The 20 slick, mouse-gray blacktip reef sharks zipping through the waters at the National Aquarium look nothing like the bloodthirsty beasts of “Sharknado.” Two years old and only slightly longer than 2 feet, they’re toddlers — not much bigger than fat house cats.
Among sharks, these former residents of Australia’s Great Barrier Reef region are distinctive for their inky-tipped fins and tails. This summer, they arrived at their new home to play a unique role, one they will grow into over time: They are the stars of the Baltimore aquarium’s effort to re-create indoors an Indo-Pacific coral reef teeming with life.
In the new, permanent, $12.5 million, 13,500-square-foot Blacktip Reef exhibition, visitors will be able to watch these 11 female and nine male sharks mature. Over time, each will grow to as long as 5 feet. They will mate and, perhaps, bear pups of their own. Visitors can watch from high above, from just a few feet away from the water and through underwater windows as the sharks race dizzyingly close to more than 600 other fish. Cobalt-blue surgeonfish and dazzling diamondfish, among others, will glide around lumbering rays and become one with a “reef” that is, in fact, made of 3,000 pieces of painstakingly crafted man-made coral.
The 260,000-gallon indoor saltwater tank has, over the years, housed a dolphin exhibit and a parade of sea lions, beluga whales and rays. But Blacktip Reef is the first to match prey and predator in one highly fragile, underwater Gotham.
Coral reefs “are really like cities under the ocean,” curator Jack Cover said. “They cover 1 percent of the Earth’s surface, but at least half the fishes in the ocean will be found in them.” The aquarium has a separate “Atlantic Reef” exhibition that’s been going strong for more than a decade. But the population of Blacktip, like that of a real Indo-Pacific reef, is exponentially more diverse.
Because living coral is so crucial to the existence of so many fish, Cover said harvesting it and bringing it to Baltimore was out of the question. Instead, the staff spent 18 months constructing resin replicas of nearly 50 species of coral, then painting them the same burgundy, ochre, plummy purple and muddy russet you might see in the great deep.
The National Aquarium spent a substantial part of its budget repairing a leak in the concrete of the more than 30-year-old tank. A new floor-to-ceiling window looks deep into Blacktip Reef, which will serve as the centerpiece of the aquarium for years to come.
This snow-globe version of the Pacific is home to sharks, rays and hundreds of brightly hued bony fish culled from Australian and Indonesian waters. Peace in the underwater world, however, does not come easily. Imagine dumping several species at once into your own aquarium; under the best of circumstances, it’s messy. Now try it with an ornery little bugger known as the clown triggerfish; tiny, vulnerable blue-green chromi; a 518-pound sea turtle; and sharks whose diet consists of other fish.
The solution is a head-smacker: Aquarist Ashleigh Clews and others trained the shark pups and rays to seek out only bony fish and tender squid delivered by feeders. “They can be trained like a dog can,” Clews said. “They are very intelligent.”
But as the grand opening of Blacktip Reef inched closer, aquarists fretted that the sharks were not ready. The coral was in place, but only Calypso, the magnificent female green sea turtle who is one of the exhibit’s other big draws, would wade in by opening day.
When divers and other staff finally lowered sharks into the tank in a white-knuckled introduction process, it wasn’t without its run-ins. Calypso and her new roomies had a few “meet-and-greets,” Cover said with a nervous laugh.
If all goes well, time won’t wear away the shiny brilliance of this underwater city. Aquarium staff say they hope that the fish will adapt to the faux reef as if it were real and that the sharks will develop social circles.
The population of Blacktip Reef also will change as the aquarium adds more species.
“It’s been amazing to watch the fish settle in and see their natural behaviors,” Clews said. “Fish that I thought would stay a school didn’t, and fish I didn’t think would school are. It’s so fascinating every day to see what changes.”