SEAWEED, THE OCEAN'S UNSUNG GIFT

 Already a billion-dollar industry, lowly seaweed bursting with nutrition and new resources may soon assume a high place in a world starving for both.

               Memorials to women or to foreigners are rare in Japan. Yet overlooking Ariake Bay is a bronze plaque to Dr. Kathleen Mary Drew of Great Britain. How did she earn this unusual honor? By her research on a modest plant we usually dismiss as just “seaweed.”         

              Today, in a world running short of conventional food and industrial chemicals, lowly seaweed is emerging as dark-horse candidate. It is almost as if weeds had suddenly become a cash crop.         

          This is heady status for a plant that bears no flowers of fruit, exudes no exotic perfumes, inspires few poets. Lying in mounds on a summer beam, ringed by buzzing insects, seaweed does indeed seem undo spire But would we judge a redwood tree on the basis of one branch adrift at sea?

          My own attitude toward seaweed changed abruptly while I was scuba diving off California. Friends encouraged me to dive into underwater"forests" of brownish kelp. The plants that lay shriveled on the beach unfurled under water into 50 to 60 foot vines that swayed in unison with passing swells. The silent motion at first seemed menacing, but the eerie mood gradually ebbed Under water, the sprawling kelp that formed a dense canopy on the surface divided into arborlike columns. The kelp's brown cast, which looked so dull on the bench, glowed golden under the sunbeams that filtered through the canopy. No rustling forest in autumn color could rival this submarine radiance.

         I hovered in the water, like a hawk in a summer updraft, ant watched schools of fish pass like rain showers. A seal torpedoed toward me, then veered away in a flashy somersault. A pelican dropped from the sky in a cascade of silvery bubbles to gulp a billful of smelt. Ever since that day, I have preferred my forests under water, where I needn't worry about blisters on my feet. And between "hikes" in the kelp forests, I have tried to learn more about the seaweeds— "marine algae," scientists call them —of the world's oceans.

           While their structure appears similar to land plants, marine algae lack true stems, roots or leaves Some species float free, but a rootlike "holdfast" anchors the giant kelp plant to the seabed. Leaflike "blades" dangle from its sternlike "stipe." Many algae are dainty, lacy plants that glisten like living jewels in tidepools. Their nicknames— mermaid's hair, pearl moss, sweet tangle, feather boa, fairies' butter— reflect this beauty.

         The giant kelp that forms my be loved submarine forests is the largest seaweed, weighing up to 300 pounds and able to grow over 100 feet long. Gas-filled bulbs at the base of each blade help buoy up the massive plants. (As a boy, I case tile dried bulbs into campfires, where they resounded like firecrackers.) Giant kelp's stipes can streak coward the sunlit surface at a rate of two feet a day. No ocher marine plant can grow so rapidly.

          By providing food and shelter for marine life, marine plant communities become a critical link in the marine ecosystern. Giant kelp forests sustain three times the amount of life that a rock reef supports. Up to 90,000 juvenile fish may exist in an acre of kelp forest. Even in death, marine plants sustain life. Drift kelp encrusted with juicy organisms becomes a prime food source for bottom feeders and for inshore marine communities.

         To understand how most seaweeds gain their energy, you have to turn landside botany upside down. The blades gee energy from the sun and extract nutrients from the surrounding water instead of the seabed. The nutrients tray el down the tubular stipes to nourish new growth at the holdfast base. Special blades at the kelp's base release billions of like spores, a tiny fraction of which attach to the seabed and grow into mature plants.

          Though the commercial potential of most species has hardy begun to be tapped, seaweed is already a billion-dollar industry. In many parts of the world, brown kelp is harvested and processed into a beige powder called algin. A teaspoonful of algin—a gel-like substance or plant gum—can make a quart of water thick as honey. As a chemical fastener, or colloid, it can hold in moisture present in prepared foods ant medicines, prevent synthetic products from separating or disintegrating, keep the icing on a cake and the head on a beer without affecting flavor or color.

             There are other useful marine colloids, such as carrageenan, which is contained in Irish moss, a reddish, parsley-like alga. Remember when you had to shake chocolate milk in a bottle before drinking it? Carra-geenan now keeps the chocolate in suspension. It also keeps our tooth| paste and mascara from running.

              Another small red alga, Gelidium, produces the highest-priced colloid, I called agar, an algal gel used to I culture bacteria for medical purposes. Prior to World War II, Japan had a near monopoly on the agar trade. Japan's famed women divers, the ama, helped pioneer the subtidal harvest of prune agar-bearing seaweeds. Today, Spain and Portugal, with seaweed stands in the Azores and Morocco, are major agar producers.

           Chile, the Philippines, Argentina, Ireland, Taiwan and Indonesia harvest their abundant kelp stocks for export to industrial nations. Canada is the world's third largest Exporter, and has helped support research programs on the culture of marine algae. France and England extract algin from a smaller brown seaweed, Laminaria, first used as a source of fertilizer, cattle feed and iodine. Denmark has its own carrageenan industry based on a native seaweed, Furcellaria.

          Japan uses the small, red alga Gloiopeltis as a source of high-quality glue in the sizing of fine silks and textiles and even in wall plaster and tile cement, producing 1.1 million pounds of the paste each year. In Taiwan, farmers collect Gracilaria cuttings on the "wild" shore. The cuttings are cast into tidal enclosures originally built to raise fish. Held in place by a fishnet cover and fertilized with pig manure, they propagate into adult plants harvested for food and exported as an agar source.

