Get a tub of wrapped chocolates or an everyday bag of wrapped sweets, which will be used as the ‘fish’ in this activity. Select four types of sweets to represent four commonly caught fish species of differing commercial value – eg tuna (highest value), mackerel (high value), herring (medium value), and anchovy (low value) (these can be adapted depending on your region). Place the four types of sweets on a large table, but deliberately place fewer high-value sweets than the lower value ones, to reflect the natural differences in the abundance of these species in the environment.Divide the class into four different teams, representing different fishing boats. Provide everyone with a ‘fishing net’ each, which could be a stick/ruler attached to a paper box. Get learners to make a circle around the table with sweets, which represents the ‘open access fishery’ where everyone can catch as much fish as they want, but will consequently show the negative effects on fish stocks if fishers do not cooperate.During the game, you should add sweets back into the pile to allow fish to ‘regenerate’ after a certain amount of time and stagger this for each species – anchovy (every 2 seconds), herring (every 4 seconds), mackerel (every 8 seconds) and tuna (every 12 seconds). This will reflect the natural growth of the fish stock.There are three rounds to this game, and the first round should have no rules where each fishing team can fish for as many sweets as they want – this should quickly show the learners that some kind of management is needed when the sweets quickly disappear. After each round, allow learners to have an open discussion about their tactics and what rules they should make to allow them to fish for the higher value fish.With each round, the aim of the activity is for the learners to realize how a collapse of a fishery can occur, and think about what measures will allow them to continue to fish in a sustainable way.

The lesson begins with a game designed to engage learners in the topic of overfishing and provide them with a hands on learning experience. The activity is adapted from "Overfishing – a Tragedy of the Commons" (Dimbleby, 2021). The term overfishing is not introduced until after the game so that learners participate without preconceived ideas about the outcome.

The class is divided into groups of five. Each group receives a large blue sheet of paper representing the ocean, with 100 small balls placed on it to represent codfish. Learners take on the role of fishers, and their objective is to catch as many fish as possible during each of the five rounds, which each last 15 seconds.

To illustrate different fishing methods, learners use different fishing tools:

Simple tool: Chopsticks with one line of tape.

Double tool: Chopsticks with double the tape.

Extra tool: A large spoon.

The rounds are organized as follows:

Round 1: Two learners fish with the simple tool.

Round 2: Five learners fish with the simple tool.

Round 3: Four learners use the simple tool and one student uses the double tool.

Round 4: One student uses the simple tool, three learners use the double tool, and one student uses the extra tool.

Round 5: Two learners use the double tool and three learners use the extra tool.

After each round, fish are added back to the ocean to simulate reproduction. Because the fish population decreases over time, the number of fish that regenerate also decreases: 20 fish are added after Round 1, 15 after Round 2, 7 after Round 3, and 3 after Round 4.

Following each round, learners record their results on a worksheet, noting both the total number of fish caught by the group and the number of fish remaining in the ocean.

Once the game is over and all the data has been collected, a group discussion takes place to explore how the game reflects the fishing industry and to introduce the concept of overfishing.

The discussion is guided by the following questions:

What did you observe happening over time during the game?

What did you think about the different fishing tools that were introduced?

How do the fishing tools used in the game relate to real world fishing practices?

How are these increasingly effective fishing tools connected to the growing number of people that need to be fed?

How do you feel about the use of these fishing tools?

How do you think these fishing tools affect fish populations and the marine ecosystem?

How do you think overfishing affects communities and populations that depend on the ocean for their livelihoods?

After the group discussion, learners work in groups of five to create graphs based on the data they collected during the game.

Graph 1: Fish exploitation over time

Learners create a graph showing the number of fish caught in each round. This graph illustrates the level of exploitation of the fish population over time.

Graph 2: Fish population remaining over time

Learners create a second graph showing the number of fish remaining in the ocean after each round. This graph illustrates how the available fish resources change over time.

Finally, we will discuss the data presented in each group’s tables and examine whether the groups show similar trends. Then, we will project a real scientific table and analyze whether the trends from the most recent years align with the patterns observed in our groups’ data, connecting the game to real world fisheries.