To anyone who has spent a languid summer afternoon tumbling in the waves on South Beach or watched the earth’s closest star dip into the horizon at Menemsha, the ocean can seem eternal and unchanging. But scientists are increasingly discovering that human activity is transforming what was once thought to be an invulnerable resource. The ocean is getting warmer, more acidic, louder and filled with the detritus of civilization. What effect these changes will have on the ocean’s inhabitants in the decades to come is unclear.

Vineyard filmmaker Bob Nixon can’t escape great white sharks. Fresh from months of shooting the apex predators in the Pacific for a Discovery Channel special, last Tuesday afternoon he again encountered the animal, this time 100 feet off the Menemsha jetty. While the veracity of recent great white sightings on the Vineyard has been the subject of some debate, Mr. Nixon is fairly confident he saw the real deal. On board with him at the time was Dr. Sylvia Earle, one of the world’s preeminent oceanographers.

Tim Wakefield digs into a baseball just behind the horseshoe of the seams, a grip he credits to longtime Dodgers and Rangers knuckleballer Charlie Hough, one of only a handful of men in the major leagues who have been able to harness the sorcery of the pitch. In February, Mr. Wakefield retired after two decades hurling the strangest pitch in the game, a career that has led him to develop some unlikely skills.

Staring east from Chappaquiddick on a clear day, if you know where to look, a tiny white sliver peeks over the horizon. It’s the Nantucket water tower. Otherwise “the other island,” at only 12 miles away and barely over the curvature of the earth, might as well not exist to Vineyarders. And vice versa.