Is Aquaculture Really Saving Fish?

To feed a growing population, we need more food. Amongst the proteins, aquaculture production as both a source and environmental good has become the fastest-growing food production sector. One of the defining memes for industrial aquaculture is the belief that it will

“expand food availability for a growing global population while addressing the problem of overfishing of finite fish stocks.”

Let’s consider a new study on whether that is a promise to be kept or not, beginning with some facts. 

• Aquaculture accounted for less than 6% of fish production 50 years ago; today, it produces more fish for human consumption than capture fisheries. 
• While total human consumption of fish continues to grow, global fish captures have “effectively plateaued,” suggesting that overfishing has declined or been displaced by farmed fish
• Aquaculture has a mixed environmental record, requiring significant energy use, overuse of antibiotics, and local detrimental effects to ecosystems and wild fish stocks. Most farmed fish are predators, requiring other, mostly wild fish, as food. So, there may be pressure placed on fish stocks lower on the food chain. 
• 35% of fish stocks were classified as overfished, 7% as underfished; the remaining majority was considered fished at maximum sustainable levels (MSY). At the same time, to maintain fish captures, we are “fishing down marine food webs, i.e., relying on captures of aquatic organisms from lower trophic levels because higher trophic level species were so depleted.” 

This last fact suggests that wild fish production has reached its ecological limits rather than being driven by improved management or reduced capture efforts. The economic term is that wild fish production has reached its boundary, which gives us a chance to introduce the original thinker in this case study, William Stanley Jevons.

Jevons was a mid-19th-century economist dealing with a practical issue of the time: The Coal Question. He was the first economist to point out that the energy efficiencies from using coal-burning engines resulted in lower coal prices and, paradoxically, the use of more coal. [1] Jevon’s Paradox is an unintended and perhaps unanticipated consequence of the improvement in the efficiency of production. In terms of fish, our greater efficiencies in fishing, which now include wild and farm “caught” fish, have not resulted in fewer fish being captured and consumed but more. 

The economic effects of Jevon’s Paradox can be direct, in this instance, lowering the cost of fish and increasing consumption, and indirect, leaving more of the food budget for other items or budgets – both traditional economic outcomes. However, a third effect involves the broader economy. In Jevon’s original thesis, steam engines replaced human labor, just as tractors replaced oxen in farming. Aquaculture, which creates a new type of commodity, causes multiple effects in the broader economy, including changing market structure, consumption, use of resources, and even lifestyles, all difficult to predict and all transformative. 

The paperless office

Perhaps you remember the meme of the last century - the rise of the digital office, resulting in the paperless office. With everything captured by the computer, the need for paper would plummet. Of course, as we learned, the use of paper rose quite a bit with the introduction of the digital economy. This demonstrates what economists call the displacement paradox – when a substitute could, in theory, replace another but does not. [2]  This paradox, along with Jevon’s, go hand in hand. Jevon addresses efficiency how resource use per unit of production should reduce overall resource use; the displacement paradox describes to what degree one resource is substituted for another. 

When considering both paradoxes, the researchers of our aquaculture study are left to conclude that:

“Aquaculture is not tending toward replacing or conserving wild fish globally, but rather adding to the food supplied from marine systems. This may be deemed a positive outcome, i.e., increasing food supply, but that is not the same as sustaining healthy fish populations and marine ecosystems.”

They term this paradoxical outcome as the tragedy of the commodity, a wordplay on the idea of the tragedy of the commons that users of commonly held but not owned resources tend to benefit their self-interest and socialize the cost. With a resource becoming a commodity, fish, in this example, larger political, economic, and cultural forces and market forces shape outcomes. While aquaculture provides “a relief valve for fishing pressure and environmental changes, and supplying sustainable aquatic food for a growing global population,” because of Jevon’s and the displacement paradox, it does not necessarily create sustainable healthy fish populations.  

In a system based on commodities, production, and its efficiencies take precedence over sustainability. That is why much of the discussion around aquaculture in the scientific literature is like the work of Frederick Taylor, the father of the time clock; measures of production efficiency, e.g., pollution, disease, use of antibiotics, and fish-in, as food, fish-out, as product, ratios (FIFOs). These are measures of cost and loss reduction, not sustainability. 

The researchers point to Salmon aquaculture to illustrate their concerns over prioritizing market forces. Despite the technological advances that have increased productivity, e.g., improving the feed-to-fish ratio (FIFO) and rapidly growing production of farm-raised Atlantic Salmon, the wild Salmon population has caused the spread of disease and “genetic mixing” to our wild Salmon stocks. While the US has a breeding program for wild Salmon, the most significant impediment to the return of Salmon to greater populations are dams that impede their journey from home to the sea.  

While they go on to couched many of their arguments around social and environmental justice, their point that technology alone will not render fishing more sustainable is valid. Sustainability requires a change in our human behavior, which is more complicated than a technological fix. For those who might wonder why we should consider the plight of the Salmon, I would offer a more self reason. Commodification, Jevon’s paradox, and the paradox of displacement are not concepts that are restricted to fish or coal. In the last few decades, healthcare has been commoditized. While much has been made over increasing production efficiencies in the delivery of care by providers (terms found in Jevon’s thesis) and the rise of alternative and complementary medicine (terms found in displacement), little is being done to change our lifestyles and institutions to support healthier living so we need less, not more, of those now more efficient and diverse health services.

So, what have we learned? Industrial aquaculture is great at ramping up fish production but not so great at saving the oceans. It’s Jevon’s Paradox all over again—making things more efficient doesn’t mean we’ll use less; it just means we’ll consume more. Without fundamental changes in behavior and a focus on true sustainability, we’re just chasing our tails—or, in this case, fish.

[1] The more economically inclined will recognize that lower coal costs resulting in increased demand is not paradoxical but reflects typical economic views of supply and demand. What is paradoxical is that the savings in coal use from engine efficiency resulted in more, not less, coal use. 

[2] Here is a fun fact that I just learned. One of the earliest examples of the displacement paradox was the assumption that petroleum, discovered in 1859, would replace whale oil as a fuel and lubricant. Whaling increased, in part, due to ships powered by fossil fuels. It ended more than a century later when it was no longer financially viable. 

Source:  Why aquaculture may not conserve wild fish Science Advances DOI: 10.1126/sciadv.ado3269

 Image of William Stanley Jevons by Unknown (via University of Manchester Libraries) - This file has been extracted from another file, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=141730235