Student Worksheet to Simulate Ocean Sampling

Over 15 years ago I went to one workshop where a teacher showed us one of her teaching ideas. It was great, but the worksheet was a copy of a copy that was originally not very good, but the lesson concept was still great. She took a large grid and put letters into random grid location to represent different animals in the ocean. She then made an overhead transparency of the "simulated ocean" area and projected it on the wall. She had students come up to the overhead projector and throw (cast) a rubber-band on the transparency. Whatever letters was fully inside the rubber-band were animals that were captured in the simulation.

Students were required to make several "casts" and record their results. From the data collected they were to make projections of how many of each organism they thought would be inside the entire grid area based on the total number of grid sections and the numbers in their data. After doing this with students that came up to the projector, she passed out similar sheets to groups of 2 or three students. They did the sampling experiment at their desks and recorded the results.

It was a few years later, that I pulled that lesson from my files and decided to remake the worksheet. I of course now used a computer to produce the grid and searched the internet for graphics with sea creatures. After finding a few graphics that I thought were suitable to work with I made extensive modifications to the graphics, by changing them to drawings, resizing them, erasing portions not needed, resizing them, and redrawing major sections as needed. I then placed them on the worksheet, but reduced their brightness to have them fade into the background more. These were free graphics on then net from the start..

When I do this lesson I use hair ties which are a bit heavier and which seem to stay open better. Any time students use rubber-bands there is the potential for problems. You could even use string or simulated cast nets made on transparency film. This lesson could be modified for sampling of a jungle environment, a grassland environment, a mountain environment etc. The graphic shows you basically how my worksheet looks today.

While working on my biology degree I had to do sampling experiments. I had to walk through a golf course late at night gathering any "Bufo terrestris" (a type of toad) that I saw and tag them. Then each following night I did this and eventually I would start to recapture ones I had already tagged. The ratio of tagged to untagged toads captured was directly proportional to the total population of toads in the area. Of course, you can imagine being stopped by the police at midnight roaming around a golf course with a flashlight and trying to explain you are capturing and tagging toads. I had to do that twice in one week. In any case it was a great experience.