After decades of fishing, the dusky shark is now a species on the brink.
The dusky shark gives birth only once every three years after reaching sexual maturation at the age of 20, meaning it has one of the lowest reproductive potentials among all sharks. A low reproductive rate makes the dusky shark especially vulnerable to exploitation by fishermen who pursued the shark for its meat, skin, liver, and fins for decades. In fact, the dusky shark is one of the most sought-after species in the shark fin trade. Dusky sharks continue to be threatened by commercial fishing that targets swordfish and tuna but that catch sharks as well (known as bycatch). Once hooked, most dusky sharks die before they can be released. As a result of these threats, the northwest Atlantic dusky shark population, which lives primarily in U.S. waters, has dropped to between 15 and 20 percent of its 1970 level (scientists know much less about the status of dusky shark populations in other parts of the world).