The Matson molasses disaster killed more than a thousand colonies of coral, Hawaii News Now has learned.
The September spill's damage to the Honolulu Harbor's coral system extended beyond the waterway, according to the state Department of Land and Natural Resources.
"There was quite a bit of coral damage around the Matson facility (and) across the harbor on the Pier 38 side," said Alton Miyasaka, aquatic biologist with the state Department of Land and Natural Resources.
"There was also some damage on the Sand Island side of the entrance to the harbor going into Keehi."
Environmentalist have long suspected widespread die-off as a result of the spill and the DLNR's disclosure means that the damage toll will be high.
"If this is as bad as people fear, this could be a complete wipe out of the entire ecosystem," said Robert Harris, director of the Sierra Club Hawaii.
"So it's likely this will be millions of dollars in damage."
The DLNR is wrapping up a study on the impact on coral and is still assessing the amount of acreage affected. But one sources says the die-off affects more than a thousand colonies.
The September spill dumped more than 233,000 gallons of molasses into Honolulu Harbor, killing more than 20,000 fish.
The DLNR, the EPA and the Health Department are conducting parallel investigations and a federal grand jury has issued subpoenas to Matson.
Matson officials could not be reached.
Sources say that the state is looking into whether coral were killed when molasses killed when the molasses cover it, cutting off its oxygen supply. They also are investigating whether the sugar in the molasses mixed with the oxygen, making it difficult for the coral to absorb the oxygen.
Some of the coral killed by the spill were some the more common -- and less valuable -- species that live in the harbor. But the indirect impacts of the deaths of those coral on the harbor's ecosystem have not yet been calculated.
Sources said that a recent study by the state Department of Transportation uncovered a larger than suspected inventory of coral in the harbor and a subsequent study conducted by the state found even more coral existing in the harbor.
But a post-spill review found an extensive die-off, the sources said.
The disclosure comes as the DLNR is seeking to expand its rules to make it easier to fine anyone who causes extensive damage to coral.
The proposed rule is partially in response to derelict boats that run aground and damage coral but it also could apply to future harbor spills.
"It's easier for us to determine when a violation occurs and to assess fines and hopefully change behavior," said Miyasaka.
The DLNR is holding a series of hearings on the new rules around the state and could present a draft to its board for approval in January before going to the governor for signing.