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IGFA Great Marlin Race provides important tag data to scientists around the world

By BY DONNELL TATE/Harbor Report - | May 14, 2021

Billfish tagged during the Great Marlin Race provide data on their movements via high-tech tags. PHOTO BY THE IGFA.

The IGFA Great Marlin Race, presented by Costa, is a partnership between the International Game Fish Association and Stanford University that links recreational anglers with advanced satellite tagging technology to study the ecology of billfish species worldwide. With the health of many billfish stocks in question across the globe, the IGMR seeks to obtain the information necessary to better inform resource managers and policymakers to ensure long-term sustainability of these recreationally and economically important species.

The IGMR has three primary goals: increase understanding of the distribution and behavior of billfish species in relation to their environment in order to better inform fishery-management entities; increase participation of recreational billfish anglers worldwide in electronic tagging science; and to provide free, open-access billfish tag data to scientists throughout the world for their research.

The concept of the IGMR is simple: during billfish tournaments, angling teams are invited to sponsor pop-up satellite archival tags to be deployed on marlin, sailfish or spearfish species caught and released during the event. Then, 240 days after the PSAT is deployed, it automatically releases itself from the fish and transmits information of its migratory path, depth profiles, and sea temperatures to Earth-orbiting Argos satellites, which is then sent to researchers at Dr. Barbara Block’s lab at Stanford University to be compiled, processed and analyzed.

Because the total logged distance is estimated using advanced geolocation algorithms with some error, the IGMR uses straight-line GPS distance from deployment to tag release to judge the IGMR winners. Essentially, the PSAT that pops up farthest away from where it was deployed wins the race. Since the program started in 2011, the IGMR has become the largest citizen science- based billfish satellite-tagging program on Earth.

To date, the IGMR has deployed over 440 satellite tags on seven species of billfish in 21 different countries around the world. These IGMR tags have collected nearly 250,000 miles of billfish-tracking information. To put that into perspective, tagged billfish have traveled enough miles to circumnavigate the Earth more than 15 times.

The IGMR plans to deploy up to 40 PSATs on marlin, sailfish and spearfish in 2021. Deployment locations include the Bahamas, Bermuda, California, Hawaii, Italy, Japan, New Zealand, Tobago and Western Australia. They are excited to add even more data to the IGFA Great Marlin Race database in regions where little is known about billfish biology and behavior.

The IGMR has also been successful at advancing billfish science and management. Data from the IGMR represents the world’s largest billfish satellite-tagging database, and this information is made freely available to the scientific community for analysis.

Because of this open access data policy, the IGMR has contributed to eight peer reviewed scientific articles, with more currently in progress. This dataset was also used to accomplish perhaps the most important billfish legislation in U.S. history: the Billfish Conservation Act of 2012.

In coordination with Wild Oceans, whose mission is to “keep the oceans wild to preserve fishing opportunities for the future,” the IGFA was successful in obtaining the passage of this act, as well as a subsequent amendment in 2018. This legislation effectively bans the importation of marlin, sailfish and spearfish in the continental U.S. and substantially reduces the global market for these threatened species.