It is frequently reported that fish stocks are in decline worldwide.
For example, the Food and Agriculture Organization of the United Nations warns that more than 30 percent of fish stocks are being harvested at unsustainable levels.
This sentiment is echoed by the World Wildlife Fund, Greenpeace, Oceana, and the International Union for the Conservation of Nature, among others.
“Unsustainable” in this context is a reference to questionable fishing practices – practices like bottom trawling that indiscriminately kills everything caught in the nets.
Dynamite and cyanide fishing are also unsustainable practices, especially around coral reefs.
Overfishing is different from unsustainable fishing.
Overfishing is a consequence of unsustainable fishing. It refers to the declining number of individual fish in a given species. Overfishing occurs when there are not enough fish left of a species to reproduce in numbers large enough to maintain a healthy population.
Presumably, overfishing can be the road to extinction, and a number of valued fish species face this prospect today.
As for sardines, due to their nutritional value and ease of catch, they have a special role in commercial fishing. They are simple to process and preserve through canning, smoking and freezing. And they are a common source of fish meal for aquaculture.
However, sardines also play an important role at the base of the food web – as prey for tuna, for mammals like seals and dugongs, and for cetaceans – whales, porpoises and dolphins.
In the Philippines, sardines make up 15 percent of the total fish catch year in and year out. Due to the cheap price and high protein content, they are a prized food source.
However, the size of the sardine catch in the Philippines has whipsawed over the past few years, raising deep concerns about the viability of several species.
Oceana Philippines Vice President Gloria Esterizo was quoted as saying that the total fish harvest has been on the decline in recent years, including the catch of sardines.
Based on data from the Philippine Statistics Authority, she said that the total sardine harvest dropped from 442,045 tons in 2010 to 325,226 tons in 2019.
Recent data for the Philippines are few and hard to come by, but according to the PSA the third quarter of 2024 saw a 5.1 percent decrease in the size of the total fish harvest compared to the same period in 2023. The harvest of B Bali sardines, or Sardinella lemuru – one of nine species in Philippine waters – was down 6.7 percent.
Bali sardines are known locally as tamban.
This is an example of what sociologists call “the tragedy of the commons”.
The tragedy of the commons was first spelled out by English economist William Forster Lloyd in a pamphlet in 1833, but the idea was picked up and popularized more than a century later by the American ecologist Garrett Hardin.
In 1968 Hardin, who had a PhD from Stanford University and was a professor at the University of California at Santa Barbara, published an article in Science magazine titled “The Tragedy of the Commons”.
In that piece, he invites readers to envision a cow pasture near a village that was shared by all the villagers. Any villager with cows could set their cows free to browse in the common pasture, called “the commons”.
In English, “commons” means “a shared resource” – a resource shared by all members of a community, including natural resources.
The “tragedy” arises when some villagers realize the personal benefits of adding more of their own cows to the pasture.
However, this results in overgrazing, and the consequence of overgrazing is the eventual destruction of the cow pasture, which is a resource supposedly shared by all of the villagers.
In the current context, the world’s oceans are the commons, and commercial fishing fleets are the main culprits, exploiting marine resources in unsustainable ways.
Unfortunately, sardines are difficult to raise in aquaculture: Aside from a unique freshwater species in Taal Lake called tawilis, they are a pelagic species, meaning that they range freely over the open seas, and they travel in gigantic schools ranging from hundreds of thousands to millions of fish.
As for tawilis, they are now classified as an endangered species due to overfishing.
Aware of concerns about the decreasing size of the sardine catch, the Philippine government recently created the National Sardine Management Plan. The plan was signed by former Agriculture Secretary William Dar on May 15, 2020, and it appears to have had a mitigating effect.
Aside from overfishing, there are many other examples of the tragedy of the commons. Climate change is arguably the ultimate tragedy of the commons, but also included are forests, the atmosphere, fresh water, and arable soils.
Bryce McIntyre, PhD, resides in San Andres. He holds a doctoral degree from Stanford University, Palo Alto, California, USA.