Someone needs to show the International Commission for the Conservation of Atlantic Tunas (ICCAT) a simple economic/math thought experiment because they do not quite understand how overfishing can wipe out a species. The population of the Atlantic bluetin tuna has declined to below 15 per cent of pre-fishing levels according to the WWF.
In our simple thought experiment, let’s assume that there is a small pond. In that pond, there are 100 fish. Now, let’s say on the first day 10 fish are caught, but the fish population is not given enough time to recover, which means there are now 90 fish total in the pond. The market for fish from that pond increases so more fishermen have an incentive to enter it (we will assume perfect competition so there are no barriers to entry) and the existing fishermen have an incentive to catch more fish because the prices for fish have increased. On the second day, a total of 20 fish are caught because of the increase in demand and the entry of new fishermen. The total number of fish caught now is 30, while the number replaced is 0 meaning there are 70 fish remaining. On the third day, more fishermen enter market and more fish are caught; let’s say 30 fish are caught and once again 0 are replaced. The total number of fish caught now is 60, while the remaining population is 40. It’s apparent in our model that by day 4 all the fish will be gone in our little pond if the number of fish caught is 40 with inadequate time for the fish population to recover.
What happens next in our story? The fishing industry has now collapsed because the fish are now extinct. There’s social welfare loss because there is a demand for fish, but there is no supply. All the fishermen in the industry are now unemployed. Finally, there is a negative externality because an empty pond is considered ugly.
At its next annual meeting, the ICCAT should follow its scientists’ advice and enforce policies on the 48 contracting parties to stop overfishing and allow the Atlantic bluetin tuna population to recover. Not only does it ensure the survival of the species, but it also ensures the survival of the bluefin tuna market.