Researchers for the North Temperate Lakes Long-Term Ecological Research program have collected fish from a number of lakes in Wisconsin since 1981. The total lengths and weights of Yellow Perch (Perca flavescens) captured from Trout Lake from 1981-2006 are recorded in YPerchTL.csv (view, download, meta). Use these data to answer the following questions. [Note that these data came from this website. See the site for more information about the sampling protocol that produced these data.]

Complete this Data Manipulation exercise to create the required data.frames used in the following questions.

1. Describe the distribution of lengths for Yellow Perch captured in fyke nets in 2005 using both a histogram and frequency table with 10 mm length categories.

2. Statistically compare the length frequency distributions between Yellow Perch captured with a beach seine and in fyke nets in 1998.

3. Use the data.frame for Yellow Perch captured in 1998 (from all gears combined).
1. Compute the $$PSD-Q$$ value (with 95% confidence interval).
2. Compute the $$PSD-P$$ value (with 95% confidence interval).
3. What assumption must be made for these calculations to have a useful biological meaning.

from Derek H. Ogle , created 21-Jan-16, updated 23-Jun-16, Comments/Suggestions.