To monitor and maintain a local wetland ecosystem, conservationists estimate the population of great crested newts (Triturus cristatus) using the capture-recapture method. In the first session, a sample of newts is captured, marked with a temporary non-toxic fluorescent skin dye, and released. In the second session, a new sample is captured, and the number of marked newts is recorded.
The population size is estimated using the formula:
population estimate=number in first sample×number in second samplenumber of marked animals in second sample \text{population estimate} = \frac{\text{number in first sample} \times \text{number in second sample}}{\text{number of marked animals in second sample}} population estimate=number of marked animals in second samplenumber in first sample×number in second sampleDuring the monitoring period, a significant portion of the dye washes off several of the marked newts before the second sample is collected, making them look completely unmarked.
What effect does this loss of dye have on the population estimate?
The population size is always overestimated.
The population size is always underestimated.
The population size remains unaffected.
The population size can be either underestimated or overestimated, depending on the sample size of the second capture.