The Nature Conservancy’s newly released Atlas of the Reefs of West Maui says West Maui’s nearshore waters harbor some of the state’s best remaining reefs but also documents “significant declines” in the abundance and diversity of marine life over a 20-year period.

The first-of-its-kind report includes survey data collected from 1999 to 2019 by public and private organizations at more than 2,450 sites stretching nearly 24 miles from the Pali Tunnel on Honoapiilani High­way to Lipoa Point north of Hono­lua Bay, according to a news release. Focus areas included Olowalu, Lahaina, Hanakaoo, Kahekili in North Kaanapali and Kahana.

Eric Conklin, marine science director for the Nature Conservancy’s Hawaii chapter, said the report is intended to help federal, state and community partners strengthen coastal management in West Maui, which has been subjected to some of the same pressures affecting other nearshore regions in Hawaii, including land-based pollution, invasive species, overfishing and climate change.

“While the Atlas has documented a concerning decline in the health and abundance of West Maui’s reefs and nearshore fisheries, it is already informing local efforts to manage and restore West Maui watersheds, Honolua Bay and an area stretching south from Kaanapali,” Conklin said in a news release.

West Maui communities and the state Department of Land and Natural Resources’ Division of Aquatic Resources have been working to restore the region’s coral reefs and fisheries, and officials said the atlas shares understanding “of how, when and where the reefs have changed so that they can develop targeted and effective strategies to reduce local pressures, increase reef resilience and restore reef fisheries,” the release said.

“It is already helping local managers decide where and how to reduce threats to West Maui reefs, including the impacts of climate change such as warming ocean temperatures and rising seas.”

DAR biologist Russell Sparks said the report will assist in developing effective management plans to restore marine resources and achieve the shared goal of effectively protecting 30% of nearshore areas by 2030.