The broadbill swordfish may very well be one of the toughest creatures found in the deep. Swordfish are pure muscle. They're shaped almost like a cigar butt -- thick all the way through with a very powerful, crescent-shaped tail capable of lightning-quick bursts of speed.
Swordfish (Xiphias gladius) are aggressive and pugnacious by nature. Throughout the annals of maritime lore, many a tale has been spun about giant swordfish attacking and even puncturing boats. According to the IGFA, a swordfish attacked Alvin, a research submarine operated by Wood's Hole Oceanographic Institute, at a depth of 330 fathoms. The fish wedged its sword so tightly into a seam of the vessel that it could not be withdrawn. Modern-day technology has caught some of this behavior on video as swordfish went after offshore drilling equipment.
Because of their strength, size, fight and the difficulty involved in catching one, swordfish are held in very high regard by offshore anglers. While most swordfish average between 60 and 200 pounds, they are capable of growing upwards of half a ton. The IGFA all-tackle world record stands at 1,182 pounds, a true beast caught by Louis Marron in 1953 off of Chile. These very large swords are always females, as males rarely exceed 200 pounds.
Because swordfish meat is so desirable, swordfish are very susceptible to overfishing. In the 1990s, North Atlantic swordfish populations dwindled to about 60 percent of target levels. A number of conservation efforts went into effect to turn around swordfish stocks. The outlawing of longliners in the Florida Straits is just one measure that has helped this species turn the corner and reignited a sport fishery up and down the East Coast, as well as in the Gulf of Mexico and Caribbean.
Recreational fishing boats target swords both day and night using a range of techniques. In the nighttime hours, the swords hunt higher in the water column, although sometimes they are found basking on the surface during the daytime as the warmer waters help them digest their food. Swordfish have developed unique adaptations to aid them in search of prey, such as special eye muscles and a heat exchange system that allow them to swim into deep, cold waters. Swordfish eat a range of prey, and bonito bellies, strip baits and squid are some of the most popular baits used by recreational anglers. Hooking swordfish can be tough because they have a soft mouth and will oftentimes slash at a bait before attempting to swallow it.
While often referred to as a "billfish," swordfish are not in the same family as marlin. Swordfish have a long, flattened bill that's shaped much like a sword, as their "broadbill" nickname implies. A marlin's bill is more round in shape. Swordfish have large eyes to help them hunt in the dark. The sword has a non-retractable dorsal fin and rigid, non-retractable pectoral fins. The coloring of the fish can differ greatly depending on whether you catch it during the day or at night. The back can range from dark brown to bronze to even purple, while the belly is typically white or a golden tan.
Swordfish are found around the world in tropical, temperate, and sometimes cold waters of the Atlantic, Indian and Pacific Oceans. North Atlantic swordfish are found in the Gulf Stream of the western North Atlantic Ocean, extending north into the Grand Banks of Newfoundland. North Atlantic swordfish are also found in the eastern Atlantic along the coast of Africa and Europe. North Atlantic swordfish annually migrate thousands of miles along the eastern seaboard of the United States and Canada and also in the eastern Atlantic along Africa and Europe.
Swordfish live at the surface to mid-water depths, but feed throughout the water column, and they will migrate annually from spawning grounds in warm waters to feeding grounds in colder waters. The Gulf of Mexico is an important nursery area for North Atlantic swordfish. In the western North Atlantic they spawn south of the Sargasso Sea and in the upper Caribbean from December to March and off the southeast coast of the United States from April through August. Swordfish can live to about 9 years.
New Zealand is also one of the best-known areas to target swordfish. Famed writer and fisherman Zane Grey helped bring notoriety to this nation as he chronicled his search for swords and other big fish in his book, Tales of the Anglers Eldorado, New Zealand. The deep waters off the North Island remains one of the best spots in the world to target big swords. Other notable hot spots include Kenya and Venezuela. Hopefully, more areas will become swordfish hot spots if the species is given more time to rebuild after decades of overfishing.