However, the animal cruelty implications are not the only reason to stop this practice. Another major factor is that shark fisheries—and finning in particular—are having catastrophic effects on shark populations around the world. Approximately 100 million sharks are killed globally each year, and one of the major incentives for this is the shark fin trade. With their slow growth and low reproductive rates, sharks are highly susceptible to extinction, and it is difficult for many shark species to replenish their populations as quickly as they are being diminished. Many species of sharks are currently in danger due to shark finning, including the scalloped hammerhead, which is endangered, and the smooth hammerhead, which is vulnerable according to the International Union for the Conservation of Nature. Between 1.3 and 2.7 million of just these two sharks are killed every year in the shark fin trade, and the northwestern Atlantic population of the scalloped hammerhead declined from around 155,500 in 1981 to 26,500 in 2005. Today, some shark populations have decreased by 60-70% due to human shark fisheries.