HAMMONDSPORT, NY – The girls in Hammonsport Brownie Troupe 41002 will earn their “World of Water” badge for the work they did this week on Lamoka Lake. The Brownies and their troupe leaders focused specifically on examining the small feeder tributary running into Keuka Lake at Champlain Beach. For about three hours, the troupe focused on collecting data that will be used to assess the health of the aquatic ecosystem in the tributary.
The Learning & Collection
9:15 am, the troupe arrived at the park at Champlain Beach and gathered around a picnic table for an introduction by Rich Hurley. It was a fifteen-minute crash course on biotic indexing. Hurley explained what macroinvertebrates were and showed pictures to the girls on the identification chart. They learned that some of these small animals were more resistant to pollution and poor water conditions than others. They understood that some of the macroinvertebrates were more sensitive to pollution and finding them in the ecosystem would indicate a healthy ecosystem.
The small tributary or “feeder creek” that emptied into the lake was chosen as a the area for research. The Brownies and their troupe leaders took to the stream with dip nets, trying to gather up as many of the small bugs as they could find. They spent about 40 minutes in the water learning how to capture the, sometime difficult-to-find, macroinvertebrates. The girls quickly learned that teamwork would be essential to their success. A simple swoop of the nets through the water didn’t yield many result.
By working in pairs, one girl could lift the under-water rocks and create a disturbance, while another girl held a net, just downstream to collect everything that was dislodged. Others held nets from a small bridge as troupe leaders kicked up silt and rocks.
As the young Brownies started to fill their nets with rocks, dirt, plant material, and macroinvertebrate specimens, they would return them to a nearby park table for sorting, before returning to the stream for another shot at collection.
As the dip nets returned to the table, they were emptied into large plastic tubs of stream water. Troupe leaders sifted through the tubs with magnifying lenses and eye droppers, removing any small bit of animal life they could find and transferring it to petri dishes to be counted. Though some of the small invertebrates were easy to spot, others were small and not immediately found. In many cases, the keen eyes of the younger girls were more effective at spotting the a slight movement or wiggle of a hidden specimen the tub.
The petri dishes with collected specimens filled up. Some girls continued searching the tubs for more specimens while others moved into a new group and worked with Hurley and troupe leaders to start the identification process. One-by-one the girls and leaders examined the small animals and searched for them on the identification chart. Some of the identifications were more difficult and required closer examination. With each positive identification, Hurley spoke with the girls about it’s biotic value and had them record a tally mark on the final record.
There were a total of XXX specimens collected and tallied. Using the method developed by Dr. Robert Bode and used by the NYS Dept. of Environmental Conservation, Hurley calculated a a biotic value of 60.73. The DEC considers that to be in the “fair” range.
“Their attention span went longer than expected, so we went into overtime,” Hurley said. “Instead of just collecting insects, we did some other evaluations.”
Most popular, with the girls, was the transparency tube. After a bit more instruction, the Brownies, collected water from the stream and slowly started pouring it into the tube. Transparency measure how clear the water it. Marked at the bottom of the long tube, was a black X. They poured water into the tube and took turns looking looking down the tube at the black X. If they could still see it, after adding the water, they would add more. Once they agreed that the X was no longer visible, they recorded the measurement of water that was needed to make the X dissapear.
The group finished up the day by collecting water surface tension data. Each of them were given a penny and an eye-dropper. With water collected from the stream in the eye droppers, the girls added one drop at a time to the top of the penny. Surface tension causes the water to bead up and stay on top of the penny without running off. Like a stressful game of Jenga, the Brownies carefully added water to the penny, counting the number of drops, until the surface tension broke and the water spilled over the edge of the penny.
The Brownie Troupe finished at noon, with parents returning to pick kids up.
Data collected by Troupe 41002 was catalogued and submitted to the New York State Department of Environmental Conservation.
The biotic index collected a total odd XXX specimens (more than needed for the survey). Most of the macroinvertebrates ranged on the lower/mid range with biotic values around 4 and 5. A final biotic value of 60.73 was calculated from the collected data. According to the Bode method, the score give the feeder creek a “fair” rating.
The transparency was observed to be about 93cm. This means that the big X, at the bottom of the tube, disappeared from vision under approx. 93cm of water from the stream.
The surface tension test required an average ~23 drops before of water before running off the penny.
Special thanks to Brownie Troop 41002: Lexy Wilson, Delaney Ollis, Sarah Lyle, Makenzie Anderson, and Brownie troop leaders Katherine Peterson-Lyle, and Ellie Crouch. Congratulations on your “World of Water” Badge.