Of all the marlin stocks currently assessed, white marlin are perhaps in the worst shape. For the past three decades or so, they’ve been severely overfished and, until 2011, were said to be experiencing overfishing. The International Commission for the Conservation of Atlantic Tunas has recorded the white marlin catch since 1956: Early on, total catches were minimal, but in 1965, those catches peaked at 5,000 tons. ICCAT has since capped the total white marlin catch at 400 tons for the entire Atlantic after the last ICCAT assessment for white marlin that was conducted in 2011.
However, there is significant skepticism whether current management measures are adequate to rebuild the white marlin stock. The next stock assessment for white marlin is slated for 2018, so we’ll have to wait a year to see whether things are improving.
That’s the science side of things for the entire Atlantic. However, if you talk to recreational anglers along the mid-Atlantic, they’ll probably tell you the white marlin fishing has been great for a while now and it’s only getting better. So how does one reconcile the seemingly disparate observations of the ICCAT scientific community and U.S. recreational anglers? Well, the National Marine Fisheries Service has actually aggressively managed billfish within federal waters for the past three decades. Some of the more-significant management measures have included:
• 1988: Prohibition on commercial harvest or sale of Atlantic billfish
• 1998: Size limits instituted for blue and white marlin
• 2000: Time/area closures to the Atlantic pelagic longline fleet
• 2000s-present: Increased voluntary use of circle hooks by recreational anglers, with mandatory use in billfish tournaments in 2007
• 2001: Recreational harvest capped at 250 white/blue marlin
• 2004: Required the Atlantic PLL fleet to use circle hooks
I was recently asked to give a presentation on U.S. billfish conservation measures for the Third Regional Workshop on Caribbean Billfish Management and Conservation, where IGFA and a group of other organizations are working toward developing enhanced billfish-management measures for the region. While assembling my presentation and outlining the aforementioned positive steps that the United States has taken for billfish, I reached out to my friend and colleague, Dr. John Graves, who has been chairman of the U.S. Advisory Committee to ICCAT for some 20-plus years. My questions were simple: Is there data that supports the observations of U.S. recreational anglers, and, if so, do you believe that domestic regulations might at least partially explain this. His response was also similarly simple: “Yes.”
Graves has been working closely with a number of premier white marlin tournaments for years and, among other things, has been tracking their catch-per-unit effort for tournament boats. He has been particularly involved with the popular MidAtlantic tournament and has shared data he’s been collecting since 1992. In this tournament alone, CPUE has steadily risen from 0.25 fish caught per boat per day in 1995 to a peak of 1.72 in 2016. That’s a pretty significant increase, and one not isolated to this particular tournament. Graves and one of his former graduate students reported in a peer-reviewed article in Fisheries Research that CPUE data from four major billfish tournaments with a primary target of white marlin had risen nearly fivefold since the late 1980s.
Want more evidence? Recently, NMFS released its annual Stock Assessment and Fisheries Evaluation report, which tallies the white marlin caught and released by the U.S. PLL fleet each year. Numbers have increased here as well, from 943 fish in 2011 to nearly 3,000 in 2016.
The take-home point here is that even though billfish are a highly migratory species that need to be managed at the international level by ICCAT, enhanced domestic and regional measures — like those put in place by the United States and those we are working toward in the different Caribbean nations — can make a real difference in some species. I say “some” because, unlike white marlin, blue marlin have not experienced the same increases in recreational CPUE and PLL release numbers. This might be explained in part by differences in migratory behavior. While both species get around a bit, white marlin typically don’t undertake the same trans-Atlantic migrations that blues do. As such, they might spend more time than blue marlin do within the Exclusive Economic Zone of the United States, where they are afforded enhanced conservation benefits from U.S. domestic regulations.