The Aquafarmer: Your role in this lab

In conducting this exercise, you should imagine yourself as an applicant for the job of manager of a real-life fish farming operation.  Suppose your dear Aunt Pearl has been running this farm in Virginia for the last 35 years and is planning to retire.  You want to show her that you have the problem-solving skills to take over the operation for her.  While you may not think this career choice is particularly appealing, you know from Pearl's example that there is big money to be made here, you can be your own boss, you'll have flexible work hours, and you'll be able to keep the business in the family.  Before Pearl hands the operation over to you, she's asked that you use this simulation to demonstrate that you can handle the responsibility.

Your first step will be to get acquainted with some of the ecological concepts involved.  After that, you'll be working with a relatively easy to manage fish: rainbow trout.

If you look online, you might find the following description from Helfrich, Orth, and Neves (1997):
Rainbow trout is the most widely grown and preferred coldwater fish for farming. This species possesses a number of desirable traits, including its rapid growth to a large size, high survival, adaptability to artificial feeds, high quality flesh, high market demand and value, well known growth requirements, and ready availability as eggs, fingerlings, and adult stocks.
As a sportfish grown for stocking recreational waters, rainbows are highly regarded as spectacular fighters and leapers, and for their healthy appearance, color, and table quality. Rainbow trout are native to the western United States, but have been widely transplanted in the eastern states. Self-reproducing populations occur in Virginia's coldwater streams.
Rainbow trout are excellent food and sportfish.

Pearl has established that before you can take over the farm, you need to show that you can earn in excess of $235,000 profit for five consecutive years.  She is requiring you to write a report explaining how you went about experimenting with the rainbow trout in the pond, working with stocking density, dissolved oxygen, and protein content.  Once you've done that, she wants you to come back and work with a "mystery fish," one that is tolerant of only certain conditions.  Again, she'll expect you to make a profit; and again, she'll need you to write a report on your process.

You see, Aunt Pearl is interested as much in the process of how you go about finding optimum values for the different variables as she is in the bottom line of profit.  In this simulation, profit is dependent on the variables you will be manipulating.  We call it a "dependent variable."  You'll have to show her both your process and the data showing your profit in your report.  She will expect to see that you had some good "years" in the simulation as well as some bad years.  She knows firsthand that a fish farmer must cope with both good and bad years.  Disease, drought, flooding, or changing conditions in the water due to surrounding human activities can all be causes of the bad years.  Fortunately for you (and for her, and for the fish!), this simulation allows you to have good and bad years without losing actual money or killing actual fish.