2019 Conservation Record: Black Marlin

Courtesy of Stuart Simpson

The Billfish Foundation maintains the largest private tag and release database in the world, with over 260,000 records. In 2019 alone, over 11,000 new tag, release, and recapture records were added to this database, representing an enormous amount of data to help us learn more about billfish life history. Of these over 11,000 new records in 2019, 502 were of black marlin, including one black marlin recapture. 66% of black marlin were released without tags, while 34% were tagged. To learn more about how to identify a black marlin, check out our youtube channel!

Tags*

A total of 172 black marlin were tagged in 2019. 131 black marlin were tagged in the Pacific, 41 were tagged in the Indian, and none were tagged in the Atlantic, as they do not live there. The average estimated weight for tagged black marlin was 172.4lbs (78.2kg), though they ranged from 30lbs (13.6kg) to 900lbs (408kg).

Top: Black Marlin tagged in 2019. Color denotes the estimated weight of fish, Bottom: Black Marlin tagging density in 2019. Warmer colors denote higher tagging densities. Number of fish tagged per location denoted in white.

96 total anglers and 21 captains tagged black marlin in 2019. The majority of the tagging effort was shouldered by Captains Tim Richardson, Craig Denham, and Ross Newton out of Australia. In fact, the majority of black marlin, 146 total, were tagged near Australia. However, tags were also deployed in the Seychelles, El Salvador, Costa Rica, Mexico, Panama, and Japan. 19 black marlin were tagged in the Seychelles, and five were tagged in Latin America. The remaining two were tagged off of Japan and Mexico (not mapped).

The majority of black marlin tagging effort occurred during during the Winter and Fall seasons. Peaks occurred in January and October, then trailed off. Almost no black marlin were tagged during the summer.

Releases*

330 black marlin were released without tags in 2019, nearly double the number that were tagged. Of these, 139 were released in the Pacific Ocean and 191 were released in the Indian Ocean. 55 anglers and 19 captains released black marlin for TBF this year, the majority of which were released by Captains Eddy Lawler, Brett Alty, and Craig Denham.

The majority of black marlin were caught and released near Australia. In fact, 314 of the 330 black marlin were released offshore of Australia. Also, only in Australia were three or more black marlin released in one location in one day.

Black marlin released in 2019 near Australia. Colors based on number of black marlin released in that location on that day. Please note that all fish were released in the ocean, despite the symbols occasionally appearing to overlap with the land.

The remaining 16 black marlin releases occurred offshore of Central America and East Africa. More specifically, black marlin were released offshore of Costa Rica, Kenya, Panama, and the Seychelles.

Black marlin released in 2019 near Australia. Please note that some points overlap and are less visible.

Similar to tags, black marlin catch and release rates took a steep decline during the summer months. However, unlike tagging, more black marlin were released without tags in the spring than any other season, with May containing the highest number of releases by 30 fish. Also opposite to tags, the fall and early winter showed low release rates, which picked up in January.

Recaptures*

One black marlin was recaptured in 2019. This black marlin was originally tagged on October 6th, 2016 near Ribbon Reef #4 in Australia’s Great Barrier Reef by Captain Craig Denham, first and second mates Tamara Thompson and Jimmy Gigger, and angler Paddy Gallagher aboard Hot Shot. The fish was at large for 856 days (roughly 2.3 years), before it was recaptured near Fiji on February 9th, 2019 by angler Isikelo Tavo aboard Solander X. In that time, the fish had traveled, at minimum, 2,226.92 miles (3,583.88 kilometers). This recapture was only TBF’s 29th black marlin recapture since the inception of our program in 1990, meaning that the information that we gained from it was extraordinarily rare and valuable.

An enormous thank you to all of the captains, mates, and anglers that tagged and released black marlin for TBF in 2019. Black marlin are an incredible species whose habits we have not yet elucidated. Only through your active participation can we hope to learn more about black marlin and, as a result, conserve them for years to come.

To stay up to date on all things billfish, become a member, subscribe to our newsletter, and follow us on social media, @TheBillfishFoundation. To learn more about tagging and how you can get involved, check out our website. To purchase tagging equipment and other TBF items, check out our online store.

*Please note that this review includes only black marlin that were tagged, released, and/or recaptured between 1/1/2019 and 12/31/2019 and whose records were received by TBF by 1/15/2019