As a child, Dr. McBride used to visit the barrier islands off the coast of Georgia and he would wonder how the islands got there. He followed his curiosity through bachelor's, master's, and Ph.D programs. He is now a Coastal Geomorphologist. (Don't worry, I didn't know what it was either!) What he does is examine the coastal regions for changes in its geology. For instance, he was called in as a consultant to help with Exxon-Valdez oil spill clean up. More recently, he and a few other researchers formed hypotheses about the former existence of an inlet on the border of the Eastern Shore of Virginia and the Outer Banks of North Carolina. The current land forms indicated that there had been an inlet at that current location and geological radar confirmed the hypothesis. How cool is that?!
In the same presentation, we looked at a satellite map of the coast of Virginia, where the York and James rivers enter the Chesapeake Bay. Both of these rivers seem to make a swift bend northward to a specific point in the bay. Come to find out, they are moving toward a deep spot which was caused by... a meteor! Fun fact of the day!
Dr. Sklarew had 2 influential teachers and his parents that encouraged to pursue science as a career. He started off studying biological behavior of animals then moved into environmental science. He found his niche studying water and eventually began working for the United Nations and traveling the world researching water and water systems.
One study that Dr. Sklarew did was discovering what, if any, relationship the amount of CO2 emissions had with the amount of drinking water in various countries. What he found was surprising: there was a positive correlation. If the CO2 emissions went up, so did the amount of safe drinking water. He did not discover causation, but correlation. An interesting study, nonetheless!
After lunch we headed out to do a field study at the pond. The first thing I did was use a Secchi disk to discover the turbidity of the water. A Secchi Disk is a circle that is split by 2 perpendicular diameters. Diagonal quarters are the same color, either black or white. You lower the disk into the water until you cannot see it. Mark that point on the rope. Next, you raise the Secchi Disk until you reach the point where you can see it again. Take the 2 measurements and average them and that final number will give you the turbidity of the water.
Next, I got to use the kicknets. I couldn't wait to get into the stream and see what critters I could find! I put on the fabulous rubber boots and got right to work!
The kicknets do just what their name says; one person holds the net with the open end facing opposite the current and the other kicks the stream bottom and rustles up the sediment toward the net to attempt to get a sample of the organisms (primarily Macro-invertebrates) that live in that ecosystem. After multiple tries with the kicknets, Eric and I didn't come up with much in the way of Macro-invertebrates. So, we threw caution to the wind and just started lifting up rocks off of the stream bed. We found quite a few samples of algae, some clear jelly-like sacs that could have been egg sacs, a great deal of snails. And this is the kicker, quite literally! I had set the kicknet down so I could look underneath the rocks and when Eric grabbed it on the way out of the stream, we saw that we had caught a fish! Is that bad that it's the first fish I've ever caught? Yes, I've been fishing before!
Next I observed Dr. McBride taking a core sample of the sediment from the bottom of the pond. I'm kind of a geology nerd, so this was totally exciting! He took the core and then stratified it into manageable pieces so that we could more readily look for living things within the core:
Dr. McBride asked for a volunteer to look through the sample and my hand shot up as quickly as I possibly could without looking like... well... a 5th grader! :)
It was interesting to look through the sample. It was tough going, though. All of the sediment was clay. It was clumpy and dried very quickly and I had to continue to rehydrate the clay, And I made sure that I went through the layers with tweezers, just in case I found something. I did find 2 very small worms in the uppermost portion. They curled themselves up in a ball when I discovered them, but once I returned them to a water environment, they uncurled themselves and were about an inch and a half long each!
The first layer was the only layer that I found living organisms. I found organic matter in the subsequent layers, but as I learned later, the oxygen levels in the core sample probably weren't high enough to support life. When the sediment turns a greenish color (it looks like copper that's been exposed to the elements; like the statue of liberty), the oxygen levels are low.
Next, we were able to take a look at the dissolved oxygen levels, the temperature, and the conductivity of the pond.
If you look in the bucket, that cylinder holds all of the probes that take all of the afore mentioned measurements. It is attached to the meter that Dr. Sklarew is holding in his hand in the picture. One person drops the meter into the water while another reads off the measurements, while still another records the measurements. The meter is very sensitive, so as the one who was reading off the measurements, it was very difficult! The numbers never stayed exactly the same, so what I saw in one small second was what was recorded.
The most interesting number was the dissolved oxygen level. 100% O2 level is baseline. If the number is greater than 100%, then that indicates that plant life is in overdrive, as O2 is a product of respiration for plants. If the O2 level is below 100%, that means that animal life is populating the area and absorbing the oxygen that the plants are giving off.
Another interesting number was the conductivity measurement. This number is an indicator of how much salt is in the water. This number can tell whether the water is fresh, brackish, or salty. Of course the pond was considered freshwater, but it was still very cool to see the numbers back it up!
What a great day! I learned so much! If I'm having this much fun, imagine what my students will feel! Tomorrow... out on the boat! :)
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