"Ignorance is Bliss": Really?

In my view of the world, science has a central role to play in resource management decisions. Scientific information, if obtained from well-designed studies, can serve as a foundation for such decisions, providing a description of the problem and of potential solutions. To be sure, scientific information is only part of the equation, and social, legal, and financial considerations are also critical to the development of sound management practices. Ideally, all of these information sources are used to develop proposed actions that are presented to the public and then amended as necessary. For this process to be effective, scientists and managers need to be clear about their intent and unbiased in their description of the problem and proposed solutions. Similarly, for public input to be useful the public must educate themselves on the issue. Problems in any of these areas can derail the process of developing sound decisions, and there are ample examples of such derailments. 

I've made a concerted effort to help members of the public educate themselves on the fish-frog issue (in part by writing this blog and maintaining the Mountain Yellow-legged Frog Web Site), and perhaps that is why I find it frustrating to see members of the public refusing to avail themselves of readily available information and instead advocating strongly-held opinions based only on hearsay. The recently released fish stocking EIR-EIS contains a summary of all comments submitted in response to the draft document (Appendix M), and one letter in particular provides a telling example of the dangers of being uninformed. This letter was submitted by the Backcountry Horsemen of California and it states (in part) that "there has been no conclusive scientific evidence to prove that frogs and fish cannot coexist", and that for mountain yellow-legged and Cascades frogs "it has not been determined beyond a shadow of a doubt the absolute specific cause of the decline". Based on this, the letter-writer argues for the "continued management and support of hatcheries to produce adequate number of fingerlings to accommodate the high levels of stocking to provide for high quality recreational fishing in all the high mountain lakes of the Sierras, Cascades and Klamath mountain ranges of California". 

Based on these comments, I'd be willing to bet that the letter-writer has not read a single one of the scientific papers that describe the impacts of introduced trout on amphibians in California's montane habitats. These studies were conducted by different research groups (including the California Department of Fish and Game) and include detailed surveys of amphibians and fish at more than 15,000 lakes and streams. The various studies are unanimous in their conclusion that trout introductions can cause negative impacts to mountain yellow-legged and Cascades frogs, and also demonstrate that trout removal can result in their rapid recovery. These studies have also clearly shown that the amphibian chytrid fungus is a major cause of the mountain yellow-legged frog's decline. Finally, these studies have identified pesticides as a possible additional cause of declines, although evidence in support of pesticides remains relatively weak (including my own paper on this topic). By any analysis, there is ample evidence that ongoing trout stocking has serious consequences for mountain yellow-legged and Cascades frogs. 

The letter-writer also ignores the evidence that the majority of mountain lakes in the Sierra Nevada (and elsewhere) actually harbor self-sustaining trout populations that would likely be negatively impacted by supplemental stocking of hatchery trout. So, in arguing that all mountain lakes in California be stocked with hatchery trout, the letter-writer is unwittingly arguing for policies that would decrease the quality of California's backcountry fisheries. That is hardly a reasonable position to advocate. 

To be productive partners in resolving the "fish-frog" debate, the public needs to make the effort to inform themselves. The best-available science on this issue isn't perfect, but it is by far the most detailed information source collected on the impacts of hatchery trout anywhere in the world. This literature provides a solid foundation for asking the critical questions that all of us interested in this issue should be asking. For example, given that angling is an important activity in California's mountain lakes but that fishless habitat is essential for several amphibian species, (1) what is the appropriate balance between fish and fishless habitat? Assuming that such a balance exists (and I believe that it does), (2) how should that distribution of fish and fishless habitats be achieved? Is a halt to the stocking of critical lakes sufficient? Should gill netting be employed to remove trout from critical habitats? If so, which ones? Should rotenone be used to remove trout from some entire basins? And (3) what role should fish stocking play in the management of California's montane lakes? Which lakes are self-sustaining and do not need to be stocked and which are which ones need to be stocked to maintain important fisheries?

Finding creative solutions to the fish-frog issue will require the informed, open-minded involvement of managers, scientists, and the public. Assertions that trout do not impact amphibians are not supported by the available evidence and hinder any attempts to find those solutions.


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