10. Gone Fishin' - Background

Teacher Background
The tragedy of the commons was initially proposed as a hypothetical model to illustrate a much larger societal problem. In colonial times, there was often a common pasture (the commons) where all citizens of the town could take their livestock for grazing. Each individual farmer and his animals is motivated to use this pasture land to get the maximum benefit possible. However, as more animals use the resource, the pasture gets trampled and overgrazed until there is no grass left for anyone. Thus, if each farmer is motivated simply to maximize personal benefit, thus using the pasture as much as possible, the resource is soon no good to anyone.

Similarly, the ocean’s supply of fish is a common resource that is rapidly being depleted. The basic issue is that since 1950, the fishing industry has quadrupled its catch. According to the United Nations, 15 out of the 17 world fisheries are overfished or depleted. 90% of the large fish species in the oceans have been fished out in the last 50 years. In short, fish are being taken from the oceans faster than they can reproduce and grow. Many fisheries have already collapsed, sending hundreds of fishermen and women out of work. Without clear international controls and regulation, soon there will be no more fish in the seas. Many articles have been published in recent years describing the problem. For example, see the Economist, May 2005, Science Magazine, December 2003, and the San Francisco Chronicle, October 2004.

This activity is a way to help students recognize the problem by catching candy, peanut and cracker fish from paper plate oceans. Students will spend 4 years fishing in their oceans. Each “year” the students have 30 seconds to fish for as many fish as they can catch using straws and masking tape as their poles and hooks. Each fish has a different monetary value and each student much catch a minimum dollar amount of fish in order to stay in business the following year. Then the remaining fish in the ocean have a chance to reproduce. There must be at least 2 fish of that species to reproduce. In addition, the fish in their oceans have a food web and must have their food source still available in order to survive.

At the end of the game, some oceans will likely have overfished their fishery until there are no fish left. Others will have developed a strategy in order to maintain a sustainable fishing industry. The discussion at the end will look at the problem of overfishing and solutions that lead towards sustainable resource management. The stage is then set for solid discussions of resource management strategies for other shared environmental resources.

Student Prerequisites
Students need a solid understanding of food webs (see Food Webs activity) and experience with monitoring population changes over time through tables and graphs (See Hare and Lynx Population Change activity).