There are lots of books, popular and technical, on the colorful fish of the Hawaiian reefs, a number on shells and other invertebrates, and even some on the Hawaiian cultural uses of marine resources. But there are few comprehensive books on the plants of the reefs.

That's a little like bird-watching and not noticing you're in the forest.

A new volume, "Hawaiian Reef Plants," produced by the University of Hawai'i Sea Grant, steps into the void, striding the line between popular and scientific, providing photographs that will help the average beach-goers identify the seaweeds they're seeing, and enough technical detail to satisfy more accomplished sea folk. It's a 264-page paperback listed at $24.95.

If you've been impressed by shapes of the corals and the variety of fish on the reef, consider the algae. You've got your reds, blue-greens, greens and browns. You've got big leafy ones, stout rubbery ones, ones that wave like hair in the current, and rocky forms that on some shores are more important for building reefs than corals.

The authors, Australian botanist John Huisman and University of Hawai'i botanists Isabella Abbott and Celia Smith, open with a short course in marine botany, plant identification and other information, and strongly make the point that while the book identifies individual plant species, the overriding key for understanding them is the reef as a community.

"Let's not be simplistic. Our marine plants live or die as members of complex ecosystems of interacting plants, animals and physical factors," the authors write in their foreword. They warn readers that the book "will occasionally lead you into that wider world of fishes and coral, tourists and industrialists, and limu pickers."

The volume discusses pollutants, aggressive alien seaweeds, Hawaiian cultural uses, how to avoid becoming part of the problem on Hawaiian reefs and more.

If you decide to become a student of Hawaiian seaweeds, the book has tips on how to collect them, including how to press specimens so you can keep them for years.

A few other books contain useful information on seaweeds although some may be difficult to find. Among them, "La'au Hawai'i: Traditional Hawaiian Uses of Plants" and "Marine Red Algae of the Hawaiian Islands," both by Abbott, "Plants in Hawaiian Culture" by Beatrice Krauss, and "Seaweeds of Hawai'i, A Photographic Identification Guide," by William Magruder and Jeffrey Hunt.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.