The problem of truth

I read an interesting (and rather infuriating) opinion piece on salmon in the Gridley Herald a few weeks ago, claiming that salmon populations on the Klamath River in northern California are doing just fine. Gridley is a small town in the Central Valley south of Chico. The author, James Finses, based his claim on one good year of salmon returns, as well as bashing the groups he disagrees with (more details below). While making me writhe internally, this piece also got me thinking once again about denial, and how we shape truth.

The problem is that people have different versions of the truth. Scientists version of truth takes the form of testable hypotheses that are “proved” (or fail to be rejected, if you'd prefer), or quantitative models, but that’s not how people work. People, in general, are most likely to believe what they see (first-hand data), and this is tempered by what they want to see (which is where denial comes in). Since I happen to be watching football right now (don’t be too shocked…I was coaxed to the bar by my husband), the analogy that comes to mind is if a team does well the three times in a row you happen to watch them, you’re more likely to believe that they’re good rather than the long-term statistics that tell you they’re terrible. In short, we’re more inclined to believe what we see right in front of us (and especially when we like what we see), rather than trying to put things in the larger context… especially when it’s inconvenient or displeasing to do so. Thus, we can easily create a convenient reality, when so inclined.

This problem of truth extends to opinions surrounding salmon fisheries management. There’s lots of data and scientific papers showing that our salmon populations have crashed in the past century, but there is also tremendous economic, cultural, and social pressure to keep fishing. This creates a situation where there are a lot of people with different opinions and goals searching for a slippery truth (i.e. how do we best restore/maintain salmon populations).

Restoring salmon populations is not an easy or straightforward task, and can demand innovative and sometimes unpopular (with some) approaches, such as dam removal, fishing restrictions, or expensive fish ladders, all of which can inspire heated controversy. This is the case on the Klamath River in northern California where I do my research, and where there are 4 dam removals planned for 2020 in order to help restore fish populations (including ESA-listed Coho). On the Klamath, there are many interest groups who care about both fish and water flows, including fishermen, native tribes, rafting companies, farmers, and fiery locals.

Returning Chinook salmon on the Klamath River

And so when record numbers (~380,000) of Chinook salmon were projected to return to the Klamath River this year — a run size close to historical returns for fall Chinook — it is no surprise that there were people, including James Finses of Gridley CA, eager to jump at the opportunity to claim that salmon populations are doing just fine. In his opinion piece, Finses is quick to point out that the fish are returning despite the fact that we still have dams, and that “the dirty, unscientific data brought forth by the tribes, enviros and other whacko groups was wrong all the time.” The problem with Finses’ argument that one good year of salmon returns means that salmon populations are fine is that salmon populations are incredibly variable year to year, and the success of a particular cohort depends on numerous conditions including favorable river temperatures and ocean conditions (abundant plankton and low predator numbers). In the end, he states that “the salmon are back in record numbers with all the dams to help them.” I find this last sentence particularly interesting, since it reflects the desire to not just disprove undesirable truths, but to use this small piece of evidence (one year of good salmon returns) to reshape the truth (i.e. dams must be helping the fish). Whether Finses actually believes this statement or not, the fact remains that humans are susceptible to incredible willful short-sightedness when it suits us. So in questions relating to fisheries management, the truth very quickly becomes a slippery shadow, swathed in politics and emotion, often taking different forms for different people.

Fish ladder on John Day River dam

My husband came across another example of this truth-shaping during his research on dam removal, when talking to a local about fish ladders. Fish ladders are structures built into some dams that allow for anadromous fish migration – they are usually a series of small steps and pools with sufficient flow to attract fish to them. While having fish ladders is better than providing no fish passage at all, they are only somewhat successful; some problems include increased predation (predators, such as bass or birds, can sit at the end of the fish ladder, picking off a tasty meal as the salmon funnel through), and possible delay and additional energy demand on the fish (especially as they pool up at the bottom, awaiting their turn in the limited space). However, having a fish ladder is somewhat of a band-aid fix, and can make it seem like the fish are doing fine, especially since it often causes the fish to pool up, so that visually it appears that there are a lot of fish. As the local remarked to my husband, ‘the fish are just hanging out below the dam, “taking their time.”’

So will one good year of salmon returns make us forget those that have come before? As scientists, the answer is no. But as humans, we are susceptible to our emotions and personal biases.