PENOBSCOT THE FOREST, RIVER AND BAY, edited by David D. Platt, Island Institute, Rockland, Maine, 1996, 204 pages, $14.95.

At first glance, Island Institute’s new book “Penobscot The Forest, River and Bay” looked like a textbook — a dry tome. The 204-page paperback volume lacks the glossy color photos that make the Rockland group’s annual publication, Island Journal, so alluring.

But that first visual impression soon became trivial, unimportant. What the book lacks in appearance, its depth of content makes up for many times over.

Edited by the institute’s publications director, David Platt, the book teaches the reader in clear, crisp language just how the forest, river and bay — in particular the Penobscot River, Penobscot Bay and Penobscot region’s forests — are intrinsically related and reliant on one another’s health.

The book’s focus on the Penobscot region geographically orients readers, provides a historical framework, outlines the region’s human and natural resources, and identifies social and environmental issues. It could serve as a model to heighten awareness about other regions in Maine or, for that matter, the entire state.

The depth and breadth of “Penobscot” also reflects Island Institute’s expanding role in Maine. Since its founding in 1983, the group has aimed to forge ties among Maine islands and to help islanders deal with a scarcity of year-round jobs, lack of affordable housing, and other problems.

In recent years, however, the institute’s mission has expanded to include not just islands but Maine coastal towns and related industries such as fisheries, aquaculture and timber harvesting.

Island Institute President Philip Conkling has written extensively about Maine’s lobster, herring and sea urchin fisheries. He has assisted the Department of Marine Resources in dividing the Maine coast into zones in an experiment giving Maine lobstermen some authority to regulate their own fishing grounds. He also has written “From Cape Cod to the Bay of Fundy: An Environmental Atlas of the Gulf of Maine.”

So Conkling’s voice carries weight along with those of the other contributors in “Penobscot.” They range from Ted Ames, a longtime Stonington fisherman who is also the institute’s marine resources director, to the University of Maine’s maritime history professor, John Battick.

Throughout the book, an effort has been made to balance the positive with the negative.

On water quality in the Penobscot River, Platt and Freeport writer Bob Moore report water quality is less of an issue today than it was 30 years ago when dams and untreated waste water depleted the amount of dissolved oxygen in the entire waterway.

But they warn that runoff from farm fields, septic systems and other “nonpoint” sources of pollution throughout the vast Penobscot watershed are of concern today.

“Very little is known about the impact upstream pollutants have on the marine environment,” they say. “What is known is that chemicals and heavy metals that were discharged at much higher rates in the recent past have accumulated in the flesh of aquatic life in the river and bay.”

In “Penobscot,” then-and-now sketches are provided of East and West Penobscot Bay towns and river and island communities in the region.

“If this book imparts new knowledge or deepens our existing understanding of the factors that have made the Penobscot region what it is today, as well as the trends that are likely to shape it in the years to come, it will have achieved its purpose,” states the book’s preface.

“Penobscot” does just that.

The book is a valuable resource book for residents, educators, town officials, businesspeople and others with a stake in the region’s future. It is available in bookstores and through Island Institute, 410 Main St., Rockland 04841.