        Many people—those of Asian and Polynesian cultures in particular —prefer to dine on their seaweed, and, in a world fast outstripping its conventional food sources, some experts feel seaweed will play an ever more critical role in global diets. Eating the cast weed that “litters” our shore may not appeal to you. It didn't to me either until I was introduced to poki, a popular party snarls in Hawaii, Poki consists of raw tuna sprinkled with a crisp red garnish called ogo, a small red Gracilaria delightfully celerylike in taste. Bins full of ogo sometimes compete with lettuce for display space in Hawked supermarkets.

       Ancient Hawaiians used more than 20 species of limu (Hawaiian for edible seaweed), rich in minerals and essential trace elements, to en liven their rather steady diet of fish and poi, including the treasured kohu, favorite of Hawaii's king. (One taste of pungent, penetrating kohu about knocked my socks off.)

          Agar, or agar-agar, as it is sometimes called, is also widely used throughout Asia for culinary purposes. Its setting properties arc utilized in delicious gelatins dessert and iced drinks.

         Japan's passion for seaweed is well known. Japanese kelp seaweed, called kombu, is used to flavor rice for sushi and is pickled as a relish. Seaweed also gives a distinctive taste co vegetarian dishes. Long before the term "aquaculture" became fashionable, Japanese coastal villagers were learning to cultivate nori, an alga often sold in purple-colored pressed sheets. These pioneer sea farmers first grew young plants on bamboo stakes and then shifted them to nets laid horizontally above the shallow seabed.

         In 1949 England's Dr. Drew identified the microscopic spore-producing state of Porphyra, the plant from which nori is made. This discovery enabled the Japanese to "seed" their nets and extend production into deeper, less polluted waters. In 1947 Japan produced about 860 million sheets of nori. Today, thanks in part to Dr. Drew's research, Japan produces seven billion sheets annually. Nori culture is the country's largest single inshore marine fishery, constituting a billion-dollar-a-year industry. Be~ause of its culturing efforts on brown seaweed (Laminaria), China today is the world's lading producer of seaweed—valued at some $300 million annually.

           Seaweed farmers enjoy major advantages over their landside counterparts. They don't have to worry about soil erosion, drought or subdividing land. Nor are expensive fertilizers needed; the surrounding sea provides the basic nutrients.

         Kelp, the plant that first revealed to me the charms of seaweed, is now inspiring visions of ocean energy farms. The Gas Research Institute in Chicago (GRI), supported by private natural gas companies, is studying giant kelp as one biomass fuel candidate. GRI also sponsors experimental kelp plantings off the California coast.

       At least two more marine bid mass Mel candidates are being evaluated for GRI—Gracilaria, the source of ogo and an alternative source of agar, and free-floating Sargassum. Unlike giant kelp, these smaller algae do not require costly support structures. Marine biomass candidates have a major adventage over such landside candidate as sugar cane and wood the ocean offers far more growing space at much less cost.

       Ironically, while seaweed farms expand, some native or wild stands can recede drastically. Recently, some of Southern California's popular kelp forests receded, impairing the activities of fishermen, skindivers and the kelp harvesting industry. Fishersmen and hunters had depleted animal stocks that once controlled sea urchin and other kelp grazers. Possibly urban sewage discharges were also reducing the amount of sunlight reaching the blades, ant suffocating bottom growth. (Last year the kelp bets were havocked by El Nino, a massive oceanic and atmospheric disturbance generated by the unusual warming of Pacific waters.)

         A number of areas, including Japan and Hawaii, have already been threatened by the decimation of wild seaweed stocks. Inexperienced pickers can yank up a whole plant, ruining a kelp forest's ability to regenerate itself. Hawaiian conservation officials encourage pickers to pinch off only the top portion of the plant. In California kelp harvesters cannot cut plants beyond a length of four feet.

         Conversely, in Europe concern over unwanted seaweed invasions has become an issue. In l973 France's Institut Scientifique et Technique des Peches Maritimes (ISTPM) was experimenting with imported giant kelp in coastal Brittany ISTPM wanted to introduce the kelp to develop a prime new source of alginates. But British scientists feared that the wild population of giant algae would spread to the coast of the United Kingdom and drive out native algae and upset natural marine ecosystems. The British Admiralty was concerned that the giant kelp would constitute a new hazard to inshore navigation.

     International scientific groups also questioned the wisdom of the ISTEM proposal. France's Secretariat of Sate for the Environment has withheld permission for any further work with giant kelp. According co a paper given by Gerald Boalch of the Marine Biological Association of the United Kingdom at a 1980 International Seaweed Symposium in Sweden, "The records of where man has introduced aquatic plants from one area to another all indicate that the immigrant has gone out of control and caused problems."

        At the Marine Science Institute of the University of California at Santa Barbara, Dr. Micheal Neushul has worked to develop high-yield kelp hybirds. Hybirds, Which are generally sterile, can eliminate the uncontrolled spread of introduced or "foreign" plants.

       The work of a marine scientist at the University of California in Santa Cruz exemplifies expanding algal horizons. Dr. Judith Hansen is restoring overharvested beds of a small brown kelp in San Francisco Bay. Hansen is also working on indoor culture of Gelidium, whose depressed wild stocks contribute to the high price of medialgrade agar. "Through strain selection, we can increase Gelidium's relatively slow growth rate," says Hansen. "In enclosed systems, we find chat this plant's productivity is ten times that which occurs in wild stocks." As Hansen's research indicates, careful management of our natural marine plane stocks, combined with programs in cultured stocks, can benefit all of us.

        Like our forests on land, our marine forests can last forever with proper care. Our magnificent seaweed heritage, in “wild” sea forests and ocean energy-food farms, may prove to be an important part of our future on this watery planet.