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Hawaii's romantic atmosphere apparently has no effect on Halimeda, a green algae that lives in Hawaii and Florida reefs. Puzzling algae:
Lots of sex in
Florida but
none in HawaiiBy Helen Altonn
Star-Bulletin
The Florida species reproduces sexually, but strangely, the Hawaii species doesn't, says Celia Smith, University of Hawaii-Manoa botany professor who has studied Halimeda for many years in the two states.
"We can go into the field (in Hawaii) year after year after year and never see plants reproducing. In Florida, the same species or other species reproduces so obviously we can see it."
Smith believes the Hawaii plants may be clones -- reproducing from tiny, viable fragments torn by waves or bitten off by fish.
She recently spent 10 days in Florida on a deep-sea study of the algae, living with three other scientists in Aquarius, the world's only undersea research laboratory.
Four others on her team dove from a day boat doing shallow reef work in parallel with the ocean bottom research.
"Team Halimeda" included four UH graduate students: Peter Vroom, Jennifer Smith, Ryan Okano and Erica Klohn.
When Okano and Klohn returned they joined the vessel Rapture, which left here Sept. 19 for ecosystem studies in the Northwestern Hawaiian Islands.
Celia Smith was involved in planning the expedition as one of the principal investigators, but she couldn't go. She was enjoying an "experience of a lifetime" in the Aquarius.The habitat is on the seafloor, 60 feet below the surface and 3.5 miles off Key Largo in the Florida Keys National Marine Sanctuary.
Divers can live in Aquarius for as many as 10 days and spend long periods in the deep ocean without having to do deep-compression diving. Diving from the surface, they're only able to work about two hours in the water, Smith said.
Her team members started diving about 7 a.m. and were in the water until about 6 p.m., with one interval in the Aquarius.
"That is just an unbelievable gift of time for a scientist," she said.
Her group has used Aquarius for four years for research. One other year, when the habitat wasn't available, they dove from the surface.
Other UH scientists also have done research from the unique habitat, which has a laboratory, bunks, kitchen, gazebo and outdoor "lanai."
Smith's team this year included scientists from Florida, the Netherlands and the Isle of Shoals Marine Lab off Maine's coast.
She began studying Halimeda in Hawaii in the early 1990s. The flora are part of the typical reef algae and play an important role as food for many species of fish, she said. The widespread calcareous plant also produces sand and stabilizes shifting sediments.
Smith discovered that tiny pieces of Halimeda "have great viability." For instance, she explained, a fish can take a bite of alga and spit it out and "it may be extremely small, something on the order of a push-pin or a paper hole punch, and it is still alive."
It can live and grow into a whole new plant, she said.
Vroom's dissertation is on the plant's genetics, which may show the Hawaii population operates differently from Florida's algal system, Smith said.
Her work indicates clones from fragmentation may be more important in spreading the species in Hawaii reefs than in Florida, she said.
However, there is a likelihood that genetic analysis will detect new individuals in the Florida material as a result of fertilization, she said.
"Even more intriguing, fertile Halimeda have been seen in the Northwestern Hawaiian Islands. This raises the stakes. How is it that plants there, where the water is colder, are fertile and apparently not fertile here?"
Resolving such fundamental biological issues is important to management and protection of the plants, she said.
University of Hawaii
