From the Chesapeake Bay to Panama, scores of Smithsonian divers probe underwater mysteries
The word "scuba" contains the name of an entire tropical island, so you might expect its origin to be at least a bit exotic. But no. Scuba dates from the early 1950s as a purely utilitarian acronym for "self-contained underwater breathing apparatus." Say "scuba diving" today, and for most people it's probably the recreational sport that comes first to mind. But scuba skills are essential to many professionals, such as oil-rig divers in the commercial sector. What may come as a surprise is that many Smithsonian researchers also need them.
The diving that occurs under Smithsonian auspices is called scientific diving. Its goal is to advance science through research underwater. The Smithsonian's Marine Science Network includes sites down the east coast of the continent, from the Chesapeake Bay in Maryland to locations in Florida and Belize, and on both the Atlantic and Pacific sides of Panama. The work performed at those sites—in marine ecology, geology, evolutionary biology and systematics (describing patterns of biodiversity in the sea)—has a cumulative authority born of decades of continual observation by Smithsonian researchers.
Marine biologist Michael A. Lang is director of the Marine Science Network, in addition to being, since 1990, the Smithsonian's scientific diving officer. He and his staff authorize about 180 scientists a year to dive with scuba equipment, but only after they complete a three-week course of instruction. The course includes lectures on physics, physiology and diving safety, a series of pool-based skills sessions, and a dozen supervised open-water dives in Key Largo or Panama. The progress of an individual's competence is precisely monitored, through distances that would be negligible in the surface world but are critical markers of safe passage underwater. A diver is cleared first to descend to 30 feet, and then, in stages, to depths of 60, 100, 130, 150 and 190 feet. The last is the maximum depth on compressed air permitted under Smithsonian practice, and only a dozen staff members have clearance to work so deep. Despite the postcard beauty of much scuba diving, the activity is not without risk, and the deeper the descent and the longer the time of submersion, the greater the need for caution. The principal danger is not the improbable giant squid or ravenous moray eel familiar to moviegoers but the debilitating effects of prolonged exposure underwater or a too-hasty ascent to the surface.
What draws scientists to the depths? A research agenda as spacious and varied as the environment they find there. They've observed, for example, how the highest sea-surface temperatures ever recorded, linked both to El Niño in 1997-98 and to global warming, induced the mass mortality of corals on lagoonal reefs in Belize; the coral loss, unprecedented in the past 3,000 years, justifies concerns about global climate change. But not all the news from down under is alarming. The first marine crustaceans with a social structure, three species of snapping shrimp, were recently discovered, and scientists now have an entirely new biological system in which to study advanced cooperative animal societies—aquatic competition for airborne bees and earthbound ants.
Scientific diving is not the same as the science of diving, but because advances in the second benefit the first, Michael Lang has taken a career-long interest in research on the physiological effects of diving. Typical concerns: How quickly should you ascend from various depths, and, if you're to dive both deep and shallow, in what order should you do the dives? In the 14 years Michael has been at the Smithsonian, some 600 scientific divers have logged more than 45,000 open-water scuba dives. In all those years, there has been but a single medical emergency among Smithsonian divers, and the incident had a happy resolution. Our scientists regularly slip from the bright familiar world to the dimmer one awaiting discovery beneath the waves. And time and again, buoyed by Michael's guidance, they come safely home.