Proper Way to Measure Fish

January 2, 2014

Question: What is the legal and proper way to measure a fish? Is it with an open mouth, closed mouth, fanned tail or pinched tail? I would appreciate some fish measuring guidelines to determine whether a catch is legal. Thank you.
(Rick B.)

Answer: The first rule when measuring fish is to lay the fish flat on its side and always pinch the mouth closed. Most saltwater fish with minimum size limits are measured to total length. This is the longest straight-line distance from the tip of the head to the end of the longest lobe of the tail (California Code of Regulations (CCR) Title 14, Section 1.62). The most accurate method is to place the fish's snout against a perpendicular surface and then measure along the intersecting horizontal surface to the end of the tail. Don't measure using a flexible "tape" over the fish itself or you will be given a longer, false reading.

There are some saltwater fish that are measured to fork length instead (for example, bonito, albacore, barracuda and yellowtail). Fork length is the straight-line distance from the tip of the head to the center of the tail fin (CCR Title 14, Section 1.62). So again, lay the fish flat on its side, pinch the mouth closed and take your measurement from the tip of the head to the center of the fork of the tail. These are the only two measurements that you will need to know for the purposes of the regulations when measuring whole fish. A measurement diagram for saltwater fish and shellfish is available in the ocean sport fishing regulations booklet and online.

All freshwater fish with a minimum size limit are measured to total length (CCR Title 14, Section 1.62).