If it’s been a while since your last visit to the St. Lucie County Aquarium, you might want to consider making the trek. New residents have moved into the deepwater Oculina Banks exhibit. New digital frames are posted near each tank. And the coral reef is celebrating one year being in a bigger, better – and non-leaky – tank.
The Oculina Banks ecosystem exhibit has added six new fish along with several new Oculina varicosa skeletons, which will serve as hiding spaces for the newcomers. They will be contending with the exhibit’s large predator – a Short Bigeye.
“It’s important to us to showcase that diversity,” said Bill Hoffman, director of the aquarium. The Oculina reef is a unique habitat found only off the east coast of Florida in waters that range from 200 to 300 feet deep. The reef stretches from Fort Pierce north to St. Augustine and sits between 20 and 40 miles offshore.
“In a soccer ball-sized area of the ivory tree coral, researchers found nearly 500 organisms,” the aquarium said in a prepared statement about the Oculina exhibit’s facelift and new residents.
The Oculina exhibit is 18 years old, Hoffman said, dating back to when Harbor Branch still did submersible diving, collecting deepwater specimens. The Oculina exhibit has been home to several such specimens. “They don’t live forever,” Hoffman noted.
For some time, Hoffman has been trying to acquire more animals to add to the Oculina tank, but the prohibitive expense of sending a diver to collect them kept the goal from being accomplished. He explained that one collection company would have charged $3,200 for a dive; the aquarium could keep anything and everything collected. However, if the dive team came back empty-handed, so, too, would the aquarium.
“That’s just the risk,” Hoffman.
Instead, he has been calling a few times a year in the hope that another collector had what he was looking for. Recently, the aquarium’s luck turned and Hoffman was able to get the six fish for the Oculina tank at “bargain basement prices,” he said, explaining that five cost $250 each while the sixth was $500. They retail for a tremendous amount more, he said.
But it wasn’t as simple as plopping the new fish into the established tank – they would have quickly been eaten by the Short Bigeye.
Instead, Hoffman pulled the Short Bigeye out, temporarily rehoming it elsewhere in the aquarium. He then introduced the Red Hogfish, the two Rough Tongue Bass, and the three Red Barbiers into the exhibit. Every so often, he’d dunk his hand into the tank and agitate the fish – forcing them to flee for cover, using the Oculina skeletons.
Doing so, the fish became accustomed to their preferred routes of escape to safety.
Hoffman then brought the Short Bigeye back to the tank – safely in a large clear plastic bag so it could see the fish and the new fish could see the predator.
Finally, Short Bigeye was released from the plastic bag and allowed free rein in the tank. The new fish were seldom seen for the first few days, according to Hoffman. After everyone settled in, the new fish can be seen swimming around, keeping watch on Short Bigeye.
“Now, everybody’s happy,” Hoffman said, though Short Bigeye still likes to test the new fish. If one hesitates, though, Short Bigeye will have itself an expensive snack.
Hoffman isn’t done adding to the Oculina tank. He has plans to introduce some invertebrates, including pencil urchins. A specific type of hermit crab, too, could be added. Hoffman hopes to acquire the creatures without the expense of diving deep to get them.
He said some of the Oculina Banks residents can be found in a wide range of depths, including some that hover near the water’s surface. Collecting those would save on costs and still represent the life found in the reef.
Hoffman explained that part of the reason why deepwater fish are so expensive has to do with the amount of time it takes to decompress while returning to the surface. Just as divers need to take their time ascending – or risk getting the bends – fish with swim bladders face the same risk.
Now, the Oculina tank at the aquarium is not pressurized to the 200-to-300-foo level. Hoffman explained that once fish have been successfully decompressed, they can live comfortably in a normal pressure environment. What’s more critical to deepwater fish environments is the water temperature. So the Oculina tank hovers in the low 60s.
To replicate the deepwater environment, the aquarium has purposely used little lighting within the tank; most light cannot reach as far down as the reef. In order for visitors to see the tank’s residents, they can use provided red LED flashlights. The red light allows us to see the creatures, but the creatures don’t see the light, so they’re not disturbed by it, according to Hoffman.
The new fish joined not only Short Bigeye, but also a Wrass Bass, as well as a Spotfin butterfly fish and a Longsnout butterfly fish.
The Oculina Banks ecosystem exhibit isn’t the only area of the aquarium to get an upgrade. The aquarium recently installed digital frames at each exhibit to provide supplemental information as well as videos about the exhibit’s inhabitants. “Nature doesn’t always jump out at you,” Hoffman said, lamenting that many visitors don’t stand long enough at each exhibit to fully investigate. “We need people to look close.”
He sees the St. Lucie aquarium’s purpose as being a place for residents to learn about the hidden ecosystem. Other aquariums boast the large animals – sharks, manatee – critters that get the oohs and aahs. The local aquarium focuses on the small – sometimes microscopic – animals.
“That’s really our niche here,” Hoffman said.
The Smithsonian Marine Station teamed with St. Lucie County and other community partners to create this unique educational facility. The exhibit is an outreach effort of the Smithsonian Marine Station, a branch of the Smithsonian Institution’s National Museum of Natural History. For more information, visit www.stlucieco.gov/Aquarium.
The Smithsonian Marine Ecosystems Exhibit is located in the St. Lucie County Aquarium at 420 Seaway Drive on South Hutchinson Island in Fort Pierce. For information, call 772-462-3474.