Pennsylvania’s Position on AIS

The Pennsylvania Fish and Boat Commission recently published a position statement on non-native aquatic species. You can find their position statement here: https://www.pa.gov/content/dam/copapwp-pagov/en/fishandboat/documents/conservation/ais/pfbc-nonnativeposition.pdf

Frankly, I’m surprised they went to the lengths of writing and publishing this document, and I wanted to dissect it a bit here and point out a few issues. First a little background from my perspective. As I’ve pointed out throughout this site, Pennsylvania has a long history of stocking nonnative fish. Two posts that would be a good read before reading this one are The Neverending Cycle and NATIVE. Both articles explore how Pennsylvania got its start in the fish stocking business, and the difference between native fish and nonnative fish, and their impacts on each other. I have long held the belief that the nonnative sportfish in this state, protected by angling regulations and beloved by many, are, in fact, invasive species. Another article on this site that touches on this subject is Invasives.

Let’s dive into dissecting the Bureau of Fisheries statement on nonnative aquatic species. In the opening paragraph, they give a very abbreviated history of the stocking of nonnative species for food and sport to “replenish fish stocks.” They note that many water bodies in the commonwealth were impaired during this period, presumably due to industrial waste and deforestation. They mention the use of Common Carp and brown trout as examples of nonnative species that were deliberately introduced into commonwealth waters. They also touch on species native to the state’s borders that have spread into watersheds they weren’t historically native to, such as Smallmouth Bass, Flathead Catfish, Blue Catfish, and others.

The second paragraph covers the fact that the PFBC has jurisdiction over all the aquatic animals within the state, native, nonnative, and invasive. Here, they used their own definition of AIS to describe them as: “non-native aquatic organisms that could establish reproducing populations and cause ecological harm, economic harm, and/or harm to human health when introduced outside of their native range.” It’s worth pointing out here that the definition of invasive species is; “non-native organism that causes economic or environmental harm, or harm to human health, after being introduced to a new ecosystem.” While the two are similar, there is an important addition to the PFBC definition, which I believe is important. The use of “could establish reproducing populations” implies that they’re focused on new speices that might be introduced from here out. They more or less establish a clause here that starts to alleviate the issue of established nonnative species.

In the third paragraph, they’ll expand on this idea that they’re only really concerned with “new” AIS. They cover a broad range of approaches to addressing AIS, including education, outreach, monitoring, early-detection surveys, rapid response, coordination, and enforcement of regulations related to AIS and the introduction or transport of aquatic organisms in the Commonwealth. Here, again, they explicitely say, “PFBC focuses AIS management efforts on more recently introduced non-native species that are not well-established statewide.”

The fourth paragraph mentions that PFBC manages the importation, possession, transportation, propagation, and/or introduction of fish and other aquatic organisms in the Commonwealth’s waters. Essentially, PFBC oversees permits for aquaculture, importation, and stocking. It’s worth pointing out here that until 2024, Pennsylvania had no requirements for private stocking in the Commonwealth’s waters. A person could go to a fish hatchery, buy fish, and stock them anywhere they wanted without telling anyone. In 2024, PFBC passed regulations that require private citizens to file a “Notice of Stocking” form with PFBC so that they are at least aware of what species are being put in what waters. It’s worth noting here that the original intent was a “Stocking Authorization” form, which would require private citizens to seek approval or authorization PRIOR to stocking. After the aquaculture lobby in Pennsylvania got involved, PFBC backed off the “authorization” approach and turned it into a simple report of what was already done.

The last paragraph is where I have most of my concerns/issues. Here, they say, “In most instances, non-native species stocked as part of ongoing management activities currently exhibit little to no natural reproduction, exist in watersheds containing naturalized populations, or are stocked in waters that have been altered by human activity and no longer support the historic stream fish community.” I’ve personally witnessed these fish reproducing in the wild. In some cases, they’re being stocked in waters that support Class A populations, either where they’re stocked or just upstream from where they’re stocked. It’s very important to note that these nonnative fish that “exhibit little to no natural reproduction” are fully capable of natural reproduction. They are not triploid (sterile) fish, and while they’re reared in raceways originating from a long line of captive bred fish bred to grow fast and be resistent to hatchery born illnesses, they’re animals with the ability to reproduce in the wild. To quote Dr. Malcolm…

The single line in the entire document that I take the most issue with is this one, “Additionally, the PFBC will manage for the benefit of native species in instances where practical.” Cleverly, they use “where practical” as a qualifier here, and I guess you could bend all kinds of situations into impractical ones. I’ll focus on one stream that I like to use as an example, though. Big Spring. I’ve written about Big Spring throughout this site as it’s usually a pretty good example of how badly a state can manage for a native species. A really quick primer on Big Spring to set the stage is that the stream was known worldwide for its brook trout population and angling. At some point, it was dammed multiple times for mills, then a fish farm/hatchery, then the state put a fish hatchery on its spring source, which pretty much completely killed the stream. The state then realized how bad the hatchery was (due to pressure from private citizens) and they tore the hatchery out. The stream has bounced back, but there is a very persistent population of brown and rainbow trout. In the early 2000s, PFBC scoped making angling regulations that would protect brook trout while allowing the harvest of nonantive species, but backed off due to “public outcry” (which was basically a small vocal group of people who should have been in full support of the proposal) and most recently PFBC has tried to modify the habitat within the stream to favor brook trout over the nonnative species, which is arguably impossible as brook, brown and rainbow trout all have very similar habitat and spawning preferences.

Suppose one of the approaches of the PFBC is to manage for native species preferentially. Why wouldn’t they enact angling regulations that allow the harvest of nonnative species on Big Spring? Big Spring is a “closed system” because it has a large impassable barrier at its lower end that prevents aquatic species from entering the stream from the receiving river. In theory, if brown and rainbow trout were removed from Big Spring, they couldn’t get back in unless deliberately stocked by bucket biologists or out of spite. In theory, if PFBC were more forthcoming about the importance of native species and not spreading nonnative species all over the state, we wouldn’t have bucket biologists and angry nonnative fish lovers.

To date, in late 2025, Pennsylvania still has zero angling regulations to protect brook trout by species. If PFBC is managing to benefit native species, why haven’t they put in place an angling regulation that protects brook trout where they exist with other nonnative trout species? Ironically, PFBC recently enacted angling regulations to protect brown trout where rainbow trout are stocked. If that’s not proof enough that the whole “managing to benefit native species” is nothing more than lip service, I don’t know what is.

This whole issue is fascinating to watch unfold. For decades, PFBC has been rearing and stocking invasive species. Brown and Rainbow trout are responsible for the loss of brook trout and likely countless other native aquatic and even terrestrial species in the Commonwealth. While they claim to be monitoring, I don’t believe anyone has looked at the impact of nonnative salmonids on native non-game species. As I mentioned in NATIVE, research from New Zealand shows that the presence of brown trout impacts ecosystem function down to the algal level. Likely, brown trout have negatively impacted the entire ecosystem in Pennsylvania as well.

Now, PFBC is dealing with new AIS like round gobies, mudsnails, and others while trying to educate the public on the dangers of introduced nonnative species. It’s entirely reasonable and logical for the public to start to question why these salmonids get a pass. In reality, they shouldn’t, but we’ve built quite a system of trout aquaculture and angling culture in this state, and to break that chain is quite tricky.