Ugly River Brown Trout

Young and Hayes (2001) described a study where Brown Trout (Salmo trutta) in several rivers were captured by experienced fly fishers, tagged at the base of the dorsal fin with a colored dart tag, and then observed by divers drifting through the sample area two days later. In this study, 43 trout were marked, 123 fish were observed by the divers, and 16 fish observed by the divers were tagged.

  1. Assign one of these symbols (N, M, n, m) to each of the numerical results from this study.
  2. Construct a population estimate, with 95% confidence interval, for the Brown Trout in this section of the Ugly River. Carefully interpret the results.
  3. How does your result compare to the result shown in Table 1 of Young and Hayes (2001)?
  4. Which method did you use to construct the confidence interval? Explain why you chose that method.

 

Upper Niagara Springs Pond Rainbow Trout

Warren et al. (2004) examined the population of Rainbow Trout (Oncorhynchus mykiss) in the Upper Niagara Springs Pond in 2000. Fish were captured at two times by using an electrofishing unit attached to a driftboat. The capture history of all fish examined in the two samples that were 100 mm and longer is in RBTroundUNSP.csv (data, meta). Analyze these capture histories to answer the following questions.

  1. Create a summary of the capture histories. [Hint: Use capHistSum() from the FSA package.] Explain what each value in the summary means.
  2. From your capture history summary assign values to each of M, n, and m.
  3. Construct an appropriate population estimate, with a 95% confidence interval, for Upper Niagara Springs Pond Rainbow Trout in 2000. Carefully interpret the results.
  4. How does your result compare to the result shown in Table 10 of Warren et al. (2004)?
  5. Which method did you use to construct the confidence interval? Explain why you chose that method.