Gold Fish Lab
Collaborators- Garret and Tom
Abstract- We took handfuls of goldfish out of a bag of rainbow goldfish and put them on a table. Once we did we counted the total amount of goldfish, and then counted the colored goldfish and marked them as tagged. We did that 20 times and got the average percentage of how many fish were tagged. Once we did, we predicted the total population of the goldfish. We under estimated the population size by 17.6%.
Problem- Is tagging a good way to predict population size in the wild?
Hypothesis- I think tagging is only good for telling when and where an animal is.
Materials- Goldfish and a plastic bag
Methods-
Data-
Abstract- We took handfuls of goldfish out of a bag of rainbow goldfish and put them on a table. Once we did we counted the total amount of goldfish, and then counted the colored goldfish and marked them as tagged. We did that 20 times and got the average percentage of how many fish were tagged. Once we did, we predicted the total population of the goldfish. We under estimated the population size by 17.6%.
Problem- Is tagging a good way to predict population size in the wild?
Hypothesis- I think tagging is only good for telling when and where an animal is.
Materials- Goldfish and a plastic bag
Methods-
- Obtain a bowl with your fish.
- Do NOT count the number of fish in your pond yet!
- Have one member of your group remove a large handful of fish.
- Count the number of fish you just removed and write it in the table below.
- Replace these fish with “tagged” fish (in this case, colored “fish”)
- Mix your pond well to redistribute the tagged fish among the other fish.
- One member at a time (and without looking), remove a handful of fish and record the number of total fish in the sample, the number of tagged fish, and figure out the percentage of tagged fish. (see chart)
- Return your handful to the bowl!!
- Continue with this until you have taken 20 samples.
Data-
Questions- 1. What is the mean (average) of your percent tagged fish from your 20 samples?
-24.3%
2. Using the following formula, determine an estimated population for your pond:
-103
Population Size = (Number Originally Tagged/Mean of the Sample %’s) x 100
3. Now, actually count the number of fish in your bowl: 125 fish
4. Find your percentage error by using the following formula: 17.6%
100 x (Your estimate of population - Actual size of population) / (Actual size of population)
5. Does this method appear to be an effective way to assess population size? Why or why not?
- No, there are too many variables and the original prediction was very off
6. What concerns should a biologist have about a species’ habits before (s) he uses this method to approximate the size of a population?
- They would have to worry about migration, birth, and death rates (Temperature & climate)
Conclusion- We discovered that tagging is not an effective way of measuring population size. We were able to estimate the population size, except our estimate was very off. In "Why tag fish?" it explain several ways to, more effectively, tag fish for research. However, tagging fish is still not an effective way to measure population change. Tagging is only good for measuring where a fish is and when they were there. Tagging should not be used for measuring population change.
-24.3%
2. Using the following formula, determine an estimated population for your pond:
-103
Population Size = (Number Originally Tagged/Mean of the Sample %’s) x 100
3. Now, actually count the number of fish in your bowl: 125 fish
4. Find your percentage error by using the following formula: 17.6%
100 x (Your estimate of population - Actual size of population) / (Actual size of population)
5. Does this method appear to be an effective way to assess population size? Why or why not?
- No, there are too many variables and the original prediction was very off
6. What concerns should a biologist have about a species’ habits before (s) he uses this method to approximate the size of a population?
- They would have to worry about migration, birth, and death rates (Temperature & climate)
Conclusion- We discovered that tagging is not an effective way of measuring population size. We were able to estimate the population size, except our estimate was very off. In "Why tag fish?" it explain several ways to, more effectively, tag fish for research. However, tagging fish is still not an effective way to measure population change. Tagging is only good for measuring where a fish is and when they were there. Tagging should not be used for measuring population change.