Analyzing changes in fishery over time

Hi all!
I'm a rookie in statistics, but just wrapped up a semester of R analysis for natural resources. I'm working on my grad capstone and hoping I might be able to get some help generating ideas for worthwhile analysis to answer the following questions:

Changes in Run Timing
I don't have any effect for this question, but just wanting to show how the timing of the fish run has changed from the start of a project to current times. My data is based off of trapping.

Changes in fork lengths
I have fork length data for multiple rivers over a 15 year period. I wanted to examine how the lengths have changed over time, but also, lengths for hatchery v. wild fish.

Changes in Age Structure
Through field sampling, I have scale analysis results telling me the age structure of each year's spawners. Similar to fork lengths, how has this changed over time, and specifically, between wild and hatchery fish.

Any help is much appreciated! Just looking for some ideas because while I really enjoyed ANOVA/regression analysis, I'm sure there are some much better ideas for these questions.