Hands-On History: Leeches Are Cute!

Never did I EVER think I would see a leech in real life. I mean, I know they exist and what they generally look like, but I never thought I would see one in the wild. Welp, I was wrong. AND, I saw not ONE but SEVERAL leeches. Before you think, "Where did Nathalie travel to THIS time?" I saw these leeches half a mile from where I work! In a neighborhood lake that we all have access to!

The lake down the street from our school

But let me back up and explain. Last summer, the Pontchartrain Conservancy, a Louisiana non-profit working to protect water in the southern part of our state, reached out to local schools looking for partner teachers for a project called FLOW, or Facilitating Learning in our Watershed. Since we would be discussing water as a general concept in my Hands-On History class, I thought it would be a good fit for us. And I know you might be thinking (as I was), "But Nathalie, what do YOU know about coastal science or water quality?" It's a fair question, but here's the thing: the nice people at the Conservancy train teachers to lead their students through the lessons. In December, I met with my trainers to practice water testing at a local lake, and I learned so much!

Scientists use several tests to determine the health of a body of water. They take the temperature of the water, test for pH levels, and look at turbidity (how murky the water is). Not surprisingly, these tests can help determine if the water is safe for creatures to live in. My students really enjoyed trying out all the specialized tools for these tests - yep, the Pontchartrain Conservancy supplies all the tools for your students to use. In testing for dissolved oxygen, they had to go through a bunch of steps to make the proper determination, and they really felt like scientists while doing it. But by far, their favorite activity in this unit was taking walking field trips to our neighborhood lake to dipnet for macroinvertebrates - the little critters that live in the water. Some of these cuties are more tolerant of pollution than others, and by identifying which cuties are present, one can tell how healthy the water is. 

Dipnetting requires the use of a net on a very long handle. One of my students immediately became the dipnetting expert. He dipnetted for everybody. He then dumped the net contents into our ready containers of lake water (so the cuties wouldn't be shocked by not being in the water). The students then used books and charts of macroinvertebrates to identify the cuties they had captured. We had gone through this process a couple of times to be ready for our co-teaching day with a member of the Conservancy team. We found lots of mosquito larvae and dragonfly nymphs. But nothing could prepare us for what we saw on that co-teaching!!! Leeches!!! The cutest tiger leeches you've ever seen! They were tiny because we think they were still babies, and they had stripes which helped us to determine that they were probably tiger leeches (...makes sense being so close to LSU. LOL) We were simply AMAZED that we had located leeches so close to human habitation. I was so dumb to think this!

A baby tiger leech near my pinkie finger

Leeches are actually pollution-tolerant creatures. They can put up with a lot, evidently, including thirty curious 8th graders and two nosey teachers disturbing their daily routine.

Possibly a dragonfly nymph

After all our testing, we determined that the lake near our school is pretty healthy. Could we drink it? No, and that led us to learning about the Southern Hills Aquifer, the source of drinking water in Baton Rouge. Most students think we get our water from the Mississippi River, but we don't. Using a lesson from my Roman Technology class that explores how the Romans used different sources of water for different purposes, we learned about the threat of salt-water intrusion into our fresh-water aquifer and how to bring awareness to this problem. We invited geologist Jesse Means from the Louisiana Department of Environmental Quality to visit us and demonstrate how aquifers work with his special model. My students enjoyed being the aquifer controllers.

We ended our study of water quality with a field trip to the nearby Center for Water Studies at LSU's Water Campus where we saw the GIANT interactive Mississippi River model, a mix of physical features and projection. If you teach science or social studies in Louisiana, you need to take your students to see this model. OMG. It was truly eye-opening to see how the river works to add and take away sediment, and how engineers are trying to correct some of the erosion and sinking of coastal lands that is taking place in Louisiana. Our field trip was sponsored by the Pontchartrain Conservancy as well.

We finished up our tour with a quick walk to the Mississippi River to see the old port near the Horace Wilkinson Bridge. It fun and educational to watch the huge barges and tugboats going by as well as the traffic on the bridge.

Our last lesson in this unit focused on Indigenous boats of Louisiana and a famous shipwreck off our state's coast. Our favorite archaeologists from the Louisiana Division of Archaeology came to visit! Josetta LeBoeuf and Karla Oesch talked about the now-famous Red River dugout canoe that will finally be displayed in National Wildlife Refuge in Bossier City. They also mentioned the cargo of a Spanish ship called the Nuevo Constante that was sunk by a hurricane near Lake Charles in 1766. They led the kids through a cool hands-on lesson about identifying the age of wood by the use of tree rings (dendrochronology).

This unit forced me to learn outside my comfort zone and teach some important material about the water that is around us all the time that we don't think nearly enough about. Even though I won't be teaching Hands-On History as a class next year, I plan to carry over many of these lessons into my Roman Technology classes during our aqueduct unit. Thanks to the Pontchartrain Conservancy for funding this work! We learned so much.