Benthic
Benthic refers to the organisms that live in, or attach themselves to the bottom of a river or creek. Most benthic organisms are aquatic insects or the aquatic stages of life. In Environmental Statistics, it was essential to see what kinds of organisms live in the streams we test. In order to catch these organisms, a student would stand in an area with lots of rocks, with a net. While one student holds the net another stands upstream and kicks up as many rocks as they can, to get things to flow downstream into the net. As the rocks are kicked around, the organisms that are stuck to them fall off and float downstream. After moving the rocks for a few minutes, the net is carefully pulled out of the water and taken over to a table covered with a sheet. Once the net is on the table, two or three students stand around with tweezers, looking for squirming bugs. If an organism is spotted, it is picked up, and placed into a container. If students are having trouble seeing organisms, they can use spray bottles to squirt them. Squirting the aquatic insects with water causes them to move around, making them much easier to find. After all the organisms in a sample have been captured and identified, we determine the total number of each type of benthic organism captured. A good benthic sample is more than 100 organisms, as well as a lot of diversity in the types of organisms. If less than 100 are found in the first sample, then the process is repeated, to ensure that 100 organisms are found. Adjustments made this year were
1. We labeled the ice tray compartment with organism names. When separated the specimens we identified them and placed them into the labeled compartments. This made the final count more accurate and efficient.
2. We marked the sheet that was placed under the net into grids. This enabled us to assign grids for counting midges and organisms that slipped through the mesh of the net.
Again, a more accurate and efficient count was possible. Testing the benthic of the streams is essential for our data study. Having organisms like Water Pennies and Caddisflies let us know that the streams are healthy. Benthic samples show the diversity and abundance of different organisms in the water. The benthic also tells us what kinds of organisms live in the stream with the mussels. In order to eventually transfer the mussels into a new stream, the stream has to have the proper type of organisms to coexist with the mussel. Without testing the benthic we would have no way to know if the new stream would be safe to move the mussels into.