The Roman Philosopher Lucius Anneaus Seneca (4 BCE-65 CE) was perhaps the first to note the universal trend that growth is slow but ruin is rapid. I call this tendency the "Seneca Effect."

Thursday, January 22, 2015

Sandeels: another Seneca cliff


Originally published on Cassandra's Legacy on Thursday, January 22, 2015




Once you start looking for "Seneca Cliffs" in the exploitation of natural resources, you find them all over the scientific literature. This is my latest find of a production curve where decline is much more rapid than growth: the landings ofsandeels. If you don't know what a sandeel is, here is one: 



In the report (2007), where I found the curve shown above, the authors discuss the causes for the collapse of the fishery, especially in view of climate change. They don't seem to arrive to any definitive conclusion and they don't use the dreaded term "overfishing". But from the fact that trawlerwere used in this fishery, I think it is clear that the fish stock was being destroyed in a process similar to the one that led to the collapse of the whole UK fishing industry. The more resources were aggressively thrown at trying to maintain production, the more the fish stock was depleted. The end result was the rapid collapse observed.

So, as in several other cases, we have a classic example of the "Seneca Collapse", that is a production curve where decline is much more rapid than growth. Below, you can see the Seneca curve as shown in a simulation carried out by system dynamics that takes into account the increased capital expenditure in fishing equipment (the model is described here). 



As Seneca said, "the road to ruin is rapid", indeed.

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