What's It All About?... Algae by Cheryl Ernst Hawai'i industry depends on healthy reefs, which depend on healthy algae.

About once a month, busy scientist and teacher Celia Smith makes it to the beach. Sun worshippers are stretched on their towels, book lovers lounge under shade umbrellas, water fans cavort in the gentle waves. But Smith is here to work. She dons a blue wet suit and snorkel gear and heads out to check on what she considers one of marine biology's most fascinating organisms.

Algae.

The stuff that slimes fish tanks, fouls Maul beaches and coats marine equipment? Yes, but also the base to the ocean food chain, stabilizer of coastal reefs and producer of much of the world's oxygen.

Ancient, though not necessarily primitive, algae are photosynthetic organisms with simple reproductive structures but prolific and sometimes complex propagation schemes. Predominantly ocean growers, algae are divided into two major groups. Unicellular micro-algae include phytoplankton and zooxanthellae, which live symbiotically within the cells of reef-building corals. The rainbow of macro-algae includes the green ancestors of land plants; the browns, like limu kala, that help establish ocean ecosystems; and diverse reds, like the prized edible limu kohu.

For decades, some Pacific algae were assigned the names of the Caribhean species they most resembled. Isabella Abbott, UH's Wilder Professor of Botany changed that, anointing newly identified Hawaiian species with more appropriate names like Peleophycus, or Pele's seaweed, and Naccaria hawaiiana.

A UH alumna, Smith studied at Stanford with Abbott, a respected ethno-botanist and phycologist, or algae expert.

Smith now nurtures tomorrow's bright, young scientists.To Smith, it's payback. A National Science Foundation summer program for high school students placed the Boston Yankee in a University of Massachusetts research lab working with plant hormones. One of the scientists hired her at a marine station the next summer. Hooked, she studied ocean plants in North Wales, at Stanford and at UC Berkeley. She was doing postdoctoral work at the Smithsonian when she was offered a UHM botany position.

The Smithsonian tapped Smith's talent again while collecting material for its Ocean Planet exhibit. (The exhibit opened in Washington, D.C. last spring and will tour 11 cities, visiting Honolulu July 12-Oct. 5, 1997.) Smith had assembled a research crew for 30 days of in-depth research on the green Halimeda algae using the National Oceanic and Atmospheric Administrations Florida-based aquarius research station. Her work is mentioned in the magazine accompanying the exhibit.

Smith and two other divers worked from the surface to study dispersal of the algae at a research site 20 feet down. Five others lived in and worked out of the 13 by 43 foot underwater station anchored at 50 feet, where more fish graze and the water is quieter. To stay at that depth. divers have to be "saturated," a process in which nitrogen levels increase in the hloodstream. The process has to be gradually reversed before divers call re-surface.

Why all the effort? Although common in salt water aquariums and shallow O'ahu waters, Halimeda is some thing of a mystery plant. Strings of lobed structures is really one giant cell.To survive, the plant must quickly close wounds inflicted by human picking, fish bites or wave action. Sexual reproduction is possible but Hawaiian species more often propagate by cloning. The problem with cloning, says Smith, is a resulting lack of genetic diversity. An entire population of genetically identical individuals is more likely to succumb to disease or other threat than is a population of differing individuals.

Another problem is that out-of-control vegetative reproduction creates smelly alagal blooms. Improved understanding of algae will help scientists prevent or respond to such episodes.

Smith also works on projects related to biofouling and coastal zone management. "The beauty of this institution is our ability to collaborate. This is clearly the way science will move forward," she observes. The international biofouling group, which includes zoologist Michael Hadfield, is testing non-toxic surface coatings that discourage algae and invertebrates from growing on man-made structures. Another team, which includes UH post doctoral candidate Cindy Hunter, is studying coral bleaching. Corals lighten when algal cells lose pigment or are expelled in response to stressful conditions, such as warm water, ultraviolet light or coastal runoff.

The study is important, Smith says, because Hawai'i industry, from fishing to marine transportation to tourism, depends on healthy reefs.

"There are not many other places in the U.S. where scientists can do this work," she add. "We need to do it. We're the only U.S. research university in the Pacific that sits in a warm-water region."

From: Malamalama 20(1), Winter 1996