The original passage by Keynes reads:
Even apart from the instability due to speculation, there is the instability due to the characteristic of human nature that a large proportion of our positive activities depend on spontaneous optimism rather than mathematical expectations, whether moral or hedonistic or economic. Most, probably, of our decisions to do something positive, the full consequences of which will be drawn out over many days to come, can only be taken as the result of animal spirits—a spontaneous urge to action rather than inaction, and not as the outcome of a weighted average of quantitative benefits multiplied by quantitative probabilities.[1]
William Safire published an article "On Language: 'Animal Spirits'" in the New York Times on March 10, 2009, stating:
The phrase that Keynes made famous in economics has a long history. "Physitions teache that there ben thre kindes of spirites", wrote Bartholomew Traheron in his 1543 translation of a text on surgery, "animal, vital, and natural. The animal spirite hath his seate in the brayne ... called animal, bycause it is the first instrument of the soule, which the Latins call animam." William Wood in 1719 was the first to apply it in economics: "The Increase of our Foreign Trade...whence has arisen all those Animal Spirits, those Springs of Riches which has enabled us to spend so many millions for the preservation of our Liberties." Hear, hear. Novelists seized its upbeat sense with enthusiasm. Daniel Defoe, in "Robinson Crusoe": "That the surprise may not drive the Animal Spirits from the Heart." Jane Austen used it to mean "ebullience" in "Pride and Prejudice": "She had high animal spirits." Benjamin Disraeli, a novelist in 1844, used it in that sense: "He...had great animal spirits, and a keen sense of enjoyment."[2]
One technique, known as a thermolicer, plunges the salmon into a scalding-hot bath. The hot water kills off the sea lice—and also, sometimes, the fish themselves. Last year, salmon-farming giant Marine Harvest inadvertently cooked 95,000 caged salmon with a thermolicer. Though that killed 95% of the sea lice, it also left the company with 600 tonnes of dead salmon to incinerate. Along with rampant salmon deaths from pesticide treatments, the thermolicer incident caused a 16% drop in the company’s Scottish salmon output for 2016.
There are other options in the works, including lice-zapping lasers, fancy ultra-large-scale pens, and delousing vessels called hydrolicers. But even with the preponderance of government funding from leading salmon-farming countries, new technology is expensive to develop. And for the salmon-farming giants like Marine Harvest, Nova Sea, and others, scale remains a challenge. Meanwhile, a promising sea lice vaccine hasn’t yet borne fruit.
Worse, the conditions that invite sea lice seem to be on the rise. The sea lice life cycle accelerates in warmer temperatures. So it’s hardly surprising that a recent study found that unusually balmy seas helped encourage the 2015 sea lice epidemic that swept British Columbia, Canada.
This all adds up to a pricey problem. And given that the sea lice spread shows few signs of abating—nor does the outbreak of another salmon blight, amebic gill disease—consumers are likely to face steeper salmon prices in 2017. Analysts at the Norwegian bank Nordea expect global supply of farmed Atlantic salmon to stay below 2015 levels for the next three years.
The sea lice epidemic isn’t just hurting fish, farmers and consumers—it also takes a toll on other sea life. Slice is poisonous to crustaceans, though its long-term effects have not been researched. In 2013, a subsidiary of Cooke Aquaculture, one of North America’s biggest salmon producers, pleaded guilty to killing hundreds of lobsters with its use of cypermethrin, a delousing chemical used in Europe but banned in Canada.
The most egregious ecological problem, however, is the fact that the teeming sea lice reservoirs created by farming are devastating wild salmon populations. In that sense, sea lice and humans have something in common: an appetite for Atlantic salmon that nature simply can’t sustain.