Among the artifacts that explorer John King collected on his travels around the world is an Aleutian headdress, supposed to conjure powers to hunt sea creatures.

It works. Twice a week, aboard the research vessel Aleutian Dream, King heads into the Atlantic waters off Cape Cod in pursuit of great white sharks. Once King locates the predators, he and the crew, which include shark expert Greg Skomal and researchers Cynthia Wigren and Meg Winton of the Atlantic White Shark Conservancy, use special equipment to tag and photograph them.

Since the expeditions began several years ago, 168 white sharks have been identified using the photographs and about 90 tagged. And the 2016 season isn’t even over yet.

An exhibit of photographs taken by King on these trips opens on Thursday, Sept. 1 at the Cape Cod Museum of Natural History at 869 Route 6A in Brewster. And at 1 p.m. on Saturday, Sept. 10, King will give a talk, “Shark-tember: Close Encounters of the Ocean Kind,” at the museum.

You might see the Aleutian Dream, accompanied by Wayne Davis’s spotter plane, travel past High Head in Truro or other Outer Cape waters in the next two weeks.

“We patrol from [Truro’s] Coast Guard Beach south to the hot spots around Monomoy and Chatham,” King says. “Once a week the plane surveys the whole Outer Cape, seeking sharks and gray seal haul-outs." One of the largest haul-outs identified in recent years is at High Head, but seal numbers seem lower this season, maybe due to water temperature changes, King surmises.

One of nine children, King is a Mayflower descendant whose family summered on the Cape, where he won competitions in a 17-foot, two-person sailboat. During his college years he drove West, camping and working in a cannery. After graduation he fished for shrimp and crab in stormy Alaskan waters for seven years, getting his master’s license at the age of 28.

Turned on to biotechnology by a fellow fisherman, King ended up CEO of various biotech companies over 25 years, selling his own Seattle-based genomics firm, Rosetta Inpharmatics, to Merck.

“I was known as the business guy who thought like a ship’s captain,” King says. Eventually quitting his job, he moved full-time to the Cape and settled in Chatham. His heart belongs to Cape waters, he says, where “so much of what’s going on, you can’t see.”

Shark activity, for one. King says that seeing a great white shark breach the waters to capture a seal in the documentary “Planet Earth” created a “cathartic shift” in his brain. “I had no idea this 2,500 lb. predator was so beautifully created. I became obsessed with seeing it.” After seeking white sharks on other continents, King was amazed when they turned up at home on the Cape.

“I was in Rio when I heard about [Skomal’s] first confirmed great white kill of a gray seal off of Provincetown, Labor Day, 2009. When I came back I sought out Greg to see how I could help.” To further involve himself with sharks, seals and whales, King became a board member of Provincetown’s Center for Coastal Studies. Three-and-a half years ago he helped Ben and Cynthia Wigren, founders of the AWSC, to organize and fundraise so that Skomal, who receives no state or federal money, could continue to research the Cape’s shark populations.

King also donated and re-fitted the Aleutian Dream, which he captains. His wife Pam is his first mate. The shark-hunting expeditions take place from mid-June to mid-October, and their protocols include photographing sharks from a Go-Pro on a 15-foot pole for the state Div. of Marine Fisheries’ John Chisholm to analyze in the lab.

“Each [shark] has their own distinct markings, definitive size, fin shape,” which, like whale flukes, mark them as individuals, King says.

The sharks are also tagged with acoustic devices that transmit specific radio signals for each shark. The signals are picked up by an array of buoys around the Cape, from the bay side to the ocean. The data from the buoys is downloaded intermittently and at season’s end.

In addition, five satellite-tagged sharks transmit data you can follow in real time on the Skarktivity app, where other shark sightings from citizens are vetted and transmitted quickly to hot spots to alert to swimmers and boaters. King says the five-year study being conducted aboard the Aleutian Dream should yield statistically accurate data on the numbers and sexes of white sharks visiting Cape waters. Current data puts the gender distribution at 52-percent male and 49-percent female. One-hundred-and sixty-eight sharks have been ID’d and about 90 tagged.

"The data for 2016 aren't in yet," King says. “We do know there are bigger numbers of sharks gathering now on the Outer Cape, further north than usual for this time of year.

“I love taking the boat to the Cape’s tip,” he adds. “It’s the most gorgeous landscape, especially in fall when the vegetation turns colors against the dunes. Seabirds come closer to shore, finbacks feed in the shallows. Gannets dive after bait driven in by tuna.”

King is also a co-founder, with his wife, of The Common Flat Project, a conservation organization dedicated to creating awareness of the importance of earth’s biodiversity, especially on Cape Cod. Copies of the Kings’ first book, “Wild Cape Cod: Free by Nature” (Schiffer Publishing, 2012) will be available at King’s lecture.