Hawai'i's coral reefs shelter thousands of marine plants and animals and protect shores from erosion. They create the Islands' legendary surf and are critical to the state's marine tourism industry.

Coral reefs, sometimes called the rain forest of the sea, also are under enormous stress from threats ranging from pollution and alien species to overfishing and recreational overuse.

"They're valuable, they're awesome, they're spectacular, and they're in trouble," said Randall Kosaki, research coordinator for the Papahanaumokuakea Marine National Monument.

The state and counties tomorrow will kick off an environmental campaign that aims to educate the public about the importance of — and how to protect — Hawai'i's coral reefs.

The International Year of the Reef is a yearlong, global campaign to raise awareness about the value of coral reefs, as well as the threats to them. The previous International Year of the Reef campaign in 1997 drew participation from more than 225 organizations in 50 countries and territories.

The state is partnering with public, private and nonprofit groups to hold a series of events throughout the year that will focus on bringing attention to the ecological, economic, social and cultural value of coral reefs, Gov. Linda Lingle's office said. Events include teacher workshops, beach cleanups and other reef-related outreach programs.

Tomorrow's campaign kick-off will include educational booths, displays and demonstrations on the state Capitol's fourth floor.

Hawai'i has hundreds of thousands of acres of living reef, home to more than 5,000 known species of marine plants and animals. About one in four of these species is found only in Hawai'i. With new genetic tools and more intensive sampling, the number of known species could easily double, said Alan Friedlander, Pacific coral reef science coordinator for National Oceanic and Atmospheric Administration's biogeography program.

The net benefits of Hawai'i's coral reefs have been estimated at $360 million a year, with an overall asset value of $10 billion.

But reefs in Hawai'i and around the world are under threat from alien invasive species, overfishing, land-based pollution and ocean debris.

Climate change — which can contribute to coral bleaching — is also a looming threat, underscoring the importance of preserving reefs. Healthy coral reefs tend to be more resilient to climate change, scientists say.

"The latter half of the 20th century has seen the decline of coral reefs worldwide and here in Hawai'i, and yet we still have this problem of the sliding baseline where you just accept things the way they are as normal and the way they always have been," Kosaki said. "If you look back a generation or (more), then you realize how much damage we've done."

But Kosaki has hope, noting that the increased protection of the largely pristine Northwestern Hawaiian Islands has raised awareness about what a healthy reef ecosystem looks like.

"I'm very hopeful that through good education and outreach we can make people aware of more responsible ways to use the reef," he said.

"The Year of the Reef is a good opportunity to ... get the message out on our reefs, both good and bad. There are a lot of good things to be said about our reefs. They're valuable resources, recreationally and commercially. Culturally they're really important for Native Hawaiians."

Hawai'i's 1.2 million residents and about 7 million tourists each year have put increasing pressure on the state's coral reefs, and a number of urban areas and popular visitor spots have suffered from land-based pollution, "significant fishing pressure," recreational overuse and alien species, according to a 2008 report on "The State of Coral Reef Ecosystems of the Main Hawaiian Islands."

The report, scheduled to be released this summer, said that despite these human stressors, "many of Hawai'i's coral reefs, particularly in remote areas, are still in fair to good condition."

But that doesn't mean that everything's fine when it comes to Hawai'i's coral reefs.

Friedlander, lead author of the report, said Hawai'i's reefs are "hanging on better" than others around the world and that there are certain remote places that are faring fair to good.

But "I wouldn't say ... there's nothing to worry about, and I certainly would say there's a lot of places that need help," he said, noting the south shore of O'ahu and Maui and Kane'ohe Bay.

"Don't underemphasize the fact that where there are big human footprints, where we've got development, heavy fishing pressure, invasive species, those reefs are in bad shape."

A report focusing on the Northwestern Hawaiian Islands, which Friedlander also led, notes that the coral reef ecosystem in the main Hawaiian Islands is "in very poor condition" compared to the Northwestern Hawaiian Islands, which shows what Hawaiian reefs used to look like.

The report cited various changes that need to be made to help restore and protect reef ecosystems in the main Hawaiian Islands, including additional restrictions on "overly efficient" fishing gear types such as gill nets and scuba fishing.

Friedlander said more community-managed and marine-protected areas are also key to helping protect and restore coral reefs. The report said sediment discharge is probably the leading land-based pollutant that is altering the reef ecosystem here, and that best management practices to reduce sediment runoff should be followed as coastal development expands.

Hawai'i also needs to invest more in preventing the spread of alien algae, the report said.

The Northwestern Hawaiian Islands also are vulnerable to poaching and long-term threats such as disease, sea-level rise and coral bleaching associated with climate change, the report said.