Texas Shark Rodeo & Sharkathon Measurement Rules & Diagrams

The most important part about collecting data from tagging and or collecting a fin clip is the accuracy of the data and the conformity of methods. The page was created to define and illustrate (bottom of page) the methods accepted by Sharkathon, Texas Shark Rodeo, Harte Research Institute, & TPWD.

Total length and fork length are to be taken utilizing a true linear measurement with no deflection of the measurement device during the process. Deflection of the measurement device is not an accepted method, do not follow any curvature of the shark, or deflect the measurement device over the shark’s body.

Total length is defined as a true linear measurement from the tip of the snout to the longest length of the upper lobe of the caudal fin (tail) when pushed down. Do not follow the contours of the shark, do not touch the shark with the measuring device. Hold the measuring device as close to the shark as possible while visually sighting an accurate measurement against the measuring device held in your hand.

Fork length is defined as a true linear measurement from the tip of the snout to the fork in the tail where the upper and lower lobes of the caudal fin come together. Do not follow the contours of the shark, do not touch the shark with the measuring device. Hold the measuring device as close to the shark as possible while visually sighting an accurate measurement against the measuring device held in your hand.

Girth length is defined as the circumference measurement of the widest part of the shark’s body typically between the pectoral and dorsal fins. Utilizing a flexible tape measuring device (a tailor’s tape works best) wrap it around the shark and once the tape overlaps you will have an accurate circumference measurement.

The 4’ aluminum ruler that is required to be placed within the photograph will allow a very accurate scaling of the pixels within the photograph allowing measurements to be established on a computer. This is why it is very important to familiarize yourself with the photo rules to make sure that you are taking photos as per our required methodology.

Failure to conform to these rules and or methodology can result in a submission being rejected. Read the rules, understand them and be properly prepared to obtain the required data in the quickest and most efficient manner possible to maintain the shark’s health during the process.