When you study aquatic animals, you need to be where they are. Over the past five years, John Sparks, curator in the Museum’s Department of Ichthyology, has descended on numerous submersible dives to study bioluminescence and bioflourescence in marine fishes and invertebrates. Sparks, who oversaw the special exhibition Unseen Oceans, recently shared what it takes to go deep.
Dress to Dive
In the tropics, it’s shorts and a T-shirt. “At the surface, it’s hot because you’re inside an acrylic ball in the Sun. It’s like being under a magnifying glass,” says Sparks.
Pop, Pop
Much like take-off and landing in an airplane, your ears pop when the hatch is sealed and the sub is pressurized. On the way down, sights include schools of anchovies, jellyfish, ctenophores, and squid, which “welcome” the sub by covering the windows with ink: “It’s amazing how much ink they produce,” says Sparks
Mid-Sea Critters
On the way down, sights include schools of anchovies, jellyfish, ctenophores, and squid, which “welcome” the sub by covering the windows with ink: “It’s amazing how much ink they produce,” says Sparks.
Lights Out
As the submersible descends, light appears as a small circle—an optical phenomenon known as “Snell’s window.” At 300 to 450 meters below the surface in clear ocean water, there is very little remaining light, if any, from the surface.
Night Vision
“When you get down several hundred meters, the current diminishes, and it’s frequently crystal clear,” explains Sparks. “You can see a variety of bizarre deep-sea fishes close up and sit on the bottom with lights out and observe.”
Tight Fit
Legroom in the rounded sub cabin is tighter than on your typical airline flight, so a 6- to 8-hour dive can feel cramped.
No Leaks
Feel a drop of water? Don’t panic. That’s just condensation from passengers’ breath, which collects on the dome ceiling.
A partial replica of a Triton submersible is on view in Unseen Oceans.
A version of this story originally appeared in the Spring 2018 issue of Rotunda, the Member magazine.