Hawaii’s coral reefs are dying, and researchers are a few steps closer to figuring out just how much environmental changes and human interaction affect the ocean’s coral reefs.

Researchers from the Ocean Tipping Points project published a new study Thursday after analyzing 10 years of data that examined how sedimentation, development and fishing affect coral reefs in Hawaii.

“When we jumped into the water in west Hawaii, over half of the coral reef was dead,” said Lisa Wedding, a lead author on the paper to Stanford University.

“These are some of Hawaii’s most vibrant coral reefs, so we were heartbroken – and determined to better understand how reef ecosystems could be more resilient in the future.”

On Oahu, researchers found that human activity, such as fishing and coastal development, were the biggest irritants. On less populated islands, sedimentation and runoff were bigger factors.

The research team’s findings will be used to develop strategies to effectively address local impacts based on dominant factors, and begin the process toward restoration.

“This area of research has been a long-term need for coral reef conservation and management,” said Joey Lecky, co-author of the study and analyst for NOAA Pacific Islands and Fisheries Science Center to Stanford University.

“These findings will allow us to take a big step forward in understanding how corals are impacted by both human activities and by environmental stressors, in a place with incredible value,”  Lecky said.