The following game is designed to help kids understand the negative effects that European catfish have on the migration of other fish. The game is meant to generate a more dynamic learning environment that allows children to move around and learn in a less academic way. It is important that it is approached as a learning activity and not just a game.
There are a number of fish species that migrate from the Ocean to Western European rivers. This game focuses on allis shad, sea lampreys, and salmon. All three species are affected in their migration by human activities such as fishing, dams, and pollution. Furthermore, all three have been found to fall prey to European catfish. Therefore, since the introduction of the catfish into the western European rivers, all three species have found it harder to migrate and thus to reproduce. The aim of this activity is to adapt the typical game of tag by introducing some of the concepts related to the selective pressure that catfish exert upon the three mentioned species.
The game is based on the articles “Why are catfish bad neighbors for allis shad?”, “What happens to sea lampreys if catfish move in?”, and “What if a salmon meets a catfish?”. It would be useful to read the articles in advance so that children can be introduced to the concepts that appear.
Rules of the game
In order to play the game, the classroom must be divided into 5 groups: allis shad, sea lampreys, salmon, catfish, and humans (representing fishing, pollution, and dams). Ideally, each kid would get a representative sign for the group they are part of; for example, a stamp or a sticker. It is important that there are more prey-fish than predators; the number of each must be adapted depending on the classroom size, but ideally, there would be at least two humans and at least two catfish. The game is best played outdoors, for example in a playground.
Firstly, the space should be presented as a river. From the perspective of a migratory fish, there will be a starting point (where the ocean meets the river) and an endpoint (where they migrate to reproduce). Right before the end line, there should be a mating area where fishes must find another player of their species in order to be able to cross the finish line.
The catfish and humans get distributed along the river and the rest of the fish get placed at the beginning of their river. Once the game starts, the fish must try to get to the end and complete their migration without being caught by the catfish or the humans.
The rules of the game are as follows:
- The catfish and humans will try to catch the prey-fish. If a fish gets caught, it is eliminated and must sit down until the end of the round.
- The goal of the other fish (allis shad, sea lampreys, and salmon) is to reach the mating site, find another fish from their species to mate with, and together cross the finish line.
- When a salmon meets a catfish, it must return to the starting point (because studies show that in the presence of catfish, salmons take longer to pass through a certain point). However, a catfish on its own can’t catch a salmon.
- When a catfish and a human combine (hold hands), they gain the ability to eat salmon. (This is because studies show that when salmon and catfish meet at dams and such places affected by human activity, there is less likelihood of salmon survival.)
- When two allis shad reach the mating point, they must hold hands and spin in circles five times. Only then can they cross the finish line. During this time, they are completely exposed to catfish: they cannot run to escape from them. (Allis shad are less attentive during mating, which consists in swimming in circles, and are therefore more likely to be eaten by catfish.)
- Low-tide areas can be established along the rivers. In these areas, sea lampreys lose their ability to run and are therefore less likely to escape catfish. (Low tide makes it hard for sea lampreys to move and are usually hunting spots for catfish.)
- Two catfish can work as a team (hold hands) to catch another fish. If they do so, that fish is not eliminated but becomes a catfish and starts hunting other fish. (This is meant to represent the rapid growth and expansion of catfish in the western rivers.)
Rules can be added progressively. In fact, it might be wise not to include catfish in the first round. This will allow students to clearly see the impact that catfish have on the migration of other fish. After the game, it would be interesting to encourage the kids to have a discussion on what they have seen and help them connect the game with the theoretical concepts.
You can find a summary lesson on this topic at Case Study on Invasive Species for 5-9th Grade Students.
Find hundreds of other FREE scientific articles about fish, invasive species, migration, water resources, and biodiversity and conservation at Science Journal for Kids – written for kids, approved by scientists.