encountered plenty of teens and adults who think pollination “helps plants grow.” It’s not entirely wrong if you stretch the words far enough, but I’m pretty sure that the image going through their heads is pollen raining down like fertilizer on a growing plant.

Pollen isn’t fertilizer, though. Pollen contains the male reproductive cells of a plant. Pollination is when those male cells get transferred to the female part of the flower. If all goes well, the pollen then fertilizes the ovule and produces a seed. I don’t tell the first graders, of course, but this is sex in the garden.

If my graduate professor started asking “how,” we’d be here for weeks discussing the intricacies of pollination, fertilization, and seed production. But at least this answer is more specific than “it helps plants grow.”

For plants, the goal of pollination is to produce seeds. Often, those seeds are encased in something yummy—pumpkins, tomatoes, strawberries, or apples, for example. So, pollination does help plants grow—but only NEW plants, sprouting from those seeds. It also helps fruit grow, and my pie-filled belly.

To illustrate this point with the first graders, I show photos of the foods that our young “bees” helped create: a pumpkin pie, a strawberry, and a bottle of ketchup. Not many first graders think that eating a ripe tomato is very exciting, but a cheer goes up for ketchup. The milkweed is a little different. For that I share a photo of a monarch butterfly and a caterpillar. Pollination is important to humans, but it’s essential to the rest of nature as well.

Several more games later, when I’m sure that the kids understand these concepts—at least for today—I take them into the exhibit hall. Our main Pollinator Power exhibit has plenty of fun ways to discover more about bees, wasps, butterflies, moths, flies, beetles, and hummingbirds. From a light-up matching game; to a marble drop that uses puck-like pieces of “pollen” to create blueberries and primrose seeds; and a food counter where kids can serve up their favorite pollinator-dependent food, the colorful exhibit inspires exploration.

Of course, no such adult-friendly exhibit can compete with our brand new Curiosity Center kids’ area. We brought in the professionals for this one, and the resulting exhibit is durable, washable, beautiful, and FUN. Right out of the gate, kids run for the spiral staircase hidden in the center of a giant tree. Some get distracted by the “periscope” camera inside the tree that affords them a bird’s-eye view of their friends. Others opt for the true bird’s-eye view, and climb up the tree and out into the giant bird nest. A big red button calls to them like a siren, and one good smack releases our flying squirrel, Luna, to go soaring across the room on her zip line.

The new Curiosity Center kids’ area at the Cable Natural History Museum is a big hit with the school field trips as well as visitors.
Photo by Chris Frasch.

It’s no accident that our field trips are filled with games and play time. I want the kids to understand pollination, of course, but I’m also hoping that the seeds we plant today will grow into a life-long belief that learning can be fun.

Emily’s second book, Natural Connections: Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent bookstore, too.

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity Center kids’ exhibit and Pollinator Power annual exhibit are now open!