Putting a Price on Salmon
In a society that conducts environmental debates in the language of business, it makes sense to put a price tag on salmon.
Not farmed salmon, those artificially-colored cows of the sea, but wild salmon — majestic fish who once swam in the hundreds of millions through the rivers and streams of North America, and now cling precariously to life in a small fraction of their former range.
Of twenty-six salmon populations in the United States, twenty-one are either threatened or endangered, or ought to be. (The federal government has had trouble interpreting its own advice.) That’s led to conflicts over the effects of commercial fishing, dams, agriculture and aquaculture on wild salmon, and often-bitter arguments over whether and how much money should be spent to save them.
Unfortunately, translating the worth of wild salmon to a dollar figure is easier imagined than done. Such a calculation needs to include dozens of factors, from beer money spent by recreational fishermen to the salmon’s role in attracting tourist-pleasing bears to the personal value of an environmentalist’s sentiments.
(The phrase “What is a salmon worth” returns exactly two Google hits. One is asked rhetorically by an environmental lawyer writing about the difficulty of claiming damages against Superfund polluters. “There is no generally accepted way to answer these questions,” she says.)
But in the absence of an accepted way, an educated guess is quite useful. To save the salmon — or to decide whether they’re even worth saving — we ought to have some rough approximation of their worth. That’s going to be the topic of my Hive Mind reporting on the economics of extinction in fish, and I figured I’d start with the value of nutrients carried by salmon inland from the ocean.
The five species of Pacific salmon — for simplicity’s sake, I’m restricting this part of the analysis to the Pacific Northwest — spend most of their lives feeding at sea, and return to the streams of their birth to spawn and die. Nutrients from their bodies wash downstream or are carried onto land by the animals who eat them. From another perspective, those salmon are swimming bags of fertilizer.
Because most of the compounds in a salmon’s body possess subtle but telltale molecular signatures, biologists can use soil samples to estimate the nutrient levels historically delivered by salmon. The numbers are staggering: about 380 million pounds of sheer flesh annually, including 12 million pounds of nitrogen and 1.5 million pounds of phosphorus, two foundation-of-life elements. Some ecosystems appear to have received most of their nutrition from salmon.
Of the dozen or so salmon researchers and environmental economists I emailed, none knew of research quantifying the nutrients’ value. But this can be estimated, in back-of-the-napkin fashion.
According to the USDA’s 2008 fertilizer price estimates, nitrogen cost $1,333 per ton, and phosphorus $1,600 per ton. T hat puts the total annual historical value of salmon nitrogen at $8 million, and phosphorus at about $1.2 million. Of course, there are many more nutrients in a salmon’s body; to estimate the cost of these, I turned to Salmon Carcass Analogues — dried fish pellets used in a small experiment by Idaho biologists attempting to restore traditional nutrient balances. Manufactured by aquaculture feed company Skretting, these cost about $1 per pound; assuming that salmon bodies are, like humans, about 75% water, this puts the annual value of historical salmon biomass at $285 million.
Those figures don’t reflect the labor value of the salmon, who so conveniently delivered themselves down tens of thousands of miles of coastal rivers and streams. Assuming that key salmon nutrients are efficiently absorbed in artificial form by ecosystems — an uncertainty, in the same way that people might metabolize vitamins differently in meals than pills — distributing fertilizer or fish meal would cost many times more than raw materials alone. So I’m conservatively pegging the nutrients’ value at several billion dollars
What can be done with this $3 billion figure? I have no idea. I’d love to see the framework, if not the number, applied to cost-benefit analyses of salmon conservation. The long-term effects of nutrient deficits in regions where salmon have vanished are still uncertain, and may not be apparent for decades, but some researchers speak of ecosystem failure. That may be overly dramatic; there are, after all, other sources of nutrients, and perhaps some forests in the Pacific northwest will simply be smaller, hosting less life; they’ll be less “productive,” in the vernacular of biologists.
What’s that productivity worth? That’s another debate altogether. But it’s worth keeping in mind that salmon migrations have until now continued uninterrupted for 10,000 years, if not longer. The Pacific northwest grew in part on a $30 trillion line of credit, and we’ve nearly cut it off.
Image: California Department of Fish and Game, via Zoologix