Striped marlin (Tetrapturus audax)

The graceful body and prominent bill and dorsal fin of the striped marlin, along with its aerial acrobatics, provide an unforgettable thrill for anglers around the world. For this reason the striped marlin is of tremendous importance to coastal economies that are based around sport fishing.   Like all billfish species, the striped marlin population has been significantly reduced as a result of intense commercial and recreational fishing pressure.  Attempts are being made to conserve this species, but are hindered by the fact that the habitat preferences, movement patterns and stock structure of the world’s striped marlin are not well understood. 

The Offield Center for Billfish Studies (OCBS) is working towards gaining a better understanding of these fish and the environment they live in.  At OCBS, we are trying to answer questions concerning how changing ocean conditions are affecting striped marlin populations, if they travel long distance or tend to stay in a smaller area, and how are they are impacted by fisheries.

To answer these questions, OCBS has an active program focused on deployment of pop-up satellite tags on striped marlin off the coasts of Mexico, Ecuador, Australia, and New Zealand. A satellite popup tag is a data recorder that logs information while attached to a fish, and is programmed to release from the fish on a predetermined date. Once the tag has released it floats to the surface and transmits the data to a satellite. These tags record temperature, depth and light levels on a regular basis. From these data we can learn about the habitat use and behavior of the fish, as well as estimates of where the fish was traveling while carrying the tag.

Striped Marlin (Tetrapturus audax) with Satellite Pop-Up Tag

Since 2000 PIER/OCBS has put out over 100 pop-up satellite tags on striped marlin near Magdalena Bay, Baja California, Mexico. Our initial project focused on looking at survival of marlin that are caught and released in the recreational fishery. We are now focusing on the behavioral characteristics of striped marlin, including day and night activity differences, diving and migration patterns, as well as temperature preferences. 

Read more about Striped Marlin Mortality Study