Dec 1, 2022 2 min read

HARRISBURG – The Pennsylvania Fish and Boat Commission announced that none of the water samples collected in Presque Isle Bay, Erie County, during October by the U.S. Fish and Wildlife Service contained environmental DNA of Silver Carp or Bighead Carp.

The tests were conducted at the request of the PFBC after the USFWS reported in July that Silver Carp eDNA had been detected in a single water sample collected in the bay last spring. The USFWS recommended waiting to conduct follow-up testing until fall 2022, when more favorable environmental conditions were present for eDNA sampling.

Upon learning of the positive detection in July, the PFBC took immediate precautionary measures by conducting targeted boat electrofishing sampling near the detection location. No Silver Carp were collected or observed.

The detection of eDNA is simply that – it indicates that DNA from the target organism is present in the sampling area, which doesn’t necessarily mean the organism itself is there. eDNA testing cannot distinguish DNA associated with a live fish from other DNA sources, such as bird feces, water transported in a recreational boat live well that had been in carp infested waters, or from melted ice used to store Silver Carp at fish markets that flowed into storm sewers.

However, repeated detections of eDNA over time increase concerns that the genetic material may have come from fish living in the area where the sample was collected, which is why regular eDNA sampling is recommended. The USFWS samples Presque Isle Bay annually in the spring and is planning to complete surveys again in May 2023.

Invasive carp, including Bighead Carp and Silver Carp, pose a significant threat to the Great Lakes ecosystem, the $7 billion-fishery, and other economic interests dependent on the Great Lakes and its tributaries. Bighead and Silver Carp compete with native and recreational fish species and are known to quickly reproduce.

Anglers are urged to become familiar with the identification of invasive carp, including both adults and juveniles, as the spread of juvenile invasive carp using live bait buckets has been identified as a potential point of entry into Great Lakes waters.