Technically, L50 is the length at which 50% of the females of a particular species have reached reproductive size; essentially meaning that once a fish has reached it's L50 size it most likely has had a chance to spawn (i.e. make babies).  As such, it would also be true to say that a fish caught below its L50 size would most likely not have had a chance to reproduce.  Only catching fish that have grow to L50 size is one way to help ensure more fish on our reefsWe are hoping that these tools will provide fishermen and fish consumers with an opportunity to become familiar with these sizes.
Below you can find larger copies of the tools. Click on any of the photos to get a larger view.
You can pick up you own copy of the poster or the measurement guide at the offices of DEQ, CRM, DFW, NOAA, or at most of the local fishing stores.
The L50 Poster
![]()  | ||
The  poster shows some of the most commonly caught reef fish in the CNMI  painted to their L50 size, meaning that the full sized poster shows the  actual size at which it is thought the fish reach sexual maturity.  By  catching fish over this size, we can ensure that they have had a chance  to reproduce and replenish the reef before they are caught.
The L50 Brochure
The L50 Brochure
The  two sided, water proof brochure shows 22 of the most commonly caught  reef fish in the CNMI along with their L50 size written underneath in  inches.  The brochure also includes directions on how to measure your  caught fish using the built in ruler, as well as demarcates CNMIs marine  protected areas and details other relevant fishing laws in the NMI. 


