The Nature Conservancy of Hawai'i has published a new colorful and informative primer on Hawai'i's coral reefs, aimed at explaining why their protection is important.

"The Living Reef," a joint project of the Conservancy and the state Department of Land and Natural Resources, in cooperation with Malama Hawai'i and with funding from NOAA's Coral Reef Conservation Program, can be viewed and downloaded from www.nature.org/hawaii.

Its key features include stunning photography, with detailed looks at the underwater world around us. Among the most poignant are two turtle images, one of a honu swimming free, the other of one struggling while trapped in a net.

One theme of the publication is partnerships — like the one between tiny algae and coral polyps that jointly build coral reefs quickly; and the one between moray eels and cleaner shrimp that act as their dentists; and the one between turtles and the tangs that clean the limu off their shells.

The text discusses the role of reefs in protecting the Islands, providing recreational opportunities and supporting fishing. There's a little geology, and a fair amount of cultural and natural history.

The message is about threats and the need to address them.

"The good news is that coral reefs are resilient. If we act in time, we can still restore this priceless natural asset," said Kim Hum, director of the conservancy's marine programs, in a statement released with "The Living Reef."

It provides examples of management schemes that haven't worked, and ones that do. And it argues for a six-part effort to improve reef quality.

Among the proposals are the encouraging of responsible fishing practices, and stopping the arrival and spread of aggressive alien species that challenge the reef ecosystem.

It calls for a concerted program to control activities on land that affect the marine environment, including updating sewer systems that eventually flow to the sea, cutting out the dumping of chemicals that run into storm drains and controlling sediment and agricultural chemical flow during storms.

The publication encourages communities to take a hand in managing their own coastal resources, but also calls on the state to improve its enforcement of coastal protection regulations.

And it urges development of marine protected areas, where marine species can thrive without being harvested.

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.