Are There Scientific Criteria for Putting Short-term Conservation Ahead of Learning? No.

Richard A. Hinrichsen

• Abstract
• Response to K. N. Lee
• Responses to this Article
• Literature Cited

Kai Lee asks "Are there clearly articulated scientific criteria for putting short-term conservation ahead of learning? (That is, are there conservation situations where we know enough not to need to worry about surprises?)" There can be no such scientific criteria, even in the most trivial of circumstances, because it is really a question of societal values. In cases in which societal values favor conservation of an endangered or threatened population, reliable learning is unlikely to be placed ahead of short-term conservation, partly because it is uncertain whether learning will really improve the prospects for population recovery. Given the prevailing societal values and scientific realities surrounding endangered or threatened populations, the question is not when short-term conservation can objectively be put ahead of learning, but whether either can be accomplished.

KEY WORDS: Snake River, adaptive management, chinook salmon, endangered populations, learning, scientific criteria, short-term conservation, societal values.

Published: June 13, 2000

Kai Lee (1999) asks "Are there clearly articulated scientific criteria for putting short-term conservation ahead of learning? (That is, are there conservation situations where we know enough not to need to worry about surprises?)" There can be no such scientific criteria, even in the most trivial circumstance. Whether to put short-term conservation ahead of learning is not a scientific question; it is really a question of values. At most, scientific criteria can inform this choice. Even when learning is nearly impossible (e.g., environmental noise overwhelms the largest potential experimental response, or achieving replication and control is not feasible), a decision maker may value "learning" to delay costly or politically risky short-term conservation measures. When short-term conservation is nearly impossible (i.e., extinction probabilities are extremely high), the U.S. Endangered Species Act may force "safe" conservation measures instead of learning. (In general, however, the dichotomy between short-term conservation and learning is false; it is difficult to learn from an extinct species, so learning may, in fact, require short-term conservation.)

Let us now consider more fully the challenge of putting learning ahead of short-term conservation in the context of societal values and scientific realities. Suppose that the status quo is abhorrent to society because of a valued population's high extinction risk and escalating costs of failed management, so that there is opportunity for novel action. This may be the case Kai Lee had in mind when he posed his question. In this urgent situation, if the choice is between learning and short-term conservation, it should not be surprising to see short-term conservation preferred by a decision maker. Removing the immediate threat to the population will satisfy society (if not too economically cosstly or socially disruptive), but increased learning per se will not.

Can reliable learning be accomplished in this urgent situation, even when short-term conservation objectives take priority? If we focus on substantive learning through adaptive management, learning that could identify factors that strongly affect population growth, probably not. If a population is nearly extinct and the will to foster recovery is strong, then ignorance of what limits population growth will favor policies that "do everything feasible thought to be good, all at once and on all subpopulations" until the population rebounds. Therefore, the favored policy will not provide replication and control and, consequently, it will not provide reliable learning. In the Columbia River arena, for example, there is pressure to improve the survival of threatened Snake River chinook salmon on many fronts at once (hydropower operations, hatcheries, harvest, and habitat) within the next 5-10 years, and at the end of this period to determine whether the actions were successful to inform a decision on dam breaching. When using population growth (e.g., spawner-to-spawner ratio) as the response variable, this policy will provide but a few years of data and will confound the effects of numerous actions. After 5-10 years of "experiment," it will probably not be known which (if any) of the actions (aside from harvest) produced changes in the Snake River chinook population growth rate. Would a more scientific, experimental approach be preferable here? Experimentalists should be concerned with the real possibility that, after all is said and done, the operation was a success (there was learning), but the patient died (extinction).

One solution to avoiding the conflict between short-term conservation and learning is to answer important scientific questions by experimenting before population numbers become critically low. This is a viable solution for density-independent survival or reproductive processes, but it presents a difficulty for density-dependent survival or reproductive processes. The information gleaned when population numbers were high may not apply at low population levels because there may be a population size-treatment interaction. For example, what we learn about efficacy of salmon carcass introductions at high population numbers (to restore nutrient loads) may have little bearing on the effect of salmon carcass introductions at low population numbers.

An argument in favor of putting learning ahead of long-term conservation is that learning may be necessary for longer term conservation. But a counter-argument is that short-term conservation is also necessary for longer term conservation and, next to the obvious benefit of short-term conservation, the benefit of learning is uncertain and intangible. This occurs partly because ecological science is often situational, so that what is learned about one population in one place at one time is not readily transferable. Given the prevailing societal values and scientific realities surrounding endangered or threatened populations, the question is not when short-term conservation can objectively be put ahead of learning, but whether either can be accomplished.

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Lee, K. N. 1999. Appraising adaptive management. Conservation Ecology 3(2): 3. [online] URL: http://www.consecol.org/Journal/vol3/iss2/art3