FoodWeb

Middle School Students Explore Lake Tahoe’s Aquatic Food Web

What would happen if all the zooplankton were removed from Lake Tahoe?  More than fifty middle school students explored this and other compelling lake ecology questions during a food web activity at the Tahoe Environmental Research Center (TERC) in January. Working with TERC staff and Kevin Beals, a Curriculum Specialist at the Lawrence Hall of Science, students investigated the complicated interdependence of organisms in lakes.  They began by modeling scientific observations using an ‘I Wonder / I Notice / It Reminds Me Of’ framework to analyze 2D and 3D images of aquatic organisms like Daphnia and the non-native Mysis shrimp

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Then students worked together to create a model of the Lake Tahoe aquatic food web.  Starting with the lake producers (algae and plants), each pair of students reasoned out where their assigned organisms reside in the web.  The end result was, like the actual Tahoe food web, quite complex.

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Taking it further, the students made predictions about how the removal or addition of one organism in the ecosystem could have an enormous impact on the whole system.  Kevin presented examples of ecologic challenges that Lake Tahoe managers have faced in the past.  For instance in the 1960s, lake managers introduced Mysis shrimp to Lake Tahoe with the intention of increasing the fish population.  It turned out that the fish rarely ate the Mysis, but Mysis did eat Daphnia, a primary food source for Tahoe’s native fish population, resulting in the opposite effect as intended.  Students began to understand how even well-intentioned ecological interventions can have unexpected and sometimes negative consequences.

The students reported that they really enjoyed the Food Web activity because they were able to ‘actually do something’ and they liked thinking through the chain of cause and effect in the same way that scientists do.  For future iterations of the activity, we plan to integrate viewscopes and other 3D visualizations to further explore how 3D technology can be used to impact STEM engagement with and understanding of freshwater ecosystems.

In addition, many scientists, like this group at the University of Chicago use 3D (or higher dimension) food web models to better uncover the myriad connections between species and more accurately predict how ecosystems will respond to changes like species invasion or climate change.  Perhaps future versions of the Lake Tahoe food web activity could incorporate 3D lake food webs to test whether 3D models are more effective than 2D webs at fostering student understanding of freshwater ecology.

Sandbox Mountain

Augmented Reality Sandbox Images Now in NSF Multimedia Gallery

There are 19 images in the series:  each image has a detailed description for what aspect of the sandbox experience the user is viewing .   The first image can be found here: http://www.nsf.gov/news/mmg/mmg_disp.jsp?med_id=75573&from=mmg  

To view the rest of the images either click on the next image (the link to the next image can usually be found at the end of the 2nd or 3rd paragraph in the current image’s description).  Or, search for Augmented Reality Sandbox in the gallery’s search: http://www.nsf.gov/news/mmg/mmg_search.jsp

This hexacopter can fly for about 10 minutes per charge.

3D Camera Technology and Filming Tahoe

3D works best for scenes that show depth, action, and a sense of awe. Flying between mountains, skimming the surface of the lake, or going deep underwater are the quintessential 3D shots. Shooting these aerial scenes used to require a crazy and highly skilled camera person with an equally crazy, skilled pilot. But given the demand for 3D video, it’s no surprise that inventive people created gadgets where once dangerous shots can now be safely taken with remote controlled hexacopters.

For our new 3D movie about Lake Tahoe, we’re able to collaborate with people who can get these beautiful, dynamic shots.  The next 3D experience at TERC will feature Tahoe underwater.  As our own Heather Segale noted in her article for Lake Tahoe News, we’ll still use tried and true divers to get many underwater shots.  Brant Allen and Katie Webb will dive into Tahoe with 3D cameras (generously donated by Go Pro) this spring to give viewers a unique look into Lake Tahoe’s depths.  They will be guided by Steve Andersen, a 3D movie specialist based out of Tahoe.  He created a weighted 3D camera that can sit in a shallow stream and film Kokanee salmon as they swim past. This simple device doesn’t compare, though, to his other wickedly cool 3D camera gadgets that can get beautiful aerial shots without risking life and limb (pictured below).  He attended our winter meeting at the Tahoe Environmental Research Center in Incline Village, NV, to show them off!  We were all very impressed with his creative solutions and ability to get the perfect shot.  We look forward to working with our collaborators and hope we can create a fantastic experience for the visitors to TERC.

IMG_3845Above:  Steve shows off an interchangeable camera stabilizer for his hexacopter (on the right).  The hexacopter can fly for up to 10 minutes on a charge and take breathtaking aerial 3D movies without putting life and limb in danger. (On the left, below Steve’s elbow, you can see the weighted underwater camera.)

Below:  Steve shows off cameras that are ideal for shooting 3D time lapses.
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Lake Viz Projects and Team Members in the News!

Wired Magazine Features the Shaping Watersheds Exhibit
Wired Magazine wrote a wonderful piece on our Shaping Watersheds exhibit, a.k.a. the AR Sandbox. It highlights what we think is the strength of the exhibit: the whimsical simplicity of playing with sand while layering complex, computational information on top of it. Although our visitors see cool topographic lines, bright colors, and water flow, the seamless integration between the sand, Kinect, computer, and projector makes this exhibit a tour de force of computational sophistication and an imaginative user interface. This Augmented-Reality Sandbox Turns Dirt Into a UI

New York Times Interviews Geoff Schladow
The New York Times interviewed our own Geoff Schladow for a piece that addressed the ongoing controversy between Nevada, California, environmentalists, and real estate developers. Since Tahoe straddles the state line, California and Nevada form a legal compact to mitigate human activity and development on the lake’s health. Nevada finds itself in a hard place as a lack of tourist dollars from the last economic downturn aren’t coming back as anticipated. Many feel that the new compact, a compromise between all parties, will impact Tahoe’s health negatively and could lead to over-development. Dr. Schladow focused on the lake’s health and provided the piece’s notable quote: “The lake is going to do what the lake is going to do,” Mr. Schladow said. “The water flows where the wind and the currents move it, and it doesn’t know about a state line.” A Balancing Act Around Lake Tahoe

Testing Tabletop Models for Lakes, Algae, and Plankton

Earlier this month we had a lot of fun testing a few of our hands-on tabletop activities. On the museum floor at the Lawrence Hall of Science, 70 people, ranging from elementary school-age children to adults, got a sneak preview of these new prototype activities and gave us their feedback to make them better. One of the tabletops we tested was the Seiche Wave Model. The model is a long, narrow tank that can be divided into sections for different colored water of different temperatures. Once the divider is removed, the different temperatures of water form layers, called thermoclines, based on density due to their temperature. By blowing air through straws, visitors saw how wind can make waves on a lake surface and also create internal waves, called seiche waves. Another favorite action children really enjoyed was pouring water through a tube to simulate how streams can produce seiche waves in a lake too.

Kids also liked playing the Algae and Plankton computer games. In this game, visitors learned how to identify different types of plankton and found out what kinds of phytoplankton zooplankton like to eat. Thanks to all the participants and their feedback, we know these activities are on the right track in nurturing curiosity and raising awareness about lakes and we’ve also gained some ideas on how to improve them.

-by Min Shih and edited by Maia Werner-Avidon