Black fly pupa found at Goose Creek.
Photo by Amy Ulland
Newly emerged Virginia Bluebells lined the trail to the bank of the Goose Creek where Stream Team volunteers conducted a benthic macroinvertebrate survey on March 19. The team consisted of Friends of Confluence Park members Jack McNamee and Harrison Crecraft, Riverside High School Environmental Club sponsor Lisa Klug and sophomore Audrey Bowling, and Stream Team Coordinator Amy Ulland.
Three collection nets yielded a wide variety of macros, including pollution-sensitive stoneflies, mayflies, and hellgrammites, as well as pollution-tolerant worms and midges. The team also observed quite a few emerging adult midges and a black fly pupa.
The hair-like extensions from the top of the black fly pupa are actually gills, used to absorb dissolved oxygen from the water. The pupa is encased in a silk cocoon attached to vegetation for other objects in the stream. The adult fly emerges from this case through a slit and floats to the surface of the water on an air bubble.
The stream received a score of 7 out of 12 indicating unacceptable ecological conditions. You can see all stream scores for the Goose Creek site on the site page.
Participants look for macros.
Photo by Amy Ulland