Broadbill Swordfish

posted: 05/15/12
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Broadbill Swordfish
Ronald C. Modra/Sports Imagery/Getty Images |

In sportfishing heaven, an angler on a sundrenched, brilliant blue expanse of ocean wrestles with an automobile-sized broadbill swordfish. The broadbill, or Xiphias gladius, which is found in tropical, temperate and sometimes even cold waters in the Atlantic, Pacific and Indian oceans, is a powerful, aggressive and majestic-looking creature, and is perhaps the ultimate quarry in fishing. It's the true gladiator of the deep. It will fight an epic battle with a fisherman and often will win. In fact, you could fill volumes with "fish that got away" stories involving broadbills.

But the broadbill is also under pressure. Because it's a sportfishing prize as well as a popular food fish, it's a dying breed. Although consumers' fears of the fish's mercury content and government conservation efforts have helped the species, marine scientists don't yet have sufficient data to gauge its future prospects for survival.

The Gladiator of the Deep

If you had to design a fish with the perfect physique for brawling with an angler, it'd look something like a broadbill. In the Pacific, this burly, robust fish can grow to nearly 15 feet in length and 1.5 tons in weight. Its coloration is an undistinguished blackish-brown. But its size and the intimidating, saberlike protrusion on its head -- its bill -- set it apart.

The kingfish is the biggest of the mackerels, topping out at 5.5 feet in length and around 100 pounds, though on average, kingfish are closer to 20 inches and 20 pounds. It's a strikingly handsome fish, with an iridescent silver and iron-gray exterior and a mouth full of nasty-looking teeth. It differs from its cousin the Spanish mackerel in having a sharply dipping lateral line and a gray anterior dorsal fin instead of a black one.

The broadbill uses its bill to kill its prey, which include Atlantic mackerel, silver hake, redfish, herring and lanternfish, in addition to crustaceans and squid. The adult broadbill is preyed upon by killer whales. Its young are tempting meals for a variety of sharks, blue marlin, yellowfin tuna, dolphinfish and sailfish.

The broadbill primarily lives in ocean depths of 650 to 1,970 feet, though it's been observed swimming even deeper than that. It has an ingenious evolutionary adaptation: a bundle of highly vascularized tissue that provides heat to its brain when it descends into colder waters. Broadbills reach sexual maturity at five to six years of age and generally spawn year-round in equatorial waters and in the spring and summer in cooler regions. Its lifespan is about nine years.

Fish at Night and Troll Deep

The traditional method of fishing for broadbills has been to drift at night and set a range of baits at various depths, from 65 to 500 feet below the surface. Recently, though, fishermen have been trolling with a whole squid or tuna as bait, attached to breakaway sinkers or a downrigger. Use the strongest gear and line you can find, since the broadbill is tremendously strong. A broadbill's strike isn't quite what you might expect, given its size and power -- the reel will click slowly at first, and then increase as the broadbill picks up speed. The fish has a soft mouth, so hooks sometimes come unstuck, leaving you with another a great fish story and no fish. But if the hook sticks, be prepared for the fight of your life.

Why You Should Throw It Back

Because most fisherman can't reel in the biggest adults, they usually end up catching juveniles that haven't reproduced yet. This is not good news. You want to give the species a chance to replenish itself, which will help ensure that you and others can enjoy some epic fights with broadbills in the future. So if you catch a small one, release it.

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