Class is in Session Aboard the ‘Discovery’

Three times each week, the 36-passenger pontoon boat Discovery makes its way down the 3/4-mile channel that leads from FAU Harbor Branch Oceanographic Institute’s dock into the Indian River Lagoon.

Part of Florida Atlantic University since 2007, the 50-year-old marine research powerhouse now offers educational boat tours to the public. Discovery is unique among HBOI’s 17 vessels (15 boats and two Jet Skis) in that it is boarded by visitors; the rest of the fleet is used exclusively for research and for rescue of marine animals in distress.

When the 30 inquisitive participants climb aboard, they find that the vessel is equipped with seatback screens that display photographs, videos, and live footage relayed from remotely operated vehicles. The covered yet open configuration of Discovery allows guests to be sheltered from the sun yet refreshed by the coastal breeze.

Samantha McGuire, who holds a master’s degree from FAU in marine science and oceanography, conducts tours on Discovery as part of her job at Harbor Branch. Throughout the 90-minute excursion, she talks science and research, deftly managing to acquaint first-time international visitors with the Indian River Lagoon while still keeping it interesting and informative for lifelong Treasure Coast residents. “Fun facts” just seem to roll off her tongue, on subjects from mangroves to mullet to manatees to … inky-black solitary tunicates.

As the boat enters the lagoon, it passes four channel markers. A brown pelican alights onto one, giving McGuire the opportunity to drop the first of several morsels of information about these quintessential Florida birds: A brown head and neck indicate a juvenile, while an adult brown pelican sports a white head and neck.

Atop another pylon perches a large apparatus that looks as if it may be picking up Radio Free Europe. It is part of IRLON, McGuire explains, the Indian River Lagoon Observatory Network of Environmental Sensors. The instruments gather data from sensors several feet underwater and upload them so that scientists can monitor water quality—a major part of Harbor Branch’s mission—in real time. Many parameters are measured, including water temperature, salinity, pH, oxygen saturation, and levels of nitrates and phosphates. IRLON is a powerful tool in determining how well lagoon restoration efforts are working. Harbor Branch makes the real-time data available to the public at irlon.org.

The next subject to come up in the floating classroom is mangroves, and there is nothing like having the instructor point to each type—red, black, and white—in its natural habitat to help the students retain the knowledge. And it’s a good thing, too, because there will be a brief verbal quiz when Discovery passes another mangrove island later in the tour.

Mangroves play several crucial roles in our ecosystem; their sturdy, elaborate root systems ward off erosion, help filter water, and provide good fish nursery habitats.

As more pelicans appear, McGuire nonchalantly reveals some more fun facts about them: They can dive from an altitude of up to 60 feet, and she has had the pleasure of watching young pelicans prepare to enter the diving big leagues. “Juvenile pelicans practice their diving skills by standing in shallow water, typically along the small islands in the lagoon, tilting their heads, jumping, and landing headfirst in the water.” The head tilt is part of a technique they must hone in order to avoid neck injuries.

Further, she says, “You know they are successful in catching a fish if they lift their heads back to swallow a fish after slowly draining the water from their bills.” That pouch pelicans are known for can hold up to 3 gallons!

McGuire has an uncanny ability to cover all of the “scripted” material that is part of the tour while nimbly commenting on the changing surroundings. Ideally, some dolphins and manatees will show up, but they may not. On the other hand, some species can more or less be counted on, such as a generous selection of birds. “Birds never fail us,” McGuire says. 

Another opportunity for McGuire to respond to the vicissitudes of nature comes when the onboard staff give the passengers a look beneath the surface of the lagoon. Two small remotely operated vehicles, “Stinger” and its backup, “Minnie,” are used by researchers to keep an eye on and in the lagoon, and a demonstration is part of the tour.

Depending on conditions, the seatback screens display live or, occasionally, pre-recorded footage. While the locations are preselected, one never knows for certain what the ROV’s fish-eye lens will pick up in its nearly 180-degree field of vision. Onboard assistant Madison Bennett deploys the ROV, and guests are given an up-close view of the underwater landscape.

Some of the interesting sights to pop up on the screens have been stingrays, curious manatees examining the ROV, octopus dens in the seagrass beds, and, recently, a goliath grouper—just a youngster at about 2 to 3 feet long, but capable of growing to 800 pounds.

One of the major applications of the ROVs is observation of seagrasses, an important part of the lagoon habitat and the primary food source for manatees and turtles. Harbor Branch grows seagrasses in aquaculture for the purpose of restoration, and progress can be monitored visually with the ROVs.

Another tool used to demonstrate research techniques is a small, simple net made of a fine mesh. Bennett deploys the net, allowing it to trail along beside the boat for a minute and a half on each side. In just three minutes, the net collects thousands of organisms. Now, many of these creatures are not particularly impressive or even discernible to the naked eye; but they do offer a tiny window into the staggering diversity of life in the Indian River Lagoon.

McGuire selects a comb jelly, a colorless creature a few inches across, and places it into a petri dish. She passes it around for everyone to examine and touch as she discusses plankton—a collective term for organisms, usually minute but not always, that are unable to propel themselves to any significant degree but rather float passively with the current.

McGuire has a way of injecting humor into subject matter that is not necessarily intrinsically entertaining. While on the subject of invertebrates such as marine snails, she mentions the lightning whelk, shows a sample of its egg casing, and divulges that the first one to hatch eats its siblings. “That probably makes for some awkward family dinners,” she jokes. 

Shortly after the comb jelly is returned to its brackish home, a mullet hurls itself out of the water with abandon, presenting McGuire with an opportunity for a fun fact, or, in this case, more of a fun speculation, since there is no definitive answer to the question “Why do mullet jump?”

McGuire cites several schools of thought on the subject. Perhaps they are attempting to escape predators. It may be a method of flushing their gills or ridding themselves of parasites. “Or maybe they’re just happy!” she posits.

Harbor Branch’s Discovery tours offer local residents and visitors of a curious bent an opportunity to learn about our lagoon in a scientific yet relaxed atmosphere, sure to disembark armed with important ecological knowledge as well as answers to such questions as “Why do anhingas and cormorants need to hold their wings out to dry?” and “How do manatees sleep?” 

Fun Facts:

• Florida’s state shell is that of the horse conch, Triplofusus giganteus.

• The bottlenose dolphins of the Indian River Lagoon are a genetically distinct population from those in the ocean.

• More than 15 species of sharks and rays live in the Indian River Lagoon.

• The animals with the largest migration distance of all (relative to their size) are microscopic zooplankton, whose migration is entirely vertical within the water column.

Discovery Tours

Fridays 10:30 a.m., Saturdays 10:30 a.m. and 1 p.m.

$40 per person

FAU Harbor Branch Oceanographic Institute

5600 N. U.S. Hwy. 1, Fort Pierce

772-242-2293

fau.edu/hboi/bookatour