Thursday, January 17, 2013
Traditional fisheries management: Was it rocket science?
I have previously described the insight for fisheries that comes from rocket science, in the form of missile guidance systems. Unlike many fisheries, missile guidance systems identify a clear target, monitor progress towards hitting the target, and, most importantly, make decisive corrections the minute evidence suggests the trajectory is off. The decisive corrections are the biggest difference between missile guidance and fisheries management systems.
The benefit of decisive adjustments is robustness, the quality that for me defines sustainability. Fisheries managed in this manner can sustain healthy stocks and productive catches even when scientific information is highly uncertain or even wildly optimistic. The cost of decisive adjustments is unpredictable catches. Certain fishing operations might be able to weather days, months, or even years of low catch quotas, when environmental conditions or inadvertent excessive catches drive the stock below target levels. However, most fishing operations, including subsistence, artisanal, and small-scale commercial fleets as well as processors and distribution chains, have a strong preference for predictable catches. For them, an alternative path to sustainability is to set conservative catch quotas, which need not be adjusted so decisively.
The above conclusions about fisheries are based on theory. It would be reassuring if there were some evidence that these approaches work to sustain real-world fisheries. Such evidence is tricky to obtain. True proof of sustainability would require centuries, or at least many decades, of consistent management practices during which time fisheries remained healthy. Modern fisheries are not suitable for this analysis because of major technological advancements and the paucity of traditional management systems (meaning that current management is inconsistent with practices from even the recent past). Fortunately, there are traditional cultures where we know something of their fisheries management practices and whether they sustained healthy fisheries. In these cases, we do have evidence that spans centuries to test the concept of rocket science-based fisheries management.
Not all indigenous people were conservation-minded stewards of their natural resources. There are many cases of extinction that can be attributed to overhunting, and some cases where entire societies collapsed, most likely from resource use that failed to recognize limitations or failed to adapt to changes in those limitations. Collapse: How Societies Choose to Fail or Succeed, a thoughtful book by Jared Diamond, details many such cases.
My favorite example of a society which clearly succeeded is the collection of indigenous tribes that lived along the Lower Klamath River in northern California. Their success is described in detail by Arthur McEvoy in The Fisherman’s Problem: Ecology and Law in the California Fisheries, 1850-1980, and under-read gem for anyone interested in fisheries. The tribes sustained healthy salmon fisheries for centuries, and salmon was their principle food source. The strength and splendor of their culture was something to behold, from ornate art to a stable and invincible society. Unable to conquer them, the U.S. Government offered them unusually beneficial treaty terms for Native American tribes, terms that give them substantial say today over water use throughout the entire Klamath River Basin.
Studies of indigenous tribes in what is now the State of California show an interesting pattern. Salmon and acorns (and the deer they supported) were the staple food throughout the State prior to European contact, and there is a strong correlation between the supply of these resources and the pre-contact human population density. In most of the State, the human population was in balance with the available resources. Two groups were exceptions to this rule. One lived along the Santa Barbara Channel, where the human population was unusually dense due to the southerly aspect of the coast, which provides sheltered and reliable access to marine fisheries and thus an additional food source. The other groups lived in the Lower Klamath, and maintained human populations that were smaller than what the resources could provide.
This was no small feat. In the sciences of ecology and economics, the norm is for populations to fully utilize resources. Nature and people thrive when they can and, in doing so, tend to use up what is available. Maintaining a smaller human population would require purposeful underutilization of resources. The specifics of traditional fisheries management in the Lower Klamath included exclusive use of a large fishing weir to catch salmon. The construction of the weir did not begin until after the salmon run started and a priest had blessed it, a process that took 10 days. The weir was then dismantled after 10 days of fishing. Salmon that passed through before or after the weir was in operation escaped upstream. These practices meant that salmon truly was underutilized.
Recall that this strategy is one of the two options to achieve sustainability. And did it succeed! The tribes of the Lower Klamath developed their strength and splendor primarily off of healthy salmon runs managed sustainably for centuries. Their purposeful “waste” of fishing opportunities led to great benefits to society, and serve as proof that a rocket science-based framework can lead to healthy and well-managed fisheries. The feat of the Lower Klamath tribes was even more notable because they managed these salmon runs without the use of formal science. In contrast, we regularly sidestep managing data-poor fisheries under the belief that data is necessary to manage. Clearly we can do better, and a rocket science-based approach will be crucial.