Is PFBC still conducting surveys on Big Spring to keep tabs on the biomass of brook vs rainbow post-restoration? They did for a few years and it was showing a shift in favor of brook trout but I haven't seen anything recently.
The last survey was in 2016 (as far as I'm aware) and a report was produced for the 2017 wild trout summit.
Page 285
Since 1974, a Conference for Concerned Biologists, Fisheries Managers, and Anglers
www.wildtroutsymposium.com
A few key points:
In the western United States, angler preference among salmonids may be minor or nonexistent and evidence suggests that many anglers prefer nonnative salmonids over natives due to their perceived superior sporting qualities (i.e. fighting ability, jumping ability, etc.) and their larger maximum length (Quist and Hubert 2004).
Of course, many anglers prefer nonnative salmonids. If that's how we're determining what to do, then we'll eradicate brook trout from the state. Conservation of the species shouldn't be bound by angler want.
The economic issues associated with Brook Trout restoration are directly related to the previously described social issue regarding preference of some anglers for nonnative salmonids. In the western United States, Quist and Hubert (2004) asserted that the net economic benefit linked to replacement of Cutthroat Trout Oncorhynchus clarkii by nonnative salmonids depended on the values society attributed to a particular species, and this concept is likely applicable to native species management in Pennsylvania as well. Nonnative salmonids are likely to be considered ecological and social surrogates for natives in most cases (Quist and Hubert 2004), thus their presence is likely to result in no net economic change to the value of the fishery.
They don't generate enough money, so we'll sacrifice them to appease anglers because money is more important than ecosystem health or the long-term security of the species.
Furthermore, removal through either active or passive means would likely be ineffective, costly, and opposed by the public.
Multiple removal electrofishing costs approximately $8,826 per stream km. Public support for reclamation projects is largely positive when the public is informed and educated about the purpose.
Based on the ecology of sympatric Brook Trout and Rainbow Trout populations, some reduction of Rainbow Trout will likely be necessary to meet agency objectives.
Rainbow trout aren't simply surrogates for native brook trout. Interspecies interactions have impacts that we don't fully understand. i.e., larval hellbender electro-chemical response to native predator fishes compared to nonnative salmonids.
The authors demonstrated competition between juvenile (age-0) rainbow trout and brook trout in a raceway environment:
juvenile brook trout grew faster in allopatry than in sympatry with rainbow trout. Potential brook trout responses to rainbow trout include a decrease in the survival rate of small fish, a change in density dependence in the survival of small fish, and a decrease in growth rates of all sizes.
There are impacts on the species by the mere presence of nonnative fish.
The authors compared management strategies for controlling rainbow trout to promote native brook trout conservation. They concluded that habitat alteration and angler harvest were less effective than electrofishing removal.
Speaking of cost, the current approach seems to be to try to alter the habitat to favor brook trout. That assumes that habitat preference could overcome the negative effects of sympatry. So you could do a few electrofishing removal efforts and be done, or you could conduct years of habitat manipulation that may or may not result in the desired species biomass changes. Which is more costly?
We won't even implement admittedly less than optimal angling regulations that have absolutely zero cost impact. Apparently, given what we know, we've chosen the most expensive and least effective model to manage for brook trout (habitat alteration).
https://doi.org/10.1577/1548-8659(1983)3%3C72:SCOBTC%3E2.0.CO;2
This study empirically demonstrated increased brook trout biomass and abundance in response to experimentally reduced numbers of non-native rainbow trout over 4 years. The authors discuss the potential of backpack electrofishing for the removal of non-native trout as a management strategy for native brook trout.
The authors reviewed evidence that introduced rainbow trout have reduced native brook trout abundance and distribution in the southern Appalachian mountains, focusing on Great Smoky Mountains National Park.
Back to the Big Spring report from the wild trout symposium:
Likewise, in 2012, agency biologists proposed a selective harvest regulation that would continue to restrict gear to fly-fishing tackle, but permit the harvest of Rainbow Trout and Brown Trout while no-harvest regulations for Brook Trout would remain in effect. This regulation was crafted to provide fly-fishing anglers the opportunity to harvest fish and further aide in maintaining and promoting a wild trout community dominated by Brook Trout; however, the proposal was met with strong public opposition and subsequently not implemented.
When NPS reclaims streams in GSMNP, they don't ask the public for permission. They do what's best for the resource and then explain to the public why they did it, or they solicit feedback, but obviously, ultimately carry out the reclamation. If the proposed changes at Big Spring were met with "strong public opposition" (I'd like to know exactly what this opposition was) then PFBC did a poor job of explaining the purpose of the changes. Either that or the people of South Carolina and Tennessee have a far better grasp on the importance of native species than the people of Pennsylvania.
This situation illustrates the importance of the value society may place on nonnative fisheries. To effectively advocate for native species management efforts such as those described here, biologists must bridge the gap among science, societal values, and economics so that anglers and policy makers can make informed decisions regarding native species conservation techniques such as selective harvest of nonnative species.
This is absolutely correct, but it has to come from the agency. Reluctance to even mention brook trout on social media, relentlessly posting nonnative stocked trout photos on Facebook, failing to implement a single brook trout specific angling regulation anywhere in the state, continuing to stock nonnative trout over brook trout, shunning people who want to help with this messaging, and failing to promote native species in general certainly doesn't seem like the path to what's stated here.
