Something's Fishy Lab

Collaborators: Alex King, Micaela Strickland, Habiba

Introduction: In order to determine the population of a variety of species, biologists use something called tagging.They capture and tag a sample of animals. Then release the animals and allow them to naturally "redistribute themselves". Then they would start taking random samples and calculating the percentage of that sample thats alreaady taggged. This way biologists can theorize the population size of that species.

Problem: Is it possible to estimate the size of the population by using the mark-recapture method?

Hypothesis: If the 'fish' are marked and recaptured repeatedly, then it will be possible to estimate the population size of the species.

Parts of the Experiment:

Control group: 1st sample of tagged fish

Experimental group: Rest of the population

Independent Variable: Tagged fish

Dependent Variable: Untagged fish

Controllled variable: "handful"

Materials: Brown paper bag, undefined amount of beans (fish), 4 hands

Procedures: *See something's fishy lab sheet

Data:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Data Analysis: The number of taggeg fish in each smaple changed alomst every time and so did the total sample size. There was no correlation between the two.

Conclusion: The mean of our percent tagged fish from the 20 samples is 34.3. Using the formula given, our estimated population is 29. The percetage error was 42%. I don't think this was vey effective in our school setting because our handfuls were always different, so our sample size was different, thus it changed the number of tagged fish in each sample.

Citation:"Estimating Population Size." Estimating Population Size. N.p., n.d. Web. 23 Sept. 2014.