Abstract
In order to count a given number of goldfish crackers, we used a method called tagging. I figured that since it was used in the real world that it would efficient and accurate. Though after we finished this lab, I came to the conclusion that this was infact, not an efficient method of counting population size. Although it also occurred to me that other things can factor into population, and that there's really no way to count every fish in the sea.
Problem
Is tagging an effective method of estimating fish population size?
Materials
Goldfish crackers, paper plate, calculator, ziplock bag
Method
1. Obtain a bowl with your fish
2. Do NOT count the number of fish in the pond!
3. Have one member of your group remove a large handful of fish
4. Count the number of fish you just removed and write it in the table below
5. Replace these fish with “tagged” fish (in this case, colored “fish”)
6. Mix your pond well to redistribute the tagged fish among the other fish.
7.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)
8. Return your handful to the bowl!
9. Continue with this until you have taken 20 samples.
Data
In order to count a given number of goldfish crackers, we used a method called tagging. I figured that since it was used in the real world that it would efficient and accurate. Though after we finished this lab, I came to the conclusion that this was infact, not an efficient method of counting population size. Although it also occurred to me that other things can factor into population, and that there's really no way to count every fish in the sea.
Problem
Is tagging an effective method of estimating fish population size?
Materials
Goldfish crackers, paper plate, calculator, ziplock bag
Method
1. Obtain a bowl with your fish
2. Do NOT count the number of fish in the pond!
3. Have one member of your group remove a large handful of fish
4. Count the number of fish you just removed and write it in the table below
5. Replace these fish with “tagged” fish (in this case, colored “fish”)
6. Mix your pond well to redistribute the tagged fish among the other fish.
7.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)
8. Return your handful to the bowl!
9. Continue with this until you have taken 20 samples.
Data
Sample number
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. |
# of Tagged Fish in Sample
3 4 6 3 7 8 3 4 4 4 4 6 3 6 3 4 12 8 8 4 |
Total Sample Size
14 22 16 16 20 22 21 20 21 18 17 21 15 17 24 12 28 21 22 22 |
Percent Tagged in Sample
21% 18% 32% 19% 35% 36% 14% 20% 19% 22% 24% 21% 20% 35% 13% 33% 43% 38% 36% 18% |
Mean percentage tagged = 26.25%
Specific Analysis
1. The mean average of our percent tagged fish was 26.25%.
2. The estimated population of our pond was 95.
3. The number of fish actually in our bag was 120.
4. Our percent error was -22%.
5. This method does not appear to be an effective way to assess population size because the percent error was so large.
6. Concerns a biologist should have about this method is fish dying, and fish moving.
Conclusion
In conclusion, I decided that tagging is not an efficient way to go about assessing population size. The percent error was much higher than I had predicted it to be, and this process would be much more difficult in a real life setting. It's harder because fish, or any other animal, tend to move, die, etc. so there is no way that you could ever calculate the exact amount. This process makes it easier to get a general idea, but it is not accurate. In the article it explained how fishermen have to use a type of tracking to get a general idea, even if it's not as accurate sometimes, because it's their job to keep up with and record fish population sizes to show habitat quality.
Specific Analysis
1. The mean average of our percent tagged fish was 26.25%.
2. The estimated population of our pond was 95.
3. The number of fish actually in our bag was 120.
4. Our percent error was -22%.
5. This method does not appear to be an effective way to assess population size because the percent error was so large.
6. Concerns a biologist should have about this method is fish dying, and fish moving.
Conclusion
In conclusion, I decided that tagging is not an efficient way to go about assessing population size. The percent error was much higher than I had predicted it to be, and this process would be much more difficult in a real life setting. It's harder because fish, or any other animal, tend to move, die, etc. so there is no way that you could ever calculate the exact amount. This process makes it easier to get a general idea, but it is not accurate. In the article it explained how fishermen have to use a type of tracking to get a general idea, even if it's not as accurate sometimes, because it's their job to keep up with and record fish population sizes to show habitat quality.