Cobbles, Boulders and Sand, Oh My!

Week 2. We’ve passed the “is-my-snorkel-on-right” and “We-found-some-mussels-oh-wait-they’re-rocks” stage of the project, and now we’re on to real study sites data collection! A large part of this involves sediment, or as Dan likes to call it “dirt” (technically inaccurate though). Check out a sediment sample below!

The sample you’re looking at originates from a specific site along the Snake River near Mora, MN. However the sample above only represents a portion of the river bed. Below are two examples from the same site along Snake River.

This contrast is part of what makes sediment interesting. Although these samples were physically close to one another, the amount of mussels present varied.

What are some factors for variability?
energy in the river system

channel placement

bedrock/rock sources

biological influences

human influence

These all play a role in creating how the bed of a river looks and who is able to live there. Stay tuned for some sediment stories!

Why Research Mussels?

When you look at a river, the first thing you think of is probably not the small invertebrates living within it. But there is a lot more going on under the surface than you might expect.

Freshwater mussels are just one component of a diverse and complex ecosystem. Together, these parts allow us to enjoy the many benefits of a healthy river, from canoeing and fishing to taking in a great view. In ecology, perks that people get from an ecosystem are called ecosystem services, and you might be surprised by the variety of ways mussels are in your life.

Historically, mussels have been an important material used in making buttons thanks to the pearly insides of their shells. While buttons today aren’t made of mussel shells, mussels are still used in the pearl industry. Shells of freshwater mussels are also important beyond their use as pearl-making machines, and are even important culturally. Their many colors, shapes, and sizes are key to their ornamental role. Who can resist picking up shells from the side of a riverbank!



Photo Source: Thad Allender http://www2.ljworld.com/photos/galleries/2007/nov/05/freshwater_mussels/

And of course, mussels directly influence the river systems they live in! Their filter feeding improves water clarity, signaling when a water system may be contaminated. This makes them a great indicator species for environmental conditions as well as enhancing the beauty and cleanliness of our rivers.They physically modify the habitat by burrowing down into the substrate and taking up that space, which can also move sediment around. Mussels also can anchor nutrients by excreting organic matter in the form of waste into the substrate, preventing everything being swept away downstream.

A site on the Snake River where we collected mussels this week.

Clearly, there is more to mussels than the average Minnesotan might assume. And because upwards of 70% of our native mussel species are threatened or endangered, it’s important to understand where mussels live and what they do. Keep reading our blog as we investigate these questions and continue Mission: Mussel.

Meet the Students

Welcome to our blog! We are excited to document our summer in the Hornbach/MacGregor lab at Macalester College! But who are we?

MAYA

Hi-ya, I’m Maya! I’m a senior Biology major and almost Japanese minor. I’m from La Crosse, Wisconsin and I enjoy petting puppies, seeking free food events, taking naps, people watching, and hanging out with my rice cooker. My favorite invertebrate phylum is Arthropoda, but there are some outstanding Mollusca members as well. I do not enjoy things with more than six legs (other than millipedes and crabs). I am interested in conservation biology and learning how to apply other disciplines to biology, which got me excited about researching native freshwater mussels this summer. So far, my favorite mussel is the Three Ridge (Amblema plicata)--it constantly defies expectations and can have more than three ridges! My favorite color today is slaty blue.

 CLARA

I’m Clara! I’m a senior Biology major and unofficial art minor. I’m from Arlington, Massachusetts. I like rowing, biking, pesto, camping, gummies, denim on denim, water bottles, and my favorite phylum (besides Mollusca, of course) is Cnidaria--gotta love those siphonophores! I really enjoy exploring the boundary between science and art (although I don’t really think there is one) and discovering how each one can communicate the same ideas in such different, and yet such similar, ways. I love being outside, especially doing scientific research related to wildlife and conservation, and the mussel project seemed super cool--the wet suits are just a bonus! My favorite mussel is definitely the Wabash pigtoe (F. flava) and my favorite part of this project so far is watching mussels stick their little squishy feet out of their shell to lick their neighbors. You can often find me watching my basil plants grow and protecting them from hungry housemates. I’m super excited for this summer!!

 BROOKE

Hi, I’m Brooke from Stillwater, Minnesota. I am a Junior Geology major and math minor here at Macalester. I first became interested in this project because it provided an opportunity to combine multiple fields of science (geology and biology), and a chance to study the health of Minnesota’s native mussels and the river systems they live in. Prior to this project, I knew little to nothing about mussels, but after some time spent in the field, the heelsplitter mussels have become my favorite. My geology side wants to say my favorite mineral - olivine. I enjoy spending free-time playing volleyball and going to the lake!
 

MOLLY

Hey all!

Molly here. Who am I? Well...

I grew up collecting agates and eating “world famous” pie in tourist town Two Harbors, MN, along Lake Superior. My interest in rocks metamorphosed into a full-fledged college career, as I am now a Macalester senior majoring in Geology. When I’m not draining my snorkel nose piece of water, I can be found collecting fossils by the Mississippi, grocery shopping, and trying to learn languages. Favorite color: orange. Another thing that is incredibly important to know is that I love steamed broccoli. My interests in this project developed as a junior, when I learned about river processes from a more geological standpoint. I am excited to now look at river systems with both a biological and geological focus in mind. What I really like about mussels so far, is that while they may feel like rocks sometimes, they’re actually alive (which is not a normal occurrence for the average geologist!). Favorite mussel: any heelsplitter variety!

Stay tuned for our many mussel adventures to come!