Waterman's Journal

Nov 14, 2022

Species Profile: Blue Marlin

Blue Marlin: The King of The Sea

The blue marlin (Makaira Nigricans & Makaira Mazara) is the most revered and respected billfish. Highly regarded amongst offshore fishing enthusiasts for their memorable fights and incredible aerial displays, blue marlin are one of the ocean’s largest, fastest, and strongest predators. Known to reach weights of over 1,800 pounds and lengths of more than 16 feet, these billfish are at the apex of the ocean's ecosystem.

Where can you catch Blue Marlin?

Blue Marlin are highly migratory, with fish traveling across entire ocean basins and even between multiple oceans. Blue marlin can be caught all over the tropical and subtropical Atlantic Ocean. Meanwhile, on the Pacific Ocean, blue marlin can be caught from Mexico's Baja Peninsula through Peru with Hawaii being known as the big fish hotspot. Scientifically the same species, blue marlin are categorized by the main body of water they live in, hence the classifications of Atlantic and Pacific blue marlin.

A blue marlin makes a massive jump away from the boat. // Adrian Gray

How do you identify a Blue Marlin?

So how do you identify a blue marlin from the other billfishes? The back of the blue marlin is cobalt blue with white to silver flanks and belly. When excited or hunting vertical lines on its sides will become “Lit Up” turning electric blue. Its dorsal fin is high and pointed but is not taller than the depth of the fish's body. Unlike black marlin, the pectoral fins of the blue marlin are never rigid and can be folded completely flat against its sides for hydrodynamics when chasing prey or jumping high above the water's surface.

A wireman holds on tight to the leader for the final battle. // Brad Philipps

How do you tell the difference between a Blue Marlin and a Black Marlin?

Blue and black marlin are definitely two of the most sought after pelagic gamefish in the world. Both species are super aggressive apex predators that can grow to well over 1,000 pounds or more. To the casual observer, blue and black marlin look very similar, but there are several key differences that set apart the two species.

First of all, black marlin can be found only in the Pacific and Indian Oceans, and never found in the Atlantic. So if you catch a large marlin in the Atlantic ocean, it's not a black marlin. Generally speaking, black marlin can often be found hunting their prey in shallow nearshore waters (from 200 to 2000 feet deep), while blue marlin are found primarily offshore, in deep open waters far from land. The aforementioned fact that black marlin cannot fold in their pectoral fins and lastly blacks hold more weight in their shoulders and have larger heads.

A Blue Marlin brakes the surface in Kona, Hawaii.

How big do Blue Marlin get?

Like many pelagic bony fishes, blue marlin start out as microscopic larvae, no more than a few millimeters long. They grow quickly, and during their lives may increase their body weight by a million times over to reach “grander” status, which sport fishermen classify as a marlin of 1,000-plus-pounds. Like many migratory species, females are typically larger than males. In fact, adult female blue marlin are as much as four times the size of the largest males. The IGFA lists the All-Tackle (Atlantic) Blue Marlin record at 1,402 pounds caught off Vitoria, Brazil in 1992 by angler Paolo Roberto Amorim. However, much larger marlin have been landed, including the world’s largest known blue marlin to date – “Choy’s Monster”.

A marlin of literal monstrous proportions, 'Choy's Monster' claims fame as the largest of its kind at 1,805 pounds.

What do Blue Marlin eat?

Blue marlin feed on a wide variety of prey throughout their lifetimes. At a young age, they eat tiny zooplankton, and as they grow so does the prey they typically feast on. As adults, blue marlin will primarily eat bony fishes like tunas and mahi-mahi, as well as squids. There are few things that match watching a 50 lb Mahi Mahi being chased by a giant blue marlin.

A “Lit Up” blue marlin.

How do you catch Blue Marlin?

Blue marlin are caught by anglers using many techniques and fishing styles worldwide including live bait, trolled lures, and rigged dead baits on heavy tackle. Trolled lures were unpopular before 1954 when Captain George Parker caught the first ever grander blue marlin in Honolulu, Hawaii. His lucky lure was a handmade wooden tube with a silver skirt, one of the first of its kind. In modern times, the best tactic in any given region is trolling a spread of specific marlin lures in warm, offshore waters near banks or bottom contour curves and ledges with bait presence to entice a blue marlin bite.

The fight is over, a deckhand prepares to release a large blue marlin. // Carol Lynn

What kind of fishing tackle and gear is needed to catch Blue Marlin?

Blue marlin are much more aggressive and powerful predators than many other fish. If you are trying to catch a bucket list blue don’t go in under-gunned, a large marlin will take everything you’ve got to land. Here’s what is recommended as standard tackle for catching Blue Marlin:

● 6-7 foot conventional boat rod with XXH action with good backbone
● Strong conventional reel like a Shimano Tiagra 50 or 130 two-speed
● 100 to 130 pound braid or spectra backing
● 50 to 130 pound monofilament mainline
● 130 to 900 pound fluorocarbon leader
● 10/0 to 12/0 Owner hooks

A 700-lb. class blue takes flight! // Carol Lynne

Conclusion on Blue Marlin the Kings of The Sea.

Catching a blue marlin is an incredible experience that you’ll never forget. From setting up the perfect spread of lures to watching your bucket list fish explode on the surface, to the tackle and skill testing fight and then landing your trophy blue marlin; there are few experiences in sportfishing that even come close. - Hopefully, this article will help you to get one step closer to catching that elusive bucket list fish – the blue marlin - and tame one of the largest predators in the ocean.