The swordfish is a perciform fish found throughout the world, and instantly recognizable by its sizable upper jaw, which resembles a sword protruding from the front of the fish. It is popular for eating and sport, and the fish is caught all over the world along long migrations in search of prey. The conservation status of this fish is unclear, although several nations have noticed a decline in stocks and have closed swordfish nurseries to fishing as well as monitoring catches more closely.
In addition to the distinct upper jaw, swordfish also have crescent shaped rear fins and a tall front dorsal fin. The fish are generally gray blue to bronze on top, and pale cream on the bottom. They have streamlined bodies designed for rapid, efficient swimming, and are also extremely strong. They are voracious predators, eating a wide range of other fish species throughout the world's oceans. They have few predators as adults, other than humans, with the exception of some whale species.
Adult swordfish can reach lengths of 15 feet (5 meters) and weigh 1,400 pounds (650 kilograms) at maturity. Female swordfish tend to achieve larger sizes than males. In temperate areas, these fish spawn year round, temporarily pairing up with a partner to fertilize the eggs. In colder climates, spawning occurs in the spring and summer. The eggs float for several days before hatching into small larvae, which are often consumed by a number of larger fish. If allowed to grow, the fish will reach maturity in five to six years and can expect to live until approximately ten years of age.
The flesh of these fish is dense and white, well suited to grilling, baking, and saute. However, the flesh accumulates mercury at a high rate. As a result, consumers are not encouraged to eat swordfish and should limit their intake of the flesh to avoid bio-accumulation of mercury in their own tissues. Globally, sales and catches have declined since the 1970s, when the public was first alerted to the mercury risk.
Conservationists have raised concerns about these fish, as the majority of fish taken are young adults and juveniles. Because swordfish takes some time to mature, biologists suspected that excessive culling of juveniles might result in weaker stocks in years to come, and encouraged more controls on fisheries. In response, many nations enacted bans of fishing in known nursery areas, as well as size limits and more careful monitoring of on-board catches.