October 26, 2009

Fish Stocking EIR/EIS - Part 1

As stated in last week's blog post, the California Department of Fish and Game (CDFG) recently released their draft fish stocking EIR/EIS to the public. Comments are due on November 16. When the CDFG was ordered by the court to conduct this environmental analysis I had some hope that the CDFG would use this as an opportunity to fully evaluate their current stocking program and make changes that would benefit native wildlife (e.g., native amphibians and fish) and improve fisheries. Unfortunately, a read of the document's objectives statement indicates that this environmental analysis was largely an effort to justify the current fish stocking program. The objectives statement (page 5) reads, "The fundamental objectives of DFG’s Program are to continue the rearing and stocking of fish from its existing hatchery facilities for the recreational use of anglers, for mitigation of habitat loss attributable to dam construction and blocked access to upstream spawning areas, for mitigation of fish losses caused by operation of the state‐operated Sacramento–San Joaquin River Delta pumps, and for conservation and species restoration."

This objectives statement ignores abundant evidence that the stocking of trout and salmon can actually have negative effects on the resident fishery. For example, stocking of "catchable" trout into streams results in high levels of competition between stocked and resident trout. The end result is often a reduction in the total number of trout present. Similar problems beset stocking of salmon species. Given an abundance of these sorts of findings it is not at all clear that fish stocking is always the preferred means of providing recreational angling opportunities or that stocking can in fact mitigate for habitat loss caused by dams. As such the objectives statement in the EIR/EIS indicates the CDFGs interest in continuing the current stocking program regardless of whether some aspects of that program actually have negative effects on fisheries.

I would have liked to see an objectives statement such as the following: "To provide a stocking program that supports diverse anadromous and inland salmonid fisheries and protects native species and natural resources from adverse impacts from stocking." This statement makes it clear that fish stocking is a management tool that would be used when necessary to improve fisheries. I proposed this objectives statement to the CDFG some months ago but obviously my suggestion fell on deaf ears.

Given the flawed objectives statement upon which the EIR/EIS is based it is little surprise that the environmental analysis supports the continued fish stocking program with few meaningful changes. Next week I'll discuss the CDFGs flawed evaluation of fish stocking impacts.

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October 18, 2009

Another Field Season has Come and Gone

My 2009 summer field season ended in late September. Now weeks later all of the research gear is put away and the data is safely in my lakes database. The summer went largely as expected, with some notable successes and some unanticipated challenges. Below I've provided a summary of what our summer objectives were and what we actually accomplished. But first a sad note....

This summer I lost a close friend and fellow field biologist. On August 30, Jeff Maurer died in a climbing accident while ascending Third Pillar on Mt. Dana. Jeff had worked in Yosemite National Park since 1988, studying Peregrine Falcons, Great Gray Owls, and Northern Goshawks. In 2006 he took on the task of leading Yosemite's new lake restoration program, and in that capacity he directed fish removal efforts in numerous key locations around the Park. These efforts will continue, of course, but Jeff's infectious enthusiasm and unmatched dedication to this restoration effort will be sorely missed. He was truly one-of-a-kind. For stories about Jeff, check out http://yosemite-jeffmaurer.blogspot.com/.

So, what did we set out to do this summer? Our research team (me, Cherie Briggs, Vance Vredenburg, Erica Rosenblum, and more than a dozen field and laboratory assistants) had two primary objectives. The first objective follows from our field observations that after the arrival of the
amphibian chytrid fungus (Batrachochytrium dendrobatidis - "Bd") at a site most mountain yellow-legged frog populations decline to extinction but a few persist despite the disease, albeit at markedly lower densities. There are several potential explanations for these different disease outcomes, including inherent differences in frog susceptibility to chytridiomycosis (the disease caused by Bd) or differences between Bd strains in their virulence. So this summer we conducted a laboratory experiment to evaluate the relative roles of these two factors in driving different disease outcomes (frog population persistence versus extinction). We hope to wrap up the experiment by December.

Our second objective was to use a field experiment in which mountain yellow-legged frogs are cleared of Bd to determine whether this treatment influences the outcome of Bd epidemics. Frogs were treated with an anti-fungal drug at three lakes in each of two basins located in Kings Canyon National Park. Frog populations in both basins had suffered catastrophic declines in the past four years following the arrival of Bd, and without intervention it is likely that these frog populations would have been extinct within another couple of years. It will be 1-2 years before we have any definitive results but for now, suffice it to say that we were able to significantly reduce Bd loads on frogs in the field and this treatment dramatically improved frog survival. I'm hopeful that such frog treatments may provide us with an important conservation tool in the future, but we still have lots of unanswered questions that need to be addressed. I'll provide further updates as the results come in.

Finally, the California Dept. of Fish and Game (CDFG) released a draft fish stocking EIR/EIS to the public on September 25 (available from the CDFG web site). Comments on the draft document are due to the CDFG by November 16. Given that this document will guide CDFG fish stocking practices for many years I encourage everyone interested in this issue to read the EIR/EIS and provide comments to the CDFG. I'm still working my way through the 8 chapters and 12 appendices but it is clear that there is lots of room for improvement. I'll provide additional details on this document in upcoming blog posts. Stay tuned....

Now that I'm back behind my desk I'll be posting new Frog Blog entries every Monday morning. I hope you find them interesting and informative.

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