## Example #1

Suppose that a researcher captured and individually marked 75 fish on day 1. Two days later, a total of 100 fish were captured of which 25 were marked.

- How many columns are in the capture history matrix?
- How many rows are in the capture history matrix?
- What does a row for an individual fish in the capture history look like for …
- A fish captured in both samples?
- A fish captured in the first but not the second sample?
- A fish captured in the second but not the first sample?
- A fish captured in neither sample?

## Example #2

A researcher sampled a stream weekly for 8 weeks.

- How many columns are in the capture history matrix?
- How many rows are in the capture history matrix?
- What does a row for an individual fish in the capture history look like for …
- A fish marked in week 2 and recaptured in weeks 7 & 8?
- marked in week 3 and then not seen again?
- marked in the first week, captured again in week 3, and captured again in week 5, but not again?

## Example #3

Use the following summary of capture histories to answer the questions further below.

Capture History 001 010 011 100 101 110 111 Frequency of fish 17 20 4 19 5 8 2

- How many capture events were used?
- How many total fish were captured?
- How many fish were captured in the first sample and then not seen again?
- How many fish were captured in the first sample and seen again?
- How many fish were captured in the first sample?
- How many fish were captured in the third sample?
- How many fish in the second sample were recaptures (i.e., previously marked)?
- How many fish in the third sample were recaptures?
- How many fish were captured exactly twice?
- How many fish were never captured?