Author: Dennis D. Murphy

The mystifying absence of hypothesis testing in the Delta science endeavor

Just about every one of us was introduced to the scientific method in a middle-school science class. We were told that science happens when hypotheses about how things work are evaluated using observations and data. Facts we were told emerge when hypotheses stand up or don’t stand up to that test. And that we learned is how science is done  Of course, for the very most of us that straightforward explanation had no ready adolescent application, and the lesson like so many others was lost in the white noise of stuff that mattered at the time. Now, even for the teenagers who were later to become scientists, that early in-one-ear-and-out-the-other […]
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Adaptive resource management in the Delta and Bay – it’s proving to be an elusive imperative

Adaptive resource management is widely acknowledged as the de rigueur approach to the management of natural resources. It is a form of structured decision-making that facilitates use of the best available scientific information by resource managers, and it draws approval from the involvement of stakeholders in its design and implementation. So, when the Delta Reform Act of 2009 identified adaptive management as the format and approach to resource management, the State of California showed a commitment to ensuring that the best professional standards of resource-management practice would be used to address the damaged ecosystems and imperiled species in the Sacramento-San Joaquin Delta and adjacent San Francisco Bay.  The Act is anchored by […]
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California’s resources agencies and the delta smelt’s slide toward extinction

Even that fraction of the public that is the least interested in California’s environmental health likely has heard of the delta smelt — the imperiled fish of the upper San Francisco Estuary. The diminutive fish that’s launched way more than its share of controversy. The fish that appears to be inching closer to extinction by the month.  To be sure, the delta smelt’s numbers are in decline. And the apparent causes are many. The most abundant fishes in the Delta are non-native species that both compete with and prey upon the delta smelt. Contaminants known and unknown poison its waters. Summer-time water temperatures, increasing in real time with climate change, […]
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Delta smelt monitoring malpractice – a disaster for the fish, impactful to California’s economy

Monitoring serves two essential purposes when it comes to fish and wildlife conservation. First, it informs our understanding of the status and trend of populations that we want to conserve and recover. Second, it informs the design and implementation of conservation measures to benefit those populations and allows resource managers to assess the effectiveness of such measures.  Absent monitoring, we are guided by intuition, surmise, or plain faith in determining whether we should intervene to protect a species and how we should go about doing so. While delta smelt have been protected under the California and federal Endangered Species Acts for almost three decades and federal and state regulatory agencies have […]
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Resource managers should consider the law of “limiting factors” if they have any hope of saving the imperiled delta smelt

It’s not lost on those concerned with the environmental health of the Sacramento-San Joaquin Delta and adjacent upper San Francisco Estuary that efforts to reverse declines of its imperiled fishes are failing. All the region’s fishes that are protected under the federal Endangered Species Act appear to have suffered reductions, some dramatic reductions, in abundance over the past two decades. The failure to respond to a native fishery in crisis falls in substantive part on the collective shoulders of the well-funded scientific community. From long-term surveys incapable of accurately monitoring the status and trends in numbers of those imperiled fishes to laboratory studies that can’t possibly mimic in-situ estuary conditions, […]
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Whither habitat for the imperiled delta smelt?

Conservation science has offered one widely appreciated truism above all others. Habitat loss and fragmentation is the primary cause of imperilment and extinction for very many species. This is certainly the case for the delta smelt, which has seen its habitat diminished and transformed by human activities dating back to California’s gold rush era. Congress recognized the importance of habitat when it enacted the federal Endangered Species Act nearly five decades ago, declaring as its purpose — “to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved” — in other words, to protect and restore the habitats that support imperiled species. The […]
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A new understanding of the status of longfin smelt and its conservation needs

Late last year the State Water Contractors hosted a first-ever Longfin Smelt Science Symposium on in Sacramento. The meeting featured and was attended by all researchers with first-hand and on-the-water experiences with the species in a forum that addressed both its ecology and genetics. Information emerged that has direct and immediate application in the conservation of the fish. The longfin smelt was listed as threatened by the State of California in 2009. The then Department of Fish and Game in its status review of the species, noted spare survey data and anecdotal records of the species across its coastal range from Alaska to just south of San Francisco Bay. The […]
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