Fish Science Learning Modules

These are resources designed to teach the concepts of YPR (yield-per-recruit) and SPR (spawning potential ratio) and their applications to fishery management. The goal of this module is to provide an overview of the general concepts of YPR and SPR and how they can be used in fishery management. It is not designed to be an exhaustive description of YPR and SPR. Rather, it is aimed at audiences who lack formal fisheries science training, but are interested in better understanding the complicated fisheries concepts of YPR and SPR. 

1. Yield-per-recruit (YPR)

Does your fishery achieve high yields?

2. Spawning Potential Ratio (SPR)

Is your fishery ensuring population replenishment?

3. Growth overfishing

Are too many fish being harvested at small sizes?

4. Recruitment overfishing

What is the future outlook of your fishery?

5. Life history information

Which life history parameters are needed for YPR & SPR?

6. Size limits

How can a size limit help manage your fishery?

7. Setting size limits

Why should you consider both YPR & SPR when determining a minimum size limit?

8. Multi-species size limits

Considering size limits for a multi-species fishery?

9. Length-frequencies

What can length measurements tell us about your fishery?