Something's Fishy...
Purpose: To be able to estimate the sizes of the same population of fishes, using the make-recapture technique. Estimate the number of organism living depending not eh number of species capture that were tagged already.
Background: Sampling: technique used to estimate population size. Organisms in a few small areas are counted and projected to the entire area. Scientist can predict the amount of species living in that area. Another method in determining populations of a variety of species biologists use is called tagging. The purpose of these tags is to track migration patterns, health, and range as well as to help determine population numbers of species in an area. Determination of population occurs by capturing and tagging that sample of animals. Biologists would then release the
animals and allow them to naturally “redistribute themselves.” By then taking random samples and determining the percent tagged, biologists are able to hypothesize the population of that species in that area
Procedure:
There’s going to be to bowls of the specie. One gold, the other on with different colors. Color crackers = tagged fish.
1. Grab a handful the “species” (fish = crackers) that are gold.
2. Count the number that were caught.
3. Replace them with the same amount of crackers with the ones of different color. Number that were change; 35.
4. Mix pond with the tagged fish among the other fish (Gold and color.)
5. One member at a time (and without looking), remove a handful of fish and record the number of total.
6. fish in the sample, the number of “tagged fish”, and figure out the percentage of tagged fish. (see chart)
7. Return the fishes 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?
42%
2. Using the following formula, determine an estimated population for your pond:
Population Size = total number captured x number marked (line #3 above)
total number captured with mark
536 * 36 / 216 = 89..33 or 89
3. Now, actually count the number of fish in your bowl: 102 fish
4. Find your percentage error by using the following formula:
100 x (Your estimate of population - Actual size of population) / (Actual size of population)
100 * 86 - 102/102 = 83%
5. What concerns should a biologist have about a species’ habits before (s)he uses this method to approximate the size of a population?
The number of species that immigrates, and emigrates. Their reproduction rate, and how many birds are made each year. Also what can be some causes of decrease: weather, # of predators.
Conclusion: How did you fulfill the purpose? What did you learn?
I was able to fulfill the purpose by using the using different kind of fishes form different colors, that were the tagged fishes. We mixed them with the gold ones and then tried to capture them. We repeated this 20 times, and calculated the total of fish that were tagged with the ones that weren’t. Then putted them back. What I learned was that we will be able to capture the same fished we caught before, in different groups and maybe more than ones. Also that there’s not a exact answer to how many species can there be. This because some of the crackers fell, or they crumbled, this means we lost some fishes. Though it’s not a precisely method it can always give you a close answer that we can use.
Background: Sampling: technique used to estimate population size. Organisms in a few small areas are counted and projected to the entire area. Scientist can predict the amount of species living in that area. Another method in determining populations of a variety of species biologists use is called tagging. The purpose of these tags is to track migration patterns, health, and range as well as to help determine population numbers of species in an area. Determination of population occurs by capturing and tagging that sample of animals. Biologists would then release the
animals and allow them to naturally “redistribute themselves.” By then taking random samples and determining the percent tagged, biologists are able to hypothesize the population of that species in that area
Procedure:
There’s going to be to bowls of the specie. One gold, the other on with different colors. Color crackers = tagged fish.
1. Grab a handful the “species” (fish = crackers) that are gold.
2. Count the number that were caught.
3. Replace them with the same amount of crackers with the ones of different color. Number that were change; 35.
4. Mix pond with the tagged fish among the other fish (Gold and color.)
5. One member at a time (and without looking), remove a handful of fish and record the number of total.
6. fish in the sample, the number of “tagged fish”, and figure out the percentage of tagged fish. (see chart)
7. Return the fishes 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?
42%
2. Using the following formula, determine an estimated population for your pond:
Population Size = total number captured x number marked (line #3 above)
total number captured with mark
536 * 36 / 216 = 89..33 or 89
3. Now, actually count the number of fish in your bowl: 102 fish
4. Find your percentage error by using the following formula:
100 x (Your estimate of population - Actual size of population) / (Actual size of population)
100 * 86 - 102/102 = 83%
5. What concerns should a biologist have about a species’ habits before (s)he uses this method to approximate the size of a population?
The number of species that immigrates, and emigrates. Their reproduction rate, and how many birds are made each year. Also what can be some causes of decrease: weather, # of predators.
Conclusion: How did you fulfill the purpose? What did you learn?
I was able to fulfill the purpose by using the using different kind of fishes form different colors, that were the tagged fishes. We mixed them with the gold ones and then tried to capture them. We repeated this 20 times, and calculated the total of fish that were tagged with the ones that weren’t. Then putted them back. What I learned was that we will be able to capture the same fished we caught before, in different groups and maybe more than ones. Also that there’s not a exact answer to how many species can there be. This because some of the crackers fell, or they crumbled, this means we lost some fishes. Though it’s not a precisely method it can always give you a close answer that we can use.