A shortfin mako glides through the waters off the coast of California in this image captured by National Geographic photojournalist Brian Skerry.

For nearly 30 years, Skerry has been swimming with and photographing sharks, including great whites, tigers, bulls, blacktips, and great hammerheads all around the world. In his first blog post for the Smithsonian Ocean Portal, "Swimming with Sharks," Skerry reflects on these exhilarating experiences.

The shortfin mako shark (Isurus oxyrinchus) is found offshore in tropical and warm temperate waters of all oceans, but has been known to travel to cooler waters at times. It is very strong and the fastest known species of shark. These qualities make the shortfin mako a prized catch among recreational fisherman. The mako is also sought by commercial fisheries for the production of shark fin soup, leather, and oils, and is often caught unintentionally as bycatch. These fishing pressures have led the International Union for the Conservation of Nature to list the shortfin mako shark's status as "Vulnerable."