by John Lavaccare, Communications Intern, Nine Mile Run Watershed Association
Earlier this month I spent the day on an electrofishing trip through the Nine Mile Run stream led by two instructors from Duquesne University, Dr. Brady Porter and Dr. Beth Dakin. Electrofishing is an activity where scientists use an electric pole to temporarily stun fish, catalog the species and sizes of fish found, then release the fish back into the water. Electrofishing helps us understand the quality and health of the Nine Mile Run stream by learning more about the variety of fish that live in the stream.
Along with Dr. Porter and Dr. Dakin, there were 7 students on the trip from Duquesne University, Chatham University, and the University of Pittsburgh. The students included undergraduates, graduate students, and a postgraduate student. Some were there as part of a class assignment; Dr. Dakin said the assignment helps students understand “the amount of effort that lets us know things about ecosystems and fish communities”.
Others were there because they simply wanted to take part in the electrofishing activities. The students had various interests and knowledge levels about marine biology and ecology, and it seemed like everyone had an enjoyable and enriching experience.
One local community member joined us on the trip: Mike Koryak, a former member of the U.S. Army Corps of Engineers who retired in 2004, and has served on the NMR Monitoring Committee since 2006. Mike said he was part of the original inspection project at this site, and he marveled at the progress the stream has made since the restoration project was completed in 2006.
“In so many ways, it’s been dramatic,” Mike said of NMR’s transformation. “It’s a long time coming.”
We started our electrofishing day in the lower part of the Nine Mile Run stream, near where it meets the Monongahela River. The process goes something like this: The person with the electric rod has a charge emanating from both the front of their pole and from a “rat tail” that hangs from the box on their back. While this is happening, participants with nets examine the areas where the electric rod and rat tail have been, collecting the stunned fish from the water and putting them in buckets to be sorted and counted later. If the stream is still electrified (which it is briefly after the rod has passed through it), they have to be careful not to get the exposed skin on their hands in the water. In addition, electrofishing participants wear waders, which are akin to rubber overalls connected to boots. They help protect the participants’ legs from water and from electrocution, so any holes in them could prove troublesome.
This first part of the process involved separating fish by species into buckets. Artificial bubbles were used to keep the water in the buckets oxygenated. In all, 11 species were catalogued during the first portion of the electrofishing process. Dr. Porter and Dr. Dakin were able to classify the fish on sight based on their spots, mouth placement, eyes, and other features. Cullen Hanes, an electrofishing participant and undergraduate student at Chatham who is interested in herpetology, or the study of amphibians, said he hopes to be able to identify amphibians in the way Dr. Porter can identify fish. “I tried to listen to him as best I could,” Cullen said. “I still, like, had to keep asking what type of fish this is.”
After the fish were sorted successfully, they needed to be counted, measured, and weighed before being released. In the first part of the stream, spotfin shiners (like the one above) were abundant, and the electrofishing team counted 199 of them in this portion of the stream. After the event, Dr. Porter said that spotfin shiners are a “pioneering species”, which means that it’s one of the first types of fish to break into more polluted areas. He said surveys like this one allow scientists to understand which species are pioneers.
This rainbow darter was found in the upper part of the NMR stream area we surveyed.
Though we were most interested in the fish, there were various other types of wildlife to be found about the stream, including two caterpillars like this, a crawfish, and even a bullfrog.
In all, Mike and Dr. Porter felt that this survey found fewer fish in the stream than in past years. They theorized that this might be because of the construction for the new bridge to the Duck Hollow neighborhood, which has caused the stream to be culverted underneath a gravel bridge in the middle of the area we surveyed. Dr. Porter theorized that transient species—those that come into the Nine Mile Run stream through the Monongahela River—are having difficulties making their way through the culverts to the upper part of the stream. Nine Mile Run Watershed Association has been and will continue to monitor the effects of this construction project.