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.

- Describe the following from plots constructed with the data.frame that contains only Yellow Perch captured in fyke nets in 2005.
- The distribution of lengths.
- The distribution of weights.
- The relationship between weight and length.
- The relationship between the natural logs of weight and length.

- Describe the following from plots constructed with the data.frame that contains only Yellow Perch captured in 1998.
- The distribution of lengths separately for each gear (using only one command to make separate plots).
- The relationship between the natural logs of weight and length separately for each gear (using only one plot).
- The difference in mean lengths among the gears (plot should include confidence intervals).
- Describe the difference in numbers caught among the gears.

Save the script from this exercise as these data will be used in this weight-length relationship, size structure, and this condition exercise.

from Derek H. Ogle , created 08-Nov-15, updated 08-Nov-15, Comments/Suggestions.