Fish kill investigations are a race against the clock and conditions

​​Looking closer at “20 dead carp and suckers” along the banks of the Frankstown Branch of the Juniata River on Friday, Aug. 28, John Coxey couldn’t get past the unexpected odor.

“It was like that grease used at amusement parks, only much more pungent,” he said.

While he only witnessed dead carp in person, other affected species have been mentioned on social media, he added.

“I did see some dead stocked rainbows in some of the pictures,” Coxey said. “There were some dead crayfish and freshwater mussels in the pictures, as well.”

The impacted section of the Frankstown Branch holds wild brown trout, he added, when water temperatures allow.

“I am hoping the trout already migrated into the tributaries before the event occurred,” he said.

Investigating a fish kill event such as this can be very difficult, admitted John Repetz, community relations coordinator for the Department of Environmental Protection.

“The biggest factor is time – the length of time between the actual event, when it is discovered, when it is reported and when it is investigated. Flow and mixing in stream can quickly disperse or dilute the pollutants that caused the fish kill,” he said. “Evidence can quickly be pushed downstream and fish decomposition occurs quickly.”

Heather Smiles, chief the Pennsylvania Fish and Boat Commission’s Division of Environmental Services, agreed.

“The evidence practically disappears right in front of us,” she said. “Not all dead fish float right away, and predators can get to them quickly. There was a snail kill in a lake earlier this summer that ended up being an aquatic herbicide situation that went bad. It was so hard to count that and figure out how bad it was because overnight, so many were eaten up by various critters.”

Fish kill events can also be caused by a wide variety of factors, which can add to the difficulty in determining  a cause, Pennsylvania Fish and Boat Commission Communications Director Mike Parker admitted.

“Pollution is one cause, where a foreign substance such as a petroleum product, municipal waste, salt or agricultural chemical enters a waterway in enough concentration that it directly impacts the fish, reptiles and/or amphibians,” he said. “Thermal changes, or changes in water temperature, can be both natural and manmade, such as when warm water is discharged from a power plant or other industrial facility.”

Fish kills can also be common following spawning activity, which is stressful for the fish, he added.

“It does not take much for a weakened fish post-spawn to succumb to changing environmental conditions or even a small pollution event that might not otherwise result in mortality,” Parker said.

“Also, the presence of aquatic grasses and other vegetation in a water body can contribute to fish kills, as those plants can cause oxygen depletion in the water. Fish are generally able to retreat to areas with better oxygen, but especially in lakes and ponds during a streak of hot weather, these conditions can occur very quickly and the fish perish.”

Fish kill reports can be very inconsistent, Parker added.

“Sometimes, they are never reported, while others -- even small natural events -- receive a lot of attention, depending on the waterway and the species of fish,” he said. “In other words, most people won’t pick up the phone when they see a few dead bluegills, but they will be very concerned when they see a wild trout turning up dead on the streambank.”

Upon first responding to a fish kill report, DEP investigators attempt to gain background information, ask basic questions and make initial observations.

“When? Where? Are the fish distressed or dead … or both? Is there an obvious source? Are there any noticeable colors, odors or cloudiness of the water?” Repetz said. “What is upstream from this location? What is the time of the year? What are the air and water temperatures?”

If just one species of fish is involved, Repetz added, it could be an indicator of something that is more likely a natural cause, where a wider variety of species can indicate that pollution is involved.

Water tests may be conducted immediately in the field looking at pH values, dissolved oxygen levels, total residual chlorine and temperature.

“If a specific contaminant or source is suspected, a laboratory sample may be taken,” Repetz said, adding that certain fish kills are caused by a one-time discharge of pollutants, especially in certain regions.

“These could include manure runoff, sewage from a line break, chlorine from a waterline break or repair work, spill or dumping of industrial chemicals and power plant discharges that cause rapid temperature changes in the water.”

Noting the affected species can also help pinpoint a cause, Smiles added.

“Carp are mostly bottom feeders, and they are pretty hardy, so typically it takes something heavier than water and pretty strong to impact them,” she said. “Trout, on the other hand, can be pretty sensitive to various changes, including those connected to aquatic herbicides and certain compounds, like copper.”

So what caused the fish kill situation recently within the greater Juniata River?

“The fish in the Frankstown Branch had been dead for quite a while and were decomposing, making it more difficult to determine a cause,” Repetz said. “The DEP is continuing to investigate.”

Meanwhile, Coxey has his own own theory, suggesting it is related to a nearby paper mill that is allegedly connected to hot tannic-laden effluent -- causing brown and purple river water with the foul smell he experienced on Aug. 28 -- along with possibly some ammonia used for chemical spill cleanup winding up in the waterway.

Parker admitted that if the fish kill was caused by a pollution event, the DEP and Fish and Boat Commission will identify and track down those involved.

“When there is a confirmed pollution event, the DEP coordinates the cleanup and deals with the violator related to water quality,” he said, adding that the Fish and Boat Commission assists with certain parts of the process. “We can file charges against the violator, though most cases end in a settlement in which any monies collected go toward restoring the resource in the affected waterway.”

If you come across a potential fish kill situation, it can be reported via the DEP website (www.dep.pa.gov) by clicking “Report an Incident” and follow up by contacting the appropriate regional office (broken down into six region: North-central, northeast, southeast, south-central, southwest and northwest.)

Fish kill situations can also be reported to the Fish and Boat Commission by calling 855-FISH-KIL (855-347-4545).

Photos from
​the Frankstown 

The following are some images from the Frankstown Branch of the Juniata River as shared on social media by John Coxey and Maranda Orr.