Thursday 1 October 2015

The Fate of the Hammerhead Shark

Continuous shark finning is an immediate problem for sharks. In recent years the hammerhead shark family is continuously threatened to the extent that the scalloped hammerhead sharks in particular are now officially a part of the endangered species list.

Source: PRETOMA
As seen in Figure 1, scalloped hammerhead sharks are threatened if not endangered in almost all parts of the ocean. Because the sharks have a normal migratory path, fishers prey on them at specific locations quickly reducing the numbers with each catch. As seen in Figure 2, the exploitation rate exceeds the rebound rate thus making the growth rate reflect how the sharks cannot reproduce and grow fast enough to keep up with the constant shark finning. The lack of time needed to reproduce results in the eventual extinction of the species unless the culture of shark finning changes.

Figure 1. Source: NOAA

Figure 2. Source: Boris Worma, et al. "Global catches, exploitation rates, and rebuilding options for sharks"