Toothy Loiterers

I remember thinking, "so here they are" as I descended onto the Dixie Arrow. The details of the wreck were appearing, and slow, hovering forms were beginning to materialize all over it. I looked down in eager anticipation at the hordes of sandtiger sharks casually patrolling the ship's decks.

I grew up diving the wrecks off the North Carolina coast, but I never encountered the schools of sandtigers for which the wrecks are known. After years of living and diving in other places, I returned to my home waters to join NOAA's 2010 Battle of the Atlantic Expedition and dive into maritime history with archaeologists and biologists.

The Battle of the Atlantic expedition is an annual venture undertaken by marine scientists from NOAA's Monitor National Marine Sanctuary, East Carolina University and North Carolina's Coastal Studies Institute in order to explore, document and protect the cultural resources found on the bottom of the Atlantic. And there are many; during World War II, U-boats sank an astounding number of Allied ships, many just off the east coast of the United States. The remains of these vessels are now oases for many species of marine life, including the iconic sandtigers.

Sandtiger sharks (Carcharias taurus) are also known as sand sharks or ragged-tooth sharks and are closely related to Australia's grey nurse sharks. These sharks are found in temperate and tropical climates worldwide except in the eastern Pacific. They're generally regarded as harmless to humans, although a few unprovoked attacks have been reported. Sandtigers typically range in size from four to nine feet, with the largest individuals reaching 10 to 11 feet. They can be recognized by their second, large dorsal fin and a long mouth that extends behind the eyes, showcasing an impressive collection of pointed teeth. Many individuals have brown or reddish spots. Sandtigers are residents of many public aquariums due to their large size, fearsome appearance and resilience in captivity; individuals in aquariums have lived 16 years. Sandtigers feed on a wide variety of fish as well as rays, squid, crabs and lobsters.

I had dived with sharks many times before, but as we descended onto the Dixie Arrow, I realized this experience would be different than the others. The wreck was teeming with them. They swarmed over all 468 feet of it. I slowed my descent and leveled off at 70 feet near the top of the bow structure, 20 feet off the seafloor, and settled in among the big, poky beasts. I had finally come face to face with the most famous denizens of North Carolina's offshore wrecks.

My first impression of these gnarly looking creatures was that they were in no hurry. They seemed to glide about the structure with little in the way of an agenda. Based on the number of sharks and the scars some of them were sporting, it may have been mating season. The species is known to gather on wrecks in large numbers to mate, and gather they had. I tried to get an estimate of how many of the six- to eight-foot animals were loitering around, but lost count around 40. Not having dived the Dixie Arrow before, I didn't know whether this concentration of sandtigers was common or not, but it was certainly impressive.

The toothiness and placid nature of sandtigers are an unusual combination to find in a single animal. It makes them seem like something of a cross between a barracuda and a Jersey cow, or an Irish setter in dire need of dental work. It didn't take long to get comfortable with their presence; they hardly paid us any attention at all. At times they really didn't seem to be the most aware creatures in the ocean; I watched one cruise lazily into the fin kicks of a passing diver. The diver was swimming along about 10 feet in front of me, and the shark seemed oblivious of his presence. The diver never noticed the shark nudge his fins, but the shark reacted with a burst of energy. It spun 180 degrees and darted away, disappearing beyond the swirling cloud of ever-present baitfish. It was amusing to watch, and the first indication I'd observed that these sharks could move quickly.

The large and varied structural features of the Dixie Arrow allowed for interesting perspectives of the sandtigers. They circled ponderously around the high bow section, hanging 20 to 30 feet above the sand. When we began our trip across the low-lying debris of the 100-foot-long cargo hold, we shared the road with them as we made our way toward the stern. We looked over at their profiles as we swam past small groups of the sharks and got bird's-eye views of the ones that hugged the debris more closely. When we arrived at the boiler and engine area, we descended into a large, walled section of the wreck. It was here that sharing the space with the sandtigers was most interesting; they would rise up and over the walls or simply hang suspended in the middle of the open "room." Some circled the inner edge of the steel-bordered area while others drifted in from above.

Despite their docile sluggishness, they can be a bit menacing-looking, and the sheer biomass of shark hulking around the wreck was substantial. Each individual was pretty non-threatening, but the density of these snaggle-toothed fish could be a little unnerving every now and then. At the end of the dive it was reassuring to find out I wasn't the only one who was keenly aware of the sandtigers' presence at times during the dive. Upon breaking the surface, one of the archaeologists said with a wide-eyed grin, "Well. That was a lot of sharks."
Watch footage of the famed sandtigers of North Carolina's coastal wrecks.
Every since Mike Gerken started shooting underwater photography and video in 2003 he has strived to find a unique and diverse style of imagery that would appeal to a wide audience. His wreck photography from Truk Lagoon, Vanuatu and North Carolina has become well known in the industry for the stories the images tell while his marine photography with its simple but elegant composition has gained much notoriety in its own circles. He continues to seek out subject matter rich in color, texture and shape to capture the ocean's natural beauty. Presently, Mike is the captain of the dive vessel Midnight Express out of Morehead City, N.C. and can be found on any given day shooting the famous shipwrecks of the region as well as the prolific sandtiger shark population that inhabits them. To explore more of Mike's work visit http://www.evolutionunderwater.com/.
Bites & Attacks
Close Encounters of the Oceanic Kind
Cocos Islands 2010
Cooper River, South Carolina
Conserving Sharks
Diving in Behind the Scenes
Extinct for Soup?
Filming Great Whites
Growing Up Sharks
Man Meets Shark
Myths and Truths About Sharks
Shark Identification Quiz
Sharks of the Bahamas
Sharks of the Bahamas: The Slideshow
Shooting Great Whites
The Great White Shark Experience
Underwater Updates - Cape Town