Bio 103 Lab - Lab 8. Ecology
EXPERIMENT 1: How many fish were tagged with blue tags in the initial marking session?
100
EXPERIMENT 1: Calculate the population estimate (N) for the initial bluegill population using the equation: N=M(n/m) where Mis the number of marked individuals in the first sample; N is the total population size; m is the number of marked individuals in the second, or recaptured, sample; and n is the total number of individuals in the second, or recaptured, sample.
1000
EXPERIMENT 2: How many fish with red tags were recovered from the second mark and recapture experiment?
13
EXPERIMENT 2: What are the average length and mass, respectively, for the second marked bluegill population?
15.7 cm and 481.931 g
EXPERIMENT 1: What are the average length and mass, respectively, for the initial recaptured bluegill population?
19.2 cm and 445.763 g
EXPERIMENT 1: What is the mass/length ratio of the initial marked bluegill population? The mass/length ratio is determined by dividing the average mass of the population by the average length.
24.9
EXPERIMENT 2: Calculate the population estimate (N) for the bluegill population after predators were introduced using the equation: N=M(n/m) where M is the number of marked individuals in the first sample; N is the total population size; m is the number of marked individuals in the second, or recaptured, sample; and n is the total number of individuals in the second, or recaptured, sample.
769
CONCLUSIONS: Which of the following is NOT another environmental factor that could affect the bluegill population in the sample lake?
The bluegill's competitor goes extinct in a nearby lake.
CONCLUSIONS: Based on the assumptions described in the introduction why might the mark and recapture method of population estimation be more accurate in the lake setting we are studying than in a stream or river?
The fish would not be able to leave the lake sampling area, whereas in a stream or river they can go upstream or downstream of the sampling area.
CONCLUSIONS: What effect did the introduction of the predators have on the bluegill population? Was the hypothesis in the introduction correct?
The population size decreased; the hypothesis was correct.