Thanks to Mother Nature, 1990 was a very good year for the handful of companies in California that harvest giant kelp from state-owned beds in the Pacific.

The state Department of Fish & Game predicts that the 1990 harvest will be significantly higher than the 133,000 ton-harvest in 1989. Through the end of September, harvesters had taken 122,000 tons of kelp from the state's 76 beds, which stretch from San Diego to Monterey. An additional 30,000 tons were probably taken during the rest of the year, the department estimates.

Marine biologists generally view the increasingly abundant harvests of recent years as proof that the kelp beds are recovering from widespread damage that occurred in 1983, when El Nino weather conditions produced warmer-than-average water temperatures and severe winter storms tore plants from the ocean bottom.

The beds, which thrive in cool, clear ocean water, generally have benefited from an increase in numbers of sea otters that are natural predators of sea urchins and abalone, which feed upon kelp. Similarly, the fledgling commercial sea urchin fishing industry also is believed to be reducing the number of predators that feed upon kelp.

But, although the state's kelp beds are in relatively good health, commercial and societal pressures could change how the state's 68 square miles of kelp beds are utilized.

State Proposition 132, approved in November by California voters, calls for the creation of four natural preserves along the state's coastline. Kelp harvesters, commercial fishermen, recreational divers and naturalists probably will be at odds over the location of the reserves.

And, some scientists want the federal government to create a reserve that would encompass all or part of exceptionally lush beds in the Channel Islands National Park. The proposal has generated strong opposition from the state's commercial fishing industry, which relies upon the Channel Island kelp beds for a hefty percentage of its annual catch.

The scientists, pointing to declining quantities of marine species that live in or near kelp beds, also are pressing the state to reconsider regulations that govern how much kelp can be harvested from the state-owned beds that sit within California's 3-mile territorial boundary.

The wave of interest in the kelp beds is a relatively recent development, said Rob Collins, marine resources supervisor for the state Department of Fish & Game. "There are now a lot of competing uses and views . . . and one thing about Proposition 132 is that it's going to intensify (that debate)," Collins said. "It's been relatively calm in the past."