Robert Deal, Gannon University
Overfishing is a problem on a global scale, with added effect in regions with rich marine biodiversity, effectively posing a threat to marine ecosystems, food security, and the livelihoods of coastal communities. Overfishing can be defined as the act of catching fish at rates that exceed the ocean’s natural ability to replenish its stocks, leading to long-term declines in fish populations, according to the Cambridge Dictionary. Closed seasons are used to combat this issue; these seasons are characterized as a time during which fishermen are not allowed to catch a particular marine organism. These seasons are useful because they allow fish to replenish their populations during this time. Examples of closed seasons include the Blue Fin, which has a closed season between August 12th through December 31st for HMS Angling and HMS Charter/Head boat permitted vessels according to NOAA Fisheries. The spiny lobster also has a closed season from April 1st through August 5th off Florida and the Gulf states, according to NOAA Fisheries. Many fisheries grapple with diminishing stocks due to a fisherman’s incentive to harvest as much as possible before others do. This commentary analyses how dynamic game theory and biological stock regeneration can help explain overfishing and why implementing closed seasons leads to improved long-term outcomes for both fishers and fisheries. The structure of this commentary can be described as an analysis of how the concept of the tragedy of the commons interacts with dynamic game theory, followed by an explanation of the validity of closed seasons. Specifically, how closed seasons affect long-term profits, and how it occurs through the game theoretic lens, with evidence to illustrate real-world examples. The commentary ends with a culminating explanation of why closed seasons are economically justifiable.
Overfishing occurs as part of the rational decision-making of fishers and can be best understood through the concept of the tragedy of the commons. In a public fishery, every fisher is aware that any fish left in the water today can be taken by someone else tomorrow. This notion strongly incentivizes fishers to harvest as much as possible today. Dynamic game theory vividly captures this repeated strategic interaction; the fishers make decisions over time in an attempt to maximize their own payoff while anticipating the actions of others. With reduced fishing via closed seasons, fish stocks could regenerate naturally, and this conservation would lead to a rise in long-run yields. The dilemma is that no single fisher willingly wants to be the first to reduce their efforts. The resultant effect is a Nash equilibrium in which all players fish at an unsustainable level, not because they want to eradicate the common resource, but because being the sole deviator would lead them individually worse off. This result explains why individual incentives often fail as a motivator to protect common resources and why planned intervention is sometimes a necessity.
Closed seasons become particularly useful as they act as a means to shift strategic incentives towards more sustainable behaviour. As a result of the temporary stoppage of all harvesting, a closed season removes fishers’ fear of losing fish to competitors in the short run. During this stoppage, biological regeneration can occur, which is why most closed seasons are deliberately aligned with spawning or rapid growth periods, i.e.,
The spiny lobsters spawn from March to August, according to the Florida Fish and Wildlife Conservation Commission, which explains why the spiny lobster’s season is between April and August. As the stock rebuilds, the potential catch for the succeeding open season increases, in turn making future harvesting more profitable than it would otherwise be under continuous pressure. In effect, the stoppage of harvesting raises the long-term value of a fishery, which makes restraint a more attractive choice for all players.
The coordinated stoppage fundamentally alters the structure of the game fishers are playing. In a scenario where everyone is required to stop playing at the same time, the destructive Nash equilibrium of continuous harvesting becomes less potent because no single fisher can gain by deviating without facing penalties. Rather, the payoff structure shifts; waiting now produces higher future returns, while exploiting fisheries in the short run has a decreased reward. The resultant effect is that the fishery can move to a more sustainable and profitable equilibrium, one in which stock levels are higher and long-run yields are improved. Significantly, closed seasons can achieve this by changing incentives instead of relying on fishers to be more patient or unselfish in regard to a common resource.
As a real-world example, the Maine lobster has a closed season from June 26th to September 30th according to the Maine Legislature. This time acts as a period for moulting and egg bearing for Maine lobsters. Through protection during vulnerable stages of their life cycle, their stocks can rebound quickly, which lends a hand to the profitability of the fishery. As stated by the Island Institution, Maine’s lobster industry supported nearly 18,000 jobs and generated $725 million in revenue in 2021. This real-world scenario aligns with the predicted results of a game where a temporary pause led to long-term payoffs
Admittedly, closed seasons come with both their strengths and limitations. Strengths include the allowance of stock regeneration, a boost in long-term yield and profits, and closed seasons are generally easy for players to understand and for governing bodies to enforce. Despite these strengths, these seasons can be limited to the compliance of fishermen, as poaching and illegal fishing pose major issues; fishermen must also prioritize future gains, as they will lose some income in the short run. Finally, it is also essential that
Closed seasons align with the biological cycles of fish to be effective. While closed seasons act as an avenue to shift a fishery to a more sustainable equilibrium, their success relies on compliance, monitoring, and long-term prioritization for fishers. Temporary closures also impose economic costs that can pose political difficulties. Thus, although theory supports closed seasons, they work best when imposed in conjunction with enforcement and community cooperation.
Dynamic game theory shows that individual incentives motivate fishers to overexploit fisheries, even at the cost of reduced long-term income. Closed seasons alter these incentives by allowing stocks to rebuild, raising future payoffs, and creating an avenue for fishers to escape the low-payoff equilibrium of continuous harvesting. Although not always a perfect solution, closed seasons can be economically justified where biological growth is strong and compliance is achievable